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HOW TO IDENTIFY TREES (Continued) The Hickories, Walnut, and Butternut Tulip Tree, Sweet Gum, Linden, Magnolia, Locust, Catalpa, Dogwood, Mulberry, and Osage Orange
THE STRUCTURE AND REQUIREMENTS OF TREES
What trees to plant and how
Trees for the Lawn
Trees for the Street
Trees for Woodland
Trees for Screening
The care of trees
Insects Injurious to Trees and How to
Combat Them
Important Insects
Tree Diseases
Pruning Trees
Tree Repair
Forestry
What Forestry Is and What It Does
Care of the Woodland
Our common woods: Their identification,
properties and uses
Woods Without Pores (Soft woods)
Woods with Pores (Hard woods)
AN OUTDOOR LESSON ON TREES
A good many popular books on trees have been published in the United States in recent years. The continually increasing demand for books of this character indicates the growing public interest not only in the trees that we pass in our daily walks, but also in the forest considered as a community of trees, because of its aesthetic and protective value and its usefulness as a source of important economic products.
As a nation, we are thinking more about trees and woods than we were wont to do in the years gone by. We are growing to love the trees and forests as we turn more and more to outdoor life for recreation and sport. In our ramblings along shady streets, through grassy parks, over wooded valleys, and in mountain wildernesses we find that much more than formerly we are asking ourselves what are these trees, what are the leaf, flower, twig, wood and habit characteristics which distinguish them from other trees; how large do they grow; under what conditions of soil and climate do they thrive best; what are their enemies and how can they be overcome; what is their value for wood and other useful products; what is their protective value; are they useful for planting along streets and in parks and in regenerating forests; how can the trees of our streets and lawns be preserved and repaired as they begin to fail from old age or other causes? All these questions and many more relating to the important native and exotic trees commonly found in the states east of the Great Lakes and north of Maryland Mr. Levison has briefly answered in this book. The author’s training as a forester and his experience as a professional arboriculturist has peculiarly fitted him to speak in an authoritative and interesting way about trees and woods.
The value of this book is not in new knowledge, but in the simple statement of the most important facts relating to some of our common trees, individually and collectively considered. A knowledge of trees and forests adds vastly to the pleasures of outdoor life. The more we study trees and the more intimate our knowledge of the forest as a unit of vegetation in which each tree, each flower, each animal and insect has its part to play in the complete structure, the greater will be our admiration of the wonderful beauty and variety exhibited in the trees and woods about us.
J.W. TOUMEY,
Director, Yale University Forest School.
New Haven, Conn.,
June, 1914.
HOW TO IDENTIFY TREES
There are many ways in which the problem of identifying trees may be approached. The majority attempt to recognize trees by their leaf characters. Leaf characters, however, do not differentiate the trees during the other half of the year when they are bare. In this chapter the characterizations are based, as far as possible, on peculiarities that are evident all year round. In almost every tree there is some one trait that marks its individuality and separates it, at a glance, from all other trees. It may be the general form of the tree, its mode of branching, bark, bud or fruit. It may be some variation in color, or, in case of the evergreen trees, it may be the number and position of the needles or leaves. The species included in the following pages have thus been arranged in groups based on these permanent characters. The individual species are further described by a distinguishing paragraph in which the main character of the tree is emphasized in heavy type.
The last paragraph under each species is also important because it classifies all related species and distinguishes those that are liable to be confused with the particular tree under consideration.
[Illustration: Fig. 1.—Twig of the Austrian Pine.]
How to tell them from other trees: The pines
belong to the coniferous
class of trees; that is, trees
which bear cones. The pines may be
told from the other coniferous
trees by their leaves, which are in
the form of needles
two inches or more in length. These needles
keep green throughout the
entire year. This is characteristic of all
coniferous trees, except the
larch and cypress, which shed their
leaves in winter.
[Illustration: Fig. 2.—Twig of the White Pine.]
The pines are widely distributed throughout the Northern Hemisphere, and include about 80 distinct species with over 600 varieties. The species enumerated here are especially common in the eastern part of the United states, growing either native in the forest or under cultivation in the parks. The pines form a very important class of timber trees, and produce beautiful effects when planted in groups in the parks.
How to tell them from each other: The pine needles
are arranged in
clusters; see Fig.
1. Each species has a certain characteristic
number of needles to the cluster
and this fact generally provides
the simplest and most direct
way of distinguishing the different
pines.
In the white pine there are five needles to each cluster, in the pitch pine three, and in the Scotch pine two. The Austrian pine also has two needles to the cluster, but the difference in size and character of the needles will distinguish this species from the Scotch pine.
Distinguishing characters: The tree can be told
at close range by the
number of needles to each
cluster, Fig. 2. There are five needles
to each cluster of the white
pine. They are bluish green, slender,
and about four inches in length.
At a distance the tree may
be told by the right angles which the
branches form with the main
trunk, Fig. 3. No other pine shows this
character.
Form and size: A tall tree, the stateliest of the evergreens.
Range: Eastern North America.
Soil and location: Prefers a deep, sandy soil,
but will grow in almost
any soil.
Enemies: Sucking insects forming white downy
patches on the bark and
twigs, the white pine weevil,
a boring insect, and the white pine
blister rust, a fungus,
are among its principal enemies.
[Illustration: FIG. 3.—The White Pine.]
Value for planting: Aside from its value as an
ornamental tree, the
white pine is an excellent
tree to plant on abandoned farms and for
woodlands and windbreaks throughout
the New England States, New
York, Pennsylvania, and the
Lake States.
Commercial value: The wood is easily worked,
light, durable, and will
not warp. It is used
for naval construction, lumber, shingles,
laths, interior finish, wooden
ware, etc.
Other characters: The fruit is a cone, four to six inches long.
Comparisons: The tree is apt to be confused with
the Bhotan pine
(Pinus excelsa), which
is commonly grown as an ornamental tree.
The Bhotan pine, however,
has needles much longer and more drooping
in appearance.
Distinguishing characters: Here there are three
needles to each
cluster, Fig. 4. They
are dark, yellowish-green needles about four
inches long. The rough-looking
branches of the tree may be seen
studded with cones
throughout the year, and clusters of leaves
may be seen sprouting directly
from the trunk of the tree; see
Fig. 5. The last two
are very characteristic and will distinguish
the tree at a glance.
Form and size: It is a low tree of uncertain
habit and extremely rough
looking at every stage of
its life. It is constantly full of dead
branches and old cones which
persist on the tree throughout the
year.
Range: Eastern United States.
Soil and location: Grows in the poorest and sandiest
soils where few
other trees will grow.
In New Jersey and on Long Island where it is
native, it proves so hardy
and persistent that it often forms pure
stands excluding other trees.
[Illustration: FIG. 4.—Twig of the Pitch Pine.]
Enemies: None of importance.
Value for planting: Well adapted for the sea
coast and other exposed
places. It is of extremely
uncertain habit and is subject to the
loss of the lower limbs.
It frequently presents a certain
picturesqueness of outline,
but it could not be used as a specimen
tree on the lawn.
[Illustration: FIG. 5.—The Pitch Pine.]
Commercial value: The wood is coarse grained
and is used for rough
lumber, fuel, and charcoal.
Other characters: The fruit is a cone
one to three
inches long, persistent on the tree for several years.
Distinguishing characters: There are two
needles to each cluster, and
these are short compared
with those of the white pine, and
slightly twisted; see
Fig. 6. The bark, especially along the
upper portion of the trunk,
is reddish in color.
Form and size: A medium-sized tree with a short crown.
Range: Europe, Asia, and eastern United States.
Soil and location: Will do best on a deep, rich,
sandy soil, but will
also grow on a dry, porous
soil.
Enemies: In Europe the Scotch pine has several
insect enemies, but in
America it appears to be free
from injury.
Value for planting: Suitable for windbreaks and
woodland planting. Many
excellent specimens may also
be found in our parks.
Commercial value: In the United States, the wood
is chiefly used for
fuel, though slightly used
for barrels, boxes, and carpentry. In
Europe, the Scotch pine is
an important timber tree.
Comparisons: The Scotch pine is apt to be confused
with the Austrian
pine (Pinus austriaca),
because they both have two needles to
each cluster. The needles
of the Austrian pine, however, are much
longer, coarser, straighter,
and darker than those of the Scotch
pine; Fig. 1. The form
of the Austrian pine, too, is more
symmetrical and compact.
[Illustration: FIG. 6.—Twig of the Scotch Pine.]
The red pine (Pinus resinosa) is another tree that has two needles to each cluster, but these are much longer than those of the Scotch pine (five to six inches) and are straighter. The bark, which is reddish in color, also differentiates the red pine from the Austrian pine. The position of the cones on the red pine, which point outward and downward at maturity, will also help to distinguish this tree from the Scotch and the Austrian varieties.
How to tell them from other trees: The spruce
and hemlock belong to the
evergreen class and may be
told from the other trees by their
leaves. The characteristic
leaves of the spruce are shown in Fig.
9; those of the hemlock in
Fig. 10. These are much shorter than the
needles of the pines but are
longer than the leaves of the red cedar
or arbor vitae. They
are neither arranged in clusters like those of
the larch, nor in feathery
layers like those of the cypress. They
adhere to the tree throughout
the year, while the leaves of the
larch and cypress shed in
the fall.
The spruces are pyramidal-shaped trees, with tall and tapering trunks, thickly covered with branches, forming a compact crown. They are widely distributed throughout the cold and temperate regions of the northern hemisphere, where they often form thick forests over extended areas.
There are eighteen recognized
species of spruce. The Norway spruce
has been chosen as a type
for this group because it is so commonly
planted in the northeastern
part of the United States.
The hemlock is represented
by seven species, confined to temperate
North America, Japan, and
Central and Western China.
[Illustration: FIG. 7.—The Norway Spruce.]
How to tell them from each other: The needles
and branches of the spruce
are coarse; those of
the hemlock are flat and graceful. The
individual leaves of the spruce,
Fig. 9, are four-sided and green or
blue on the under side, while
those of the hemlock, Fig. 10, are
flat and are marked by
two white lines on the under side.
Distinguishing characters: The characteristic
appearance of the
full-grown tree is due to
the drooping branchlets carried on main
branches which bend upward
(Fig. 7).
Leaf: The leaves are dark green in color and
are arranged spirally,
thus making the twigs coarser
to the touch than the twigs of the
hemlock or fir. In cross-section,
the individual leaflet is
quadrilateral, while that
of the pine is triangular.
Form and size: A large tree with a straight,
undivided trunk and a
well-shaped, conical crown
(Fig. 7).
Range: Northern Europe, Asia, northern North America.
Soil and location: Grows in cool, moist situations.
Enemies: The foliage of the spruce is sometimes
affected by red
spider, but is apt to
be more seriously injured by drought, wind,
and late frosts.
Value for planting: Commonly planted as an ornamental
tree and for
hedges. It does well
for this purpose in a cool northern climate,
but in the vicinity of New
York City and further south it does not
do as well, losing its lower
branches at an early age, and becoming
generally scraggly in appearance.
[Illustration: FIG. 8.—A Group of Hemlock.]
Commercial value: The wood is light and soft
and is used for
construction timber, paper
pulp, and fuel.
Other characters: The fruit is a large
slender cone, four to seven
inches long.
Comparisons: The white spruce (Picea
canadensis) may be told from
the Norway spruce by the whitish
color on the under side of its
leaves and the unpleasant,
pungent odor emitted from the needles
when bruised. The cones
of the white spruce, about two inches long,
are shorter than these of
the Norway spruce, but are longer than
those of the black spruce.
It is essentially a northern tree growing in all sorts of locations along the streams and on rocky mountain slopes as far north as the Arctic Sea and Alaska. It often appears as an ornamental tree as far south as New York and Pennsylvania.
The black spruce (Picea mariana) may be told from the other spruces by its small cone, which is usually only about one inch in length. In New England it seldom grows to as large a size as the other spruce trees.
It covers large areas in various
parts of northern North America and
grows to its largest size
in Manitoba. The black spruce has little
value as an ornamental tree.
The Colorado blue spruce (Picea parryana or Picea pungens) which is commonly used as an ornamental tree on lawns and in parks, can be told from the other spruces by its pale-blue or sage-green color and its sharp-pointed, coarse-feeling twigs. Its small size and sharp-pointed conical form are also characteristic.
It grows to a large size in
Colorado and the Middle West. In the
Eastern States and in northern
Europe where it is planted as an
ornamental tree, it is usually
much smaller.
[Illustration: FIG. 9.—Twig of the Norway Spruce.]
Distinguishing characters: Its leaves are arranged
in flat layers,
giving a flat, horizontal
and graceful appearance to the whole
branch (Fig. 8). The
individual leaves are dark green above, lighter
colored below, and are marked
by two white lines on the under side
(Fig. 10).
The leaves are arranged on
little stalks, a characteristic that does
not appear in the other evergreen
trees.
Form and size: A large tree with a broad-based
pyramidal head, and a
trunk conspicuously tapering
toward the apex. The branches extend
almost to the ground.
Range: The hemlock is a northern tree, growing
in Canada and the United
States.
Soil and location: Grows on all sorts of soils,
in the deepest woods as
well as on high mountain slopes.
Enemies: None of importance.
Value for planting: The hemlock makes an excellent
hedge because it
retains its lowest branches
and will stand shearing. In this respect
it is preferable to the spruce.
It makes a fair tree for the lawn
and is especially desirable
for underplanting in woodlands, where
the shade from the surrounding
trees is heavy. In this respect it is
like the beech.
Commercial value: The wood is soft, brittle,
and coarse-grained, and is
therefore used mainly for
coarse lumber. Its bark is so rich in
tannin that it forms one of
the chief commercial products of the
tree.
Other characters: The fruit is a small
cone about 3/4 of an inch long,
which generally hangs on the
tree all winter.
[Illustration: FIG. 10.—Twig of the Hemlock.]
How to tell them from other trees: The red cedar
(juniper) and
arbor-vitae may be told from
other trees by their leaves, which
remain on the tree and keep
green throughout the entire year. These
leaves differ from those of
the other evergreens in being much
shorter and of a distinctive
shape as shown in Figs. 12 and 13. The
trees themselves are much
smaller than the other evergreens
enumerated in this book.
Altogether, there are thirty-five species
of juniper recognized and
four of arbor-vitae. The junipers are
widely distributed over the
northern hemisphere, from the Arctic
region down to Mexico in the
New World, and in northern Africa,
China, and Japan in the Old
World. The arbor-vitae is found in
northeastern and northwestern
America, China, and Japan. The species
mentioned here are those commonly
found in America.
How to tell them from each other: The twigs
of the arbor-vitae are
flat and fan-like as
in Fig. 13; the twigs of the red cedar are
needle-shaped or scale-like
as in Fig. 12. The foliage of the
arbor-vitae is of a lighter
color than that of the red cedar, which
is sombre green. The
arbor-vitae will generally be found growing in
moist locations, while the
red cedar will grow in dry places as
well. The arbor-vitae
generally retains its lower branches in open
places, while the branches
of the red cedar start at some distance
from the ground.
[Illustration: FIG. 11.—The Red Cedar.]
Distinguishing characters: The tree can best
be told at a glance by its
general form, size and leaves.
It is a medium-sized tree with a
symmetrical, cone-like
form, Fig. 11, which, however, broadens
out somewhat when the tree
grows old. Its color throughout the year
is dull green with a tinge
of brownish red, and its bark peels in
thin strips.
[Illustration:
FIG. 12(a).—Twig of Young Cedar.
FIG. 12(b).—Twig of Cedar (Older Tree).]
Leaf: In young trees the leaf is needle-shaped,
pointed, and marked by a
white line on its under side,
Fig. 12(a). In older trees it is
scale-like, Fig. 12(b), and
the white line on its under side is
indistinct.
Range: Widely distributed over nearly all of
eastern and central North
America.
Soil and location: Grows on poor, gravelly soils
as well as in rich
bottom lands.
Enemies: The “cedar apple,”
commonly found on this tree, represents a
stage of the apple rust, and
for that reason it is not desirable to
plant such trees near orchards.
Its wood is also sometimes attacked
by small boring insects.
Value for planting: Its characteristic slender
form gives the red cedar
an important place as an ornamental
tree, but its chief value lies
in its commercial use.
Commercial value: The wood is durable, light,
smooth and fragrant, and
is therefore used for making
lead-pencils, cabinets, boxes,
moth-proof chests, shingles,
posts, and telegraph poles.
Other characters: The fruit is small,
round and berry-like, about the
size of a pea, of dark blue
color, and carries from one to four bony
seeds.
Other common names: The red cedar is also often
called juniper and
red juniper.
Comparisons: The red cedar is apt to be confused
with the low juniper
(Juniperus communis)
which grows in open fields all over the
world. The latter, however,
is generally of a low form with a flat
top. Its leaves are pointed
and prickly, never scale-like, and they
are whitish above and green
below. Its bark shreds and its fruit is
a small round berry of agreeable
aromatic odor.
Distinguishing characters: The branchlets
are extremely flat and
fan-like, Fig. 13, and
have an agreeable aromatic odor when
bruised. The tree is
an evergreen with a narrow conical form.
[Illustration: FIG. 13.—Twig of the Arbor-vitae.]
Leaf: Leaves of two kinds, one scale-like and
flat, the other keeled,
all tightly pressed to the
twig (see Fig. 13).
Form and size: A close, conical head with dense
foliage near the base.
Usually a small tree, but
in some parts of the northeastern States
it grows to medium size with
a diameter of two feet.
Range: Northern part of North America.
Soil and location: Inhabits low, swampy lands;
in the State of Maine
often forming thick forests.
Enemies: Very seldom affected by insects.
Value for planting: Is hardy in New England,
where it is especially used
for hedges. It is also
frequently used as a specimen tree on the
lawn.
Commercial value: The wood is durable for posts,
ties, and shingles. The
bark contains considerable
tannin and the juices from the tree have
a medicinal value.
Other characters: The fruit is a cone about 1/2 inch long.
Other common names: Arbor-vitae is sometimes
called white cedar and
cedar.
Comparisons: The arbor-vitae is apt to be confused
with the true white
cedar (Chamaecyparis
thyoides) but the leaves of the latter are
sharp-pointed and not flattened
or fan-shaped.
HOW TO IDENTIFY TREES—(Continued)
How to tell them from other trees: In summer
the larch and cypress may
easily be told from other
trees by their leaves. These are
needle-shaped and arranged
in clusters with numerous leaves to each
cluster in the case of the
larch, and feathery and flat in the case
of the cypress. In winter,
when their leaves have dropped off, the
trees can be told by their
cones, which adhere to the branches.
There are nine recognized species of larch and two of bald cypress. The larch is characteristically a northern tree, growing in the northern and mountainous regions of the northern hemisphere from the Arctic circle to Pennsylvania in the New World, and in Central Europe, Asia, and Japan in the Old World. It forms large forests in the Alps of Switzerland and France.
The European larch and not
the American is the principal species
considered here, because it
is being planted extensively in this
country and in most respects
is preferable to the American species.
The bald cypress is a southern tree of ancient origin, the well-known cypress of Montezuma in the gardens of Chepultepec having been a species of Taxodium. The tree is now confined to the swamps and river banks of the South Atlantic and Gulf States, where it often forms extensive forests to the exclusion of all other trees. In those regions along the river swamps, the trees are often submerged for several months of the year.
How to tell them from each other: In summer the
larch may be told from
the cypress by its leaves
(compare Figs. 14 and 16). In winter the
two can be distinguished by
their characteristic forms. The larch is
a broader tree as compared
with the cypress and its form is more
conical. The cypress
is more slender and it is taller. The two have
been grouped together in this
study because they are both coniferous
trees and, unlike the other
Conifers, are both deciduous, their
leaves falling in October.
[Illustration: FIG. 14.—Twig of the Larch in Summer.]
Distinguishing characters: Its leaves, which
are needle-shaped and about
an inch long, are borne in
clusters close to the twig, Fig. 14.
There are many leaves to each
cluster. This characteristic together
with the spire-like
form of the crown will distinguish the tree at
a glance.
Leaf: The leaves are of a light-green color but
become darker in the
spring and in October turn
yellow and drop off. The cypress, which
is described below, is another
cone-bearing tree which sheds its
leaves in winter.
[Illustration: FIG. 15.—Twig of the Larch in Winter.]
Form and size: A medium-sized tree with a conical
head and a straight
and tapering trunk. (See Fig.
90.)
Range: Central Europe and eastern and central United States.
Soil and location: Requires a deep, fresh, well-drained
soil and needs
plenty of light. It flourishes
in places where our native species
would die. Grows very
rapidly.
Enemies: The larch is subject to the attacks
of a sawfly, which has
killed many trees of the American
species. A fungus (Trametes
pini) which causes the
tree to break down with ease is another of
its enemies.
Value for planting: A well-formed tree for the
lawn. It is also useful
for group planting in the
forest.
Commercial value: Because its wood is strong
and durable the larch is
valuable for poles, posts,
railroad ties, and in shipbuilding.
[Illustration: FIG. 16.—Twig of the Cypress.]
Other characters: The fruit is a small
cone about one inch long,
adhering to the tree throughout
the winter.
[Illustration: FIG. 17.—The Bald Cypress.]
Comparisons: The tree is apt to be confused with
the American larch,
also known as tamarack
and hackmatack, but differs from it in
having longer leaves, cones
twice as large and more abundant and
branches which are more pendulous.
The larch differs from the bald cypress in the broader form of its crown and the cluster-like arrangement of its leaves. The twigs of the bald cypress are flat and feathery. The larch and bald cypress have the common characteristics of both shedding their leaves in winter and preferring to grow in moist or swampy soils. The larch, especially the native species, forms the well-known tamarack swamps of the north. The bald cypress grows in a similar way in groups in the southern swamps.
Distinguishing characters: The feathery character
of the twigs, Fig.
16, and the spire-like
form of the tree, Fig. 17, which is taller
and more slender than the
larch, will distinguish this species from
others.
[Illustration: FIG. 18.—Cypress “Knees.”]
Leaf: The leaves drop off in October, though
the tree is of the
cone-bearing kind. In
this respect it is like the larch.
Form and size: Tall and pyramidal.
Range: The cypress is a southern tree, but is
found under cultivation in
parks and on lawns in northern
United States.
Soil and location: Grows naturally in swamps,
but will also do well in
ordinary well-drained, good
soil. In its natural habitat it sends
out special roots above water.
These are known as “cypress knees”
(Fig. 18) and serve to provide
air to the submerged roots of the
tree.
Enemies: None of importance.
Value for planting: An excellent tree for park and lawn planting.
Commercial value: The wood is light, soft, and
easily worked. It is used
for general construction,
interior finish, railroad ties, posts and
cooperage.
Other characters: The bark is thin and
scaly. The fruit is a cone
about an inch in diameter.
The general color of the tree is a
dull, deep green which, however,
turns orange brown in the fall.
Comparisons: The cypress and the larch are apt
to be confused,
especially in the winter,
when the leaves of both have dropped. The
cypress is more slender and
is taller in form. The leaves of each
are very different, as will
be seen from the accompanying
illustrations.
How to tell them from other trees: The horsechestnut,
ash, and maple
have their branches and buds
arranged on their stems opposite each
other as shown in Figs. 20,
22 and 24. In other trees, this
arrangement is alternate,
as shown in Fig. 19.
How to tell these three from each other. If the
bud is large—an inch to
an inch and a half long—dark
brown, and sticky, it is a
horsechestnut.
If the bud is not sticky,
much smaller, and rusty brown to black
in color, and the ultimate
twigs, of an olive green color, are
flattened at points
below the buds, it is an ash.
[Illustration: FIG. 19.—Alternate Branching (Beech.)]
If it is not a horsechestnut nor an ash and its small buds have many scales covering them, the specimen with branches and buds opposite must then be a maple. Each of the maples has one character which distinguishes it from all the other maples. For the sugar maple, this distinguishing character is the sharp point of the bud. For the silver maple it is the bend in the terminal twig. For the red maple it is the smooth gray-colored bark. For the Norway maple it is the reddish brown color of the full, round bud, and for the box elder it is the greenish color of its terminal twig.
The form of the tree and the leaves are also characteristic in each of the maples, but for the beginner who does not wish to be burdened with too many of these facts at one time, those just enumerated will be found most certain and most easily followed.
[Illustration: FIG. 20.—Opposite Branching (Horsechestnut.)]
THE HORSECHESTNUT (Aesculus hippocastanum)
Distinguishing characters: The sticky
nature of the terminal bud and
its large size (about
an inch long). The bud is dark brown in
color. See Fig. 20.
Leaf: Five to seven leaflets, usually seven. Fig. 21.
Form and size: Medium-sized tree, pyramidal head and coarse twigs.
Range: Europe and eastern United States.
Soil and location: Prefers a deep, rich soil.
Enemies: The leaves are the favorite food of
caterpillars and are
subject to a blight which
turns them brown prematurely. The trunk is
often attacked by a disease
which causes the flow of a slimy
substance.
Value for planting: On account of its showy flowers,
the horsechestnut
is a favorite for the park
and lawn.
Commercial value: The wood is not durable and is not used commercially.
Other characters: The flowers appear in
large white clusters in May
and June. The fruit
is large, round, and prickly.
[Illustration: FIG. 21.—Leaf of the Horsechestnut.]
Comparisons: The red horsechestnut differs
from this tree in having
red flowers. The buckeye
is similar to the horsechestnut, but its
bud is not sticky and is of
a lighter gray color, while the leaf
generally has only five leaflets.
Distinguishing characters: The terminal twigs
of glossy olive green
color are flattened
below the bud. Fig. 22. The bud is
rusty-brown.
[Illustration: FIG. 22.—Twig of White Ash.]
Leaf: Five to nine leaflets. Fig. 23.
Form and size: A large tree with a straight trunk.
Range: Eastern North America.
Soil and location: Rich, moist soil.
Enemies: In cities it is very often attacked by sucking insects.
Value for planting: The white ash grows rapidly.
On account of its
insect enemies in cities,
it should be used more for forest planting
and only occasionally for
ornament.
Commercial value: It has a heavy, tough, and
strong wood, which is
valuable in the manufacture
of cooperage stock, agricultural
implements, and carriages.
It is superior in value to the black ash.
Other characters: The bark is gray. The flowers appear in May.
Comparisons: The white ash is apt to be confused
with the black ash
(Fraxinus nigra), but
differs from the latter in having a
lighter-colored bud.
The bud of the black ash is black. The bark of
the white ash is darker in
color and the terminal twigs are more
flattened than those of the
black ash.
[Illustration: FIG. 23.—Leaf of White Ash.]
Distinguishing characters: The bud is sharp-pointed,
scaly, and
reddish brown. Fig. 24.
[Illustration: FIG. 24.—Twig of the Sugar Maple.]
Leaf: Has sharp points and round sinus. Fig. 25.
Form and size: The crown is oval when the tree
is young and round in old
age. Fig. 26.
Range: Eastern United States.
Soil and location: Moist and deep soil, and cool, shady positions.
Enemies: Subject to drouth, especially in cities.
Is attacked by the
sugar maple borer and
the maple phenacoccus, a sucking insect.
Value for planting: Its rich and yellow color
in the fall, and the fine
spread of its crown make it
a desirable tree for the lawn,
especially in the country.
Commercial value: Its wood is hard and takes
a good polish; used for
interior finish and furniture.
The tree is also the source of maple
sugar. Fig. 27.
Other characters: The bark is smooth in
young trees and in old trees
it shags in large plates.
The flowers appear in the early part of
April.
Other common names: The sugar maple is sometimes
called rock maple or
hard maple.
Distinguishing characters: The tips of the twigs
curve upwards (Fig.
28), the bark is scaly, and
the leaves are very deeply cleft and are
silvery on the under side.
[Illustration: FIG. 25.—Leaf of Sugar Maple.]
Leaf: Deeply cleft and silvery under side. Fig. 29.
Form and size: A large tree with the main branches
separating from the
trunk a few feet from the
ground. The terminal twigs are long,
slender, and drooping.
Range: Eastern United States.
Soil and location: Moist places.
Enemies: The leopard moth, a wood-boring
insect, and the
cottony-maple scale,
a sucking insect.
[Illustration: FIG. 26.—The Sugar Maple.]
Value for planting: Grows too rapidly and is
too short-lived to be
durable.
Commercial value: Its wood is soft, weak, and little used.
Other characters: The bark is light gray,
smooth at first and scaly
later on. The scales
are free at each end and attached in the
center. The flowers
appear before the leaves in the latter part of
March or early April.
[Illustration: FIG. 27.—Tapping the Sugar Maple.]
Other common names: The silver maple is sometimes
known as soft maple
or white maple.
[Illustration: FIG. 28.—Terminal Twig of Silver Maple.]
Distinguishing characters: The bark is smooth
and light gray, like
that of the beech, on the
upper branches in older trees, and in
young trees over the whole
trunk. Fig. 30. The buds are in clusters,
and the terminal twigs, Fig.
31, are quite red.
[Illustration: FIG. 29.—Leaf of the Silver Maple.]
Leaf: Whitish underneath with three-pointed lobes. Fig. 32.
Form and size: A medium-sized tree with a narrow, round head.
Range: Eastern North America.
Soil and location: Prefers moist places.
Enemies: Leaf blotches (Rhytisma acerinum)
which, however, are not
very injurious.
Value for planting: Suitable as a shade tree
for suburban streets. Its
rich red leaves in the fall
make it attractive for the lawn.
[Illustration: FIG. 30.—Bark of the Red Maple.]
Commercial value: Its wood is heavy, close-grained,
and takes a good
polish. Used for furniture
and fuel.
Other characters: The bud is small, round,
and red. The flowers
appear before the leaves are
out in the early part of April.
[Illustration: FIG. 31.—Twig of the Red Maple.]
[Illustration: FIG. 32.—Leaf of the Red Maple.]
Other common names: The red maple is sometimes known as swamp maple.
[Illustration: FIG. 33.—Twig of Norway Maple.]
Comparisons: The red maple is apt to be confused
with the silver maple,
but the latter can be distinguished
by its turned-up twigs and scaly
bark over the whole trunk
of the tree, which presents a sharp
contrast to the straight twig
and smooth bark of the red maple. The
latter has a bark similar
to the beech, but its branches are
opposite, while those
of the beech are alternate.
Distinguishing characters: The bud, Fig. 33,
is oval and reddish-brown
in color; when taken off,
a milky juice exudes. The bark is close.
Fig. 34
[Illustration: FIG. 34.—Bark of Norway Maple.]
Leaf: Like the leaf of the sugar maple but thicker
in texture and darker
in color. Fig. 35.
Form and size: A tall tree with a broad, round head.
Range: Europe and the United States.
Soil and location: Will grow in poor soil.
Enemies: Very few.
Value for planting: One of the best shade trees.
Commercial value: None.
Other characters: The bark is close like
that of the mockernut
hickory.
Comparisons: The Norway maple is apt to be confused
with the sycamore
maple (Acer pseudoplatanus),
but differs from the latter in
having a reddish bud instead
of a green bud, and a close bark
instead of a scaly bark.
Distinguishing characters: The terminal twigs
are green, and the buds
are round and small.
Fig. 36.
Leaf: Has three to seven leaflets.
[Illustration: FIG. 35.—Leaf of Norway Maple.]
Form and size: A medium-sized tree with a short
trunk and wide-spreading
top.
Range: Eastern United States to the Rocky Mountains.
Soil and location: Grows rapidly in deep, moist
soil and river valleys,
but accommodates itself to
the dry and poor soil conditions of the
city.
[Illustration: Figure 36.—Twig of the Box Elder.]
Enemies: Few.
Value for planting: Used as a shade tree in the
Middle West, but the
tree is so ill formed and
so short-lived that it is not to be
recommended.
Commercial value: None. The wood is soft.
Other characters: The bark of the trunk
is smooth and yellowish-green
in young trees and grayish
brown in older specimens. The flowers
appear in the early part of
April. The fruit takes the form of
yellowish-green keys which
hang on the tree till late fall.
Other common names: The box elder is also commonly
known as the
ash-leaf maple.
How to tell them from other trees: The trees
described in this group are
so distinctive in their general
form that they may, for the
purpose of study, be grouped
together, and distinguished from all
other trees by this characteristic.
How to tell them from each other: The American
elm is vase-like in
shape; the Lombardy poplar
is narrow and spire-like; the gingko,
or maidenhair tree, is odd
in its mode of branching; and the
weeping willow is extremely
pendulous.
Distinguishing characters: The tree can be told
at a glance by its
general branching habit.
The limbs arch out into a wide-spreading
fan or vase-like crown
which loses itself in numerous fine
drooping branchlets.
See Fig. 37.
[Illustration: FIG. 37.—American Elm.]
Leaf: The leaves are simple, alternate, and from 2 to 5 inches long.
[Illustration: FIG. 38.—English Elm in Winter.]
Form and size: It is a tall tree with a trunk
that divides a short
distance above ground.
Its general contour, together with the
numerous branches that interlace
its massive crown, give the elm an
interesting and stately appearance
which is unequaled by any other
tree.
[Illustration: FIG. 39.—Lombardy Poplar.]
Range: Eastern North America.
Soil and location: The elm prefers a deep, rich
and moist soil, but will
adapt itself even to the poor
soil of the city street.
Enemies: The leopard moth, a wood-boring
insect, and the elm leaf
beetle, a leaf-eating
insect, are the two most important enemies of
the tree. Their ravages
are very extensive.
Value for planting: The tree has a character
of its own which cannot be
duplicated for avenue or lawn
planting.
Commercial value: The wood is strong and tough
and therefore has a
special value for cooperage,
agricultural implements, carriages, and
shipbuilding.
Other characters: The buds are small,
brown, and smooth, while those
of the European elms are covered
with down. The small side twigs
come out at almost right angles
to the larger terminal twigs, which
is not the case in other species
of elm.
[Illustration: FIG. 40.—Leaf of Carolina Poplar.]
Other common names: White elm.
Comparisons: The English elm (Ulmus
campestris) is also a tall,
dignified tree commonly seen
under cultivation in America, but may
be told from the American
species by the difference in their general
contour. The branches
of the English species spread out but do not
arch like those of the American
elm, and the bark of the English elm
is darker and coarser, Fig.
38. Little tufts of dead twigs along the
main branches and trunk of
the tree are characteristic of the
English elm and will frequently
help to distinguish it from the
American elm.
The Camperdown elm
may be recognized readily by its dwarf size and
its low drooping umbrella-shaped
crown.
LOMBARDY OR ITALIAN POPLAR (Populus nigra, var. italica)
Distinguishing characters: Its tall, slender,
spire-like form and
rigidly erect branches,
which commence low on the trunk, make this
tree very distinct at all
seasons of the year. See Fig. 39.
Leaf: Triangular in shape, similar to that of
the Carolina poplar but
smaller, see Fig. 40.
Range: Asia, Europe, and North America.
Soil and location: The poplar is easily grown
in poor soil, in any
location, and is very hardy.
Value for planting: The tree has a distinctive
form which makes it
valuable for special landscape
effects. It is also used for shelter
belts and screening.
Like all poplars it is short lived and will
stand pruning well.
Commercial value: None.
[Illustration: FIG. 41.—Carolina Poplar.]
Comparisons: The Carolina poplar, or Cottonwood
(Populus deltoides)
can be told from the Lombardy
poplar by its wider crown and its more
open branching, Fig. 41.
It may be recognized by its big terminal
twigs, which are light yellow
in color and coarser than those of the
Lombardy poplar, Fig. 42.
Its bark is smooth, light and
yellowish-green in young trees,
and dark gray and fissured in older
specimens. Its large,
conical, glossy, chestnut-brown bud is also
characteristic, Fig. 42.
Its flowers, in the form of large catkins,
a peculiarity of all poplars,
appear in the early spring. The
Carolina poplar is commonly
planted in cities because it grows
rapidly and is able to withstand
the smoke and drouth conditions of
the city. Where other
trees, however, can be substituted with
success, the poplar should
be avoided. Its very fast growth is
really a point against the
tree, because it grows so fast that it
becomes too tall for surrounding
property, and its wood being
extremely soft and brittle,
the tree frequently breaks in
windstorms. In many cases
it is entirely uprooted, because it is not
a deep-rooted tree. Its
[Illustration: FIG. 42.—Bud of the Carolina Poplar.]
The silver or white poplar (Populus alba) may be told from the other poplars by its characteristic smooth, whitish-green bark, often spotted with dark blotches, Fig. 43. The leaves are silvery-white and downy on the under side. The twigs are dark green in color and densely covered with a white down. It grows to very large size and forms an irregular, wide-spreading, broad head, which is characteristically different from that of any of the other poplars.
[Illustration: FIG. 43.—Bark of the Silver Poplar.]
The quaking aspen (Populus tremuloides), the large-toothed aspen (Populus grandidentata) and the balsam poplar or balm of Gilead (Populus balsamifera) are other common members of the poplar group. The quaking aspen may be told by its reddish-brown twigs, narrow sharp-pointed buds, and by its small finely toothed leaves. The large-toothed aspen has thicker and rather downy buds and broader and more widely toothed leaves. The balsam poplar has a large bud thickly covered with a sticky, pungent, gelatinous substance.
GINGKO OR MAIDENHAIR TREE (Gingko biloba)
[Illustration: FIG. 44.—Gingko Trees.]
Distinguishing characters: The peculiar branches
of this tree emerge
upward from a straight
tapering trunk at an angle of about 45 deg.
and give to the whole tree
a striking, Oriental appearance, which is
quite different from that
of any other tree, Fig. 44.
Leaf: Like that of a leaflet of maidenhair fern, Fig. 45.
Range: A native of northern China and introduced
into eastern North
America.
Soil and location: The gingko will grow in poor soils.
Enemies: Practically free from insects and disease.
[Illustration: FIG. 45.—Leaves of the Gingko Tree.]
Value for planting: It makes a valuable tree
for the street where heavy
shade is not the object and
forms an excellent wide-spreading
specimen tree on the lawn.
Other characters: The fruit consists of
a stone covered by sweet,
ill-smelling flesh. The
tree is dioecious, there being separate male
and female trees. The
male tree is preferable for planting in order
to avoid the disagreeable
odor of the fruit which appears on the
female trees when about thirty
years old. The male tree has a
narrower crown than the female
tree. The buds (Fig. 46) are very odd
and are conspicuous on the
tree throughout the winter. The leaves of
the gingko shed in the winter.
In this respect the tree is like the
larch and the bald cypress.
[Illustration: FIG. 46.—Bud of the Gingko Tree.]
The gingko belongs to the yew family, which is akin to the pine family. It is therefore a very old tree, the remains of the forests of the ancient world. The gingko in its early life is tall and slender with its few branches close to the stem. But after a time the branches loosen up and form a wide-spreading crown. In the Orient it attains enormous proportions and in this country it also grows to a fairly large size when planted on the open lawn or in groups far apart from other trees so that it can have plenty of room to spread. It then produces a picturesque effect of unusual interest.
Distinguishing characters: All the willows have
a single cap-like scale
to the bud, and this species
has an unusually drooping mass of
slender branchlets which
characterizes the tree from all others,
Fig. 47.
[Illustration: FIG. 47.—Weeping Willow.]
Form and size: It grows to large size.
Range: Asia and Europe and naturalized in eastern United States.
Soil and location: Prefers moist places near streams and ponds.
Enemies: None of importance.
Value for planting: The weeping willow has a
special ornamental effect
in cemeteries and along lakes
and river banks in parks.
Commercial value: It is used in the United States
for charcoal and for
fuel.
Comparisons: The pussy willow (Salix
discolor) may easily be told
from the other willows by
its small size; it is often no higher than
a tall shrub. Its branches
are reddish green and the buds are dark
red, smooth and glossy.
The predominating color of the twigs and
buds in the pussy willow is
therefore a shade of red, while in the
weeping willow it is yellowish
green.
GROUP VII. TREES TOLD BY THEIR BARK OR TRUNK: SYCAMORE, BIRCH, BEECH, BLUE BEECH, IRONWOOD, AND HACKBERRY
How to tell them from other trees: The color
of the bark or the form of
the trunk of each of the
trees in this group is distinct from that
of any other tree.
How to tell them from each other: In the sycamore,
the bark is
mottled; in the white
birch, it is dull white; in the beech, it
is smooth and gray;
in the hackberry, it is covered with numerous
corky warts; in the
blue beech, the trunk of the tree is fluted,
as in Fig. 54, and in the
ironwood, the bark peels in thin
perpendicular strips.
[Illustration: FIG. 48.—Bark of the Sycamore Tree.]
THE SYCAMORE OR PLANE TREE (Platanus occidentalis)
Distinguishing characters: The peculiar mottled
appearance of the
bark (Fig. 48) in the
trunk and large branches is the striking
character here. The bark
produces this effect by shedding in large,
thin, brittle plates.
The newly exposed bark is of a yellowish green
color which often turns nearly
white later on. Round seed balls,
about an inch in diameter,
may be seen hanging on the tree all
winter. In this species,
the seed balls are usually solitary, while
in the Oriental sycamore,
a European tree similar to the native one,
they appear in clusters of
two, or occasionally of three or four.
See Fig. 49.
[Illustration: FIG. 49.—Seed-balls of the Oriental Sycamore. Note one Seed-ball cut in half.]
[Illustration: FIG. 50.—Gray or White Birch Trees.]
Leaf: The stem of the leaf completely covers
the bud. This is a
characteristic peculiar to
sycamores.
Form and size: A large tree with massive trunk
and branches and a broad
head.
Range: Eastern and southern United States.
Soil and location: Prefers a deep rich soil,
but will adapt itself even
to the poor soil of the city
street.
Enemies: The sycamore is frequently attacked
by a fungus (Gloeosporium
nervisequum), which curls
up the young leaves and kills the tips of
the branches. Late frosts
also often injure its young twigs. The
Oriental sycamore, which is
the European species, is more hardy in
these respects than the native
one and is therefore often chosen as
a substitute.
Value for planting: The Occidental sycamore is
now planted very little,
but the Oriental sycamore
is used quite extensively in its place,
especially as a shade tree.
The Oriental sycamore is superior to the
native species in many ways.
It is more shapely, faster growing, and
hardier than the native one.
Both sycamores will bear transplanting
and pruning well.
[Illustration: FIG. 51.—Bark of the Black or Sweet Birch.]
Commercial value: The wood of the sycamore is
coarse-grained and hard to
work; used occasionally for
inside finishing in buildings.
Other names: Buttonball, buttonwood.
Comparisons: The Oriental sycamore (Platanus
orientalis) an
introduced species, is apt
to be confused with the Occidental
sycamore, but may be told
from the latter by the number of seed
balls suspended from the tree.
In the case of the Oriental species,
the seed balls hang in pairs
or (rarely) three or four together.
In the Occidental, the seed
balls are generally solitary and very
rarely in pairs.
GRAY OR WHITE BIRCH (Betula populifolia)
Distinguishing characters: The dull-white
color of the bark on the
trunk and the dark triangular
patches below the insertion of the
branches distinguish this
tree; see Fig. 50. The bark of the young
trunks and branches is reddish-brown
in color and glossy. The bark
adheres closely to the trunk
of the tree and does not peel in loose,
shaggy strips, as in the case
of the yellow or golden birch. It is
marked by small raised horizontal
lines which are the lenticels or
breathing pores. These
lenticels are characteristic of all birch and
cherry trees. In addition
to the distinction in the color of the
bark, an important character
which distinguishes the gray birch from
all other species of birch,
is found in the terminal twigs, which
are rough to the touch.
Form and size: A small tree. Frequently grows in clumps.
Range: Eastern United States.
Soil and location: The gray birch does best in
a deep, rich soil, but
will also grow in poor soils.
Enemies: The bronze-birch borer, a wood-destroying
insect, and
Polyporus betulinus,
a fungus, are its chief enemies.
Value for planting: Its graceful habit and attractive
bark gives the
tree an important place in
ornamental planting. It may be used to
advantage with evergreens,
and produces a charming effect when
planted by itself in clumps.
[Illustration: FIG. 52.—Bark of the Beech.]
[Illustration: FIG. 53.—Buds of the Beech Tree.]
Commercial value: The wood is soft and not durable.
It is used in the
manufacture of small articles
and for wood pulp.
Other characters: The fruit is a catkin.
Comparisons: The paper birch (Betula
papyrifera) is apt to be
confused with the gray birch,
because both have a white bark. The
bark of the paper birch, however,
is a clear white and peels off in
thin papery layers instead
of being close. It very seldom shows any
dark triangular markings on
the trunk. Its terminal twigs are not
rough and its trunk is usually
straighter and freer from branches.
The black or sweet
birch (Betula lenta) has a bark similar
to
the gray birch, except that
its color is dark gray. See Fig. 51. The
twigs have an aromatic taste.
[Illustration: FIG. 54.—Trunk of Blue Beech.]
[Illustration: FIG. 55.—Bark of the Ironwood.]
The yellow birch (Betula
lutea) has a yellowish or golden bark
which constantly peels in
thin, ragged, horizontal films.
The European white birch (Betula alba) has a dull-white bark like the native white birch, but has smooth terminal twigs instead of rough ones. It is commonly seen in the United States on lawns and in parks.
Distinguishing characters: The close-fitting,
smooth, gray bark will
tell this tree from all others
except the red maple and yellow-wood.
See Fig. 52. The red
maple may then be easily eliminated by noting
whether the branches are alternate
or opposite. They are alternate
in the beech and opposite
in the maple. The yellow-wood may be
eliminated by noting the size
of the bud. The bud in the
yellow-wood is hardly noticeable
and of a golden yellow color, while
that of the beech is very
long, slender, and sharp-pointed, and
chestnut brown in color.
See Fig. 53.
Form and size: It grows tall in the woods, but
on the open lawn spreads
out into a massive, round-headed
tree.
Range: Eastern Canada and United States.
Soil and location: Prefers a rich, well-drained
soil, but will grow in
any good soil.
Enemies: Aphides or plant lice that suck
the sap from the leaves in
spring and early summer are
the chief enemies of the tree.
Value for planting: The pleasing color of its
bark, its fine spread of
branches, which gracefully
droop down to the ground, and its
autumnal coloring, make the
beech a favorite for lawn and park
planting. The several
European species of beech are equally
charming.
[Illustration: FIG. 56.—Bark of the Hackberry.]
Commercial value: The wood is strong, close-grained,
and tough. It is
used mainly for cooperage,
tool handles, shoe lasts, chairs, etc.,
and for fuel.
Other characters: The fruit is a prickly
burr encasing a sharply
triangular nut which is sweet
and edible.
Comparisons: The European beech (Fagus
sylvatica), and its weeping,
purple-leaved, and fern-leaved
varieties, are frequently met with in
parks and may be told from
the native species by its darker bark.
The weeping form may, of course,
be told readily by its drooping
branches. The leaves
of the European beeches are broader and less
serrated than those of the
American beech.
BLUE BEECH OR HORNBEAM (Carpinus caroliniana)
Distinguishing characters: The fluted
or muscular effect of its
trunk will distinguish
the tree at a glance, Fig. 54.
Leaf: Doubly serrated; otherwise the same as that of ironwood.
Form and size: A low-spreading tree with branches
arching out at various
angles, forming a flattened
head with a fine, slender spray.
Range: Very common in the eastern United States.
Soil and location: Grows in low wet woods.
Enemies: None of importance.
Value for planting: Its artistic branching and
curious trunk give the
tree an important place in
park planting.
Commercial value: None.
Other characters: The bark is smooth and bluish gray in color.
Comparisons: The blue beech or hornbeam is often
confused with the
ironwood or hop
hornbeam (Ostrya virginiana). The ironwood,
however, has a characteristic
bark that peels in perpendicular,
short, thin segments, often
loose at the ends. See Fig. 55. This is
entirely different from the
close, smooth, and fluted bark of the
blue beech. The color
of the bark in the ironwood is brownish, while
that of the blue beech is
bluish-gray. The buds of the ironwood are
greenish with brown tips,
while the bud of the blue beech shows no
green whatever.
Distinguishing characters: The tree may be told
readily from other trees
by the corky tubercles
on the bark of the lower portion of the
trunk. See Fig. 56.
Leaf: Has three predominating veins and is a
bit more developed on one
side than on the other.
Form and size: A small or medium-sized tree with
a single stem and broad
conical crown.
Range: United States and Canada.
Soil and location: Grows naturally in fertile
soils, but will adapt
itself to almost sterile soils
as well.
Enemies: The hackberry is usually free from disease,
though often its
leaves are covered with insect
galls.
Value for planting: It is extensively planted
as a shade tree in the
Middle West, and is frequently
seen as an ornamental tree in the
East.
Commercial value: It has little economic value except for fuel.
Other characters: The fruit is berry-like,
with a hard pit. The fleshy
outer part is sweet.
Other common names: Nettle tree; sugarberry.
How to tell them from other trees: The oaks are
rather difficult to
identify and, in studying
them it will often be necessary to look
for more than one distinguishing
character. The oaks differ from
other trees in bearing acorns.
Their leaves have many lobes and
their upper lateral buds
cluster at the top of the twigs. The
general contour of each oak
presents a characteristic branching and
sturdiness uncommon in other
trees.
The chestnut differs from
other trees in bearing burs and its
bark is also distinctly
characteristic.
How to tell them from each other: There are two
groups of oaks, the
white oak and the black
oak. The white oaks mature their acorns
in one year and, therefore,
only acorns of the same year can be
found on trees of this group.
The black oaks take two years in which
to mature their acorns and,
therefore, young acorns of the present
year and mature acorns of
the previous year may be found on the same
tree at one time. The
leaves of the white oaks have rounded
margins and rounded lobes
as in Fig. 57, while those of the black
oaks have pointed margins
and sharp pointed lobes as shown in Figs.
60, 62 and 64. The bark
of the white oaks is light colored and
breaks up in loose flakes
as in Fig. 58, while that of the black
oaks is darker and deeply
ridged or tight as in Figs. 59 and 61. The
white oak is the type of the
white oak group and the black, red and
pin oaks are types of the
other. For the characterization of the
individual species, the reader
is referred to the following pages.
[Illustration: FIG. 57.—Leaf and Fruit of White Oak. (Quercus alba.)]
Distinguishing characters: The massive ramification
of its branches is
characteristic of this species
and often an easy clue to its
identification. The bark
has a light gray color—lighter than
that of the other oaks—and
breaks into soft, loose flakes as in
Fig. 58. The leaves
are deeply lobed as in Fig. 57. The buds
are
small, round and congested
at the end of the year’s growth. The
acorns usually have no stalks
and are set in shallow, rough cups.
The kernels of the acorns
are white and palatable.
Form and size: The white oak grows into a large
tree with a
wide-spreading, massive crown,
dissolving into long, heavy, twisted
branches. When grown
in the open it possesses a short sturdy trunk;
in the forest its trunk is
tall and stout.
Range: Eastern North America.
[Illustration: FIG. 58.—Bark of White Oak. (Quercus alba.)]
Soil and location: The white oak thrives in almost
any well-drained,
good, deep soil except in
a very cold and wet soil. It requires
plenty of light and attains
great age.
Enemies: The tree is comparatively free from
insects and disease except
in districts where the Gipsy
moth is common, in which case the
leaves of the white oak are
a favorite food of its caterpillars.
[Illustration: FIG. 59.—Bark of Black Oak. (Quercus velutina).]
Value for planting: The white oak is one of the
most stately trees. Its
massive form and its longevity
make the tree suitable for both lawn
and woodland planting but
it is not used much because it is
difficult to transplant and
grows rather slowly.
Commercial value: The wood is of great economic
importance. It is heavy,
hard, strong and durable and
is used in cooperage, construction
work, interior finish of buildings
and for railroad ties, furniture,
agricultural implements and
fuel.
Comparisons: The swamp white oak (Quercus
platanoides) is similar to
the white oak in general appearance
of the bark and form and is
therefore liable to be confused
with it. It differs from the white
oak, however, in possessing
a more straggly habit and in the fact
that the bark on the under
side of its branches shags in loose,
large scales. Its buds
are smaller, lighter colored and more downy
and its acorns are more pointed
and with cups more shallow than
those of the white oak.
The tree also grows in moister ground,
generally bordering swamps.
[Illustration: FIG. 60.—Leaf and Fruit of Black Oak. (Quercus velutina).]
Distinguishing characters: The bark is
black, rough and cut up into
firm ridges especially
at the base of the tree, see Fig. 59. The
inner bark has a bright
yellow color: the leaves have sharp
points and are wider at
the base than at the tip as shown in Fig.
60. The buds are large,
downy and sharp pointed. The acorns
are
small and have deep, scaly
cups the inner margins of which are
downy. The kernels are
yellow and bitter.
Form and size: The tree grows in an irregular
form to large size, with
its branches rather slender
as compared with the white oak and with
a more open and narrow crown.
Range: Eastern North America.
Soil and location: It will grow in poor soils
but does best where the
soil is rich and well drained.
Enemies: None of importance.
Value for planting: The black oak is the poorest
of the oaks for
planting and is rarely offered
by nurserymen.
Commercial value: The wood is heavy, hard and
strong, but checks readily
and is coarse grained.
It is of little value except for fuel. The
bark is used for tannin.
Other common names: Yellow oak.
Comparisons: The black oak might sometimes be
confused with the red
and scarlet oaks.
The yellow, bitter inner bark will distinguish
the black oak from the other
two. The light-colored, smooth bark of
the red oak and the dark,
ridged bark of the black oak will
distinguish the two, while
the bark of the scarlet oak has an
appearance intermediate between
the two. The buds of the three
species also show marked differences.
The buds of the black oak are
covered with hairs, those
of the scarlet oak have fewer hairs and
those of the red are practically
free from hairs. The leaves of each
of the three species are distinct
and the growth habits are
different.
Distinguishing characters: The bark is
perpendicularly fissured into
long, smooth, light gray
strips giving the trunk a characteristic
pillar effect as in
Figs. 61 and 94. It has the straightest trunk
of all the oaks. The
leaves possess more lobes than the leaves of
any of the other species of
the black oak group, see Fig. 62. The
acorns, the largest among
the oaks, are semispherical with the cups
extremely shallow. The
buds are large and sharp pointed, but not as
large as those of the black
oak. They also have a few fine hairs on
their scales, but are not
nearly as downy as those of the Black oak.
[Illustration: FIG. 61—Bark of Red Oak.]
Form and size: The red oak is the largest of
the oaks and among the
largest of the trees in the
northern forests. It has a straight
trunk, free from branches
to a higher point than in the white oak,
see Fig. 94. The branches
are less twisted and emerge at sharper
angles than do those of the
white oak.
Range: It grows all over Eastern North America
and reaches north farther
than any of the other oaks.
Soil and location: It is less fastidious in its
soil and moisture
requirements than the other
oaks and therefore grows in a great
variety of soils. It
requires plenty of light.
[Illustration: FIG. 62.—Leaf and Fruit of Red Oak.]
Enemies: Like most of the other oaks, this species
is comparatively free
from insects and disease.
Value for planting: The red oak grows faster
and adapts itself better to
poor soil conditions than
any of the other oaks and is therefore
easy to plant and easy to
find in the nurseries. It makes an
excellent street tree, is
equally desirable for the lawn and is
hardly surpassed for woodland
planting.
Commercial value: The wood is hard and strong
but coarse grained, and is
used for construction timber,
interior finish and furniture. It is
inferior to white oak where
strength and durability are required.
Distinguishing characters: Its method of branching
will characterize
the tree at a glance.
It develops a well-defined main ascending
stem with numerous
drooping side branches as in Fig. 63.
The
buds are very small and sharp
pointed and the leaves are small as in
Fig. 64. The bark is
dark, firm, smooth and in close ridges. The
acorn is small and carries
a light brown, striped nut, wider than
long and bitter. The
cup is shallow, enclosing only the base of the
nut.
[Illustration: FIG. 63.—Pin Oaks in Winter.]
Form and size: The pin oak is a medium-sized
tree in comparison with
other oaks. It develops
a tall, straight trunk that tapers
continuously through a pyramidal
crown of low, drooping tender,
branches.
Range: Eastern North America.
Soil and location: It requires a deep, rich,
moist soil and grows
naturally near swamps.
Its roots are deep and spreading. The tree
grows rapidly and is easily
transplanted.
Enemies: None of importance.
Value for planting: The pin oak is an extremely
graceful tree and is
therefore extensively used
for planting on lawns and on certain
streets where the tree can
find plenty of water and where conditions
will permit its branches to
droop low.
Commercial value: The wood is heavy and hard
but coarse grained and
liable to check and warp.
Its principal use is in the construction
of houses and for shingles.
[Illustration: FIG. 64.—Leaf and Fruit of Pin Oak.]
Distinguishing characters: The bark in
young trees is smooth and of a
marked reddish-bronze color,
but when the tree grows older, the bark
breaks up into diamond-shaped
ridges, sufficiently characteristic
to distinguish the tree at
a glance, see Fig. 65. A close
examination of the terminal
twig will show three ridges and two
grooves running down along
the stem from the base of each leaf or
leaf-scar. The twig has
no true terminal bud. The fruit, a large,
round bur, prickly
without and hairy within and enclosing the
familiar dark brown, sweet
edible nuts is also a distinguishing mark
of the tree.
Leaf: The leaves are distinctly long and narrow.
They are from 6 to 8
inches long.
Form and size: The chestnut is a large tree with
a massive trunk and
broad spreading crown.
The chestnut tree when cut, sprouts readily
from the stump and therefore
in places where the trees have once
been cut, a group of two to
six trees may be seen emerging from the
old stump.
[Illustration: FIG. 65.—Trunk of Chestnut Tree.]
Range: Eastern United States.
Soil and location: It will grow on rocky as well
as on fertile soils and
requires plenty of light.
Enemies: During the past nine years nearly all
the chestnut trees in the
United States have been attacked
by a fungus disease (Diaporthe
parasitica, Mur.) which
still threatens the entire extinction of
the chestnut trees in this
country. No remedy has been discovered
and all affected trees should
be cut down and the wood utilized
before it decays and becomes
worthless. No species of chestnut tree
is entirely immune from this
disease, though some species are highly
resistant.
Value for planting: The chestnut is one of the
most rapidly growing
hardwood trees but, on account
of its disease, which is now
prevalent everywhere, it is
not wise to plant chestnut trees for the
present.
Commercial value: The wood is light, not very
strong and liable to warp.
It is durable when brought
in contact with the soil and is therefore
used for railroad ties, fence-posts,
poles, and mine timbers. It is
also valuable for interior
finish in houses and for fuel. Its bark
is used in the manufacture
of tanning extracts and the nuts are sold
in cities in large quantities.
HOW TO IDENTIFY TREES—(Continued)
How to tell them from other trees and from each other:
The hickory
trees, though symmetrical,
have a rugged appearance and the
branches are so sturdy
and black as to give a special distinction
to this group. The buds
are different from the buds of all other
trees and sufficiently characteristic
to distinguish the various
species of the group.
The bark is also a distinguishing character.
The walnut and butternut have
chambered piths which distinguish
them from all other trees
and from each other.
Distinguishing characters: The yellowish brown
buds nearly as large as
those of the mockernut hickory,
are each provided with two long,
dark, outer scales which
stand out very conspicuously as shown in
Fig. 67. The bark
in older specimens shags off in rough strips,
sometimes more than a foot
long, as shown in Fig. 68. These two
characters will readily distinguish
the tree at all seasons of the
year.
[Illustration: FIG. 66.—A Shagbark Hickory Tree.]
Leaf: The leaf is compound, consisting of 5 or
7 leaflets, the terminal
one generally larger.
Form and size: A tall, stately tree—the
tallest of the hickories—of
rugged form and fine symmetry,
see Fig. 66.
Range: Eastern North America.
Soil and location: The shagbark hickory grows
in a great variety of
soils, but prefers a deep
and rather moist soil.
Enemies: The hickory bark borer (Scolytus
quadrispinosus) is its
principal enemy. The
insect is now killing thousands of hickory
trees in the vicinity of New
York City and on several occasions has
made its appearance in large
numbers in other parts of the country.
Value for planting: It is difficult to transplant,
grows slowly and is
seldom found in nurseries.
[Illustration: FIG. 67.—Bud of the Shagbark Hickory.]
Commercial value: The wood is extremely tough
and hard and is used for
agricultural implements and
for the manufacture of wagons. It is
excellent for fuel and the
nuts are of great value as a food.
Other characters: The fruit is a nut covered
by a thick husk that
separates into 4 or 5 segments.
The kernel is sweet.
Other common names: Shellbark hickory.
[Illustration: FIG. 68.—Bark of the Shagbark Hickory.]
Distinguishing characters: The bud is
the largest among the
hickories—nearly
half an inch long—is hard and oval and covered
with yellowish brown
downy scales which do not project like
those of the shagbark hickory,
see Fig. 69. The twigs are extremely
coarse. The bark
is very tight on the trunk and branches and has a
close, hard, wavy
appearance as in Fig. 70.
Leaf: The leaf consists of 5, 7 or 9 leaflets
all of which are large and
pubescent and possess a distinct
resinous odor.
Form and size: A tall tree with a broad spreading head.
Range: Eastern North America.
Soil and location: The mockernut hickory grows
on a great variety of
soils, but prefers one which
is rich and well-drained.
Enemies: The same as for the shagbark hickory.
Value for planting: It is not commonly planted.
Commercial value: The wood is similar to that
of the shagbark hickory
and is put to the same uses.
Other characters: The fruit is a nut, larger
and covered with a shell
thicker than that of the shagbark.
The husk is also thicker and
separates into four segments
nearly to the base. The kernel is small
and sweet.
Other common names: Bigbud hickory; whiteheart hickory.
Comparisons: The pignut hickory (Hicoria
glabra), sometimes called
broom hickory or brown hickory,
often has a shaggy bark, but differs
from both the shagbark and
the mockernut hickory in possessing buds
very much smaller, twigs more
slender and leaflets fewer. The nut
has a thinner husk which does
not separate into four or five
segments. The tree prefers
drier ground than the other hickories.
[Illustration: FIG. 69.—Bud of the Mockernut Hickory.]
The bitternut (Hicoria minima) can be told from the mockernut and other species of hickory by its bud, which has no scales at all. The color of its bud is a characteristic orange yellow. The bark is of a lighter shade than the bark of the mockernut hickory and the leaflets are more numerous than in any of the hickories, varying from 7 to 11. Its nuts are bitter.
Distinguishing characters: By cutting a twig
lengthwise, it will be seen
that its pith is divided
into little chambers as shown in Fig.
71. The bud is dark gray
and satiny. The bark is dark brown and
deeply ridged and the fruit
is the familiar round walnut.
[Illustration: FIG. 70.—Bark of the Mockernut Hickory.]
Form and size: A tall tree with a spreading crown
composed of stout
branches. In the open
it grows very symmetrically.
Range: Eastern United States.
Soil and location: The black walnut prefers a
deep, rich, fertile soil
and requires a great deal
of light.
Enemies: The tree is a favorite of many caterpillars.
Value for planting: It forms a beautiful spreading
tree on open ground,
but is not planted to any
extent because it is hard to transplant.
It grows slowly unless the
soil is very deep and rich, develops its
leaves late in the spring
and sheds them early in the fall and
produces its fruit in great
profusion.
Commercial value: The wood is heavy, strong,
of chocolate brown color
and capable of taking a fine
polish. It is used for cabinet making
and interior finish of houses.
The older the tree, usually, the
better the wood, and the consumption
of the species in the past has
been so heavy that it is becoming
rare. The European varieties which
are frequently planted in
America as substitutes for the native
species yield better nuts,
but the American species produces better
wood.
[Illustration: FIG. 71.—Twig of the Black Walnut. Note the large chambers in the pith.]
[Illustration: FIG. 72.—Twig of the Butternut. Note the small chambers in the pith.]
Other characters: The fruit is a large
round nut about two inches in
diameter, covered with a smooth
husk which at first is dull green
in color and later turns brown.
The husk does not separate into
sections. The kernel
is edible and produces an oil of commercial
value.
The leaves are compound
and alternate with 15 to 23 leaflets to
each.
Comparisons: The butternut (Juglans
cinerea) is another tree that
has the pith divided into
little chambers, but the little chambers
here are shorter than in the
black walnut, as may be seen from a
comparison of Figs. 71 and
72. The bark of the butternut is light
gray while that of the black
walnut is dark. The buds in the
butternut are longer than
those of the black walnut and are light
brown instead of gray in color.
The form of the tree is low and
spreading as compared with
the black walnut. The fruit in the
butternut is elongated while
that of the black walnut is round. The
leaves of the butternut have
fewer leaflets and these are lighter in
color.
GROUP X. TULIP TREE, SWEET GUM, LINDEN, MAGNOLIA, LOCUST, CATALPA, DOGWOOD, MULBERRY AND OSAGE ORANGE
TULIP TREE (Liriodendron tulipifera)
Distinguishing characters: There are four characters
that stand out
conspicuously in the tulip
tree—the bud, the trunk, the
persistent fruit cups
and the wedged leaf.
The bud, Fig. 74, about three-quarters of an inch long, is covered by two purplish scales which lend special significance to its whole appearance. The trunk is extremely individual because it rises stout and shaft-like, away above the ground without a branch as shown in Fig. 73. The tree flowers in the latter part of May but the cup that holds the fruit persists throughout the winter. The leaf, Fig. 75, has four lobes, is nearly as broad as it is long and so notched at the upper end that it looks different from any other leaf.
[Illustration: FIG. 73.—The Tulip Tree.]
[Illustration: FIG. 74.—Bud of the Tulip Tree.]
Form and size: The tulip tree is one of the largest,
stateliest and
tallest of our trees.
Range: Eastern United States.
Soil and location: Requires a deep, moist soil.
Enemies: Comparatively free from insects and disease.
Value for planting: The tree has great value
as a specimen on the lawn
but is undesirable as a street
tree because it requires considerable
moisture and transplants with
difficulty. It should be planted while
young and where it can obtain
plenty of light. It grows rapidly.
Commercial value: The wood is commercially known
as whitewood and
yellow poplar.
It is light, soft, not strong and easily worked.
It
is used in construction, for
interior finish of houses, woodenware
and shingles. It has
a medicinal value.
Other characters: The flower, shown in
Fig. 75, is greenish yellow in
color, appears in May and
resembles a tulip; hence the name tulip
tree. The fruit
is a cone.
Other common names: Whitewood; yellow
poplar; poplar and tulip
poplar.
[Illustration: FIG. 75.—Leaf and Flower of the Tulip Tree.]
Distinguishing characters: The persistent,
spiny, long-stemmed round
fruit; the corky
growths on the twigs, the characteristic
star-shaped leaves
(Fig. 76) and the very shiny greenish brown
buds and the perfect symmetry
of the tree are the chief characters
by which to identify the species.
Form and size: The sweet gum has a beautiful
symmetrical shape, forming
a true monopodium.
[Illustration: FIG. 76.—Leaf and Fruit of the Sweet Gum. Note the corky ridges along the twig.]
Range: From Connecticut to Florida and west to Missouri.
Soil and location: Grows in any good soil but
prefers low wet ground. It
grows rapidly and needs plenty
of light.
Enemies: Is very often a favorite of leaf-eating caterpillars.
Value for planting: The tree is sought for the
brilliant color of its
foliage in the fall, and is
suitable for planting both on the lawn
and street. In growing
the tree for ornamental purposes it is
important that it should be
frequently transplanted in the nursery
and that it be transported
with burlap wrapping around its roots.
Commercial value: The wood is reddish brown in
color, tends to splinter
and is inclined to warp in
drying. It is used in cooperage, veneer
work and for interior finish.
Other characters: On the smaller branches there
are irregular
developments of cork as shown
in Fig. 76, projecting in some cases
to half an inch in thickness.
Other common names: Red gum.
Comparisons: The cork elm is another tree
that possesses corky ridges
along its twigs, but this
differs from the sweet gum in wanting the
spiny fruit and its other
distinctive traits.
[Illustration: FIG. 77.—Bud of the Linden Tree.]
Distinguishing characters: The great distinguishing
feature of any
linden is the one-sided
character of its bud and leaf. The
bud, dark red and conical,
carries a sort of protuberance which
makes it extremely one sided
as shown in Fig. 77. The leaf, Fig. 78,
is heart-shaped with the side
nearest the branch largest.
[Illustration: FIG. 78.—Leaves and Flowers of the European Linden.]
Form and size: The American Linden is a medium-sized
tree with a broad
round head.
Range: Eastern North America and more common
in the north than in the
south.
Soil and location: Requires a rich, moist soil.
[Illustration: FIG. 79.—European Linden Tree.]
[Illustration: FIG. 80.—Bud of the Umbrella Tree.]
Enemies: Its leaves are a favorite food of caterpillars
and its wood is
frequently attacked by a boring
insect known as the linden borer
(Saperda vestita).
Value for planting: The linden is easily transplanted and grows rapidly. It is used for lawn and street planting but is less desirable for these purposes than the European species.
Commercial value: The wood is light and soft
and used for paper pulp,
woodenware, cooperage and
furniture. The tree is a favorite with bee
keepers on account of the
large quantities of nectar contained in
its flowers.
Other characters: The fruit is like a
pea, gray and woody. The
flowers appear in early
July, are greenish-yellow and very
fragrant.
Other common names: Bass-wood; lime-tree; whitewood.
Comparisons: The European lindens, Fig.
79, of which there are several
species under cultivation,
differ from the native species in having
buds and leaves smaller in
size, more numerous and darker in color.
The various species of magnolia trees are readily distinguished by their buds. They all prefer moist, rich soil and have their principal value as decorative trees on the lawn. They are distinctly southern trees; some species under cultivation in the United States come from Asia, but the two most commonly grown in the Eastern States are the cucumber tree and the umbrella tree.
[Illustration: FIG. 81.—Bark of the Black Locust.]
Distinguishing characters: The buds are
small and slender compared
with those of the other magnolia
trees and are covered with small
silvery silky hairs.
The habit of the tree is to form a straight
axis of great height with
a symmetrical mass of branches, producing
a perfect monopodial crown.
The tree is sometimes known as mountain
magnolia.
Distinguishing characters: The buds, Fig.
80, are extremely long,
often one and a half inches,
have a purple color and are smooth.
The tree does not grow to
large size and produces an open spreading
head. Its leaves, twelve
to eighteen inches long, are larger than
those of the other magnolia
trees. The tree is sometimes called
elkwood.
Distinguishing characters: The bark of
the trunk is rough and
deeply ridged, as shown
in Fig. 81. The buds are hardly
noticeable; the twigs
sometimes bear small spines on one side. The
leaves are large, compound,
and fern-like. The individual leaflets
are small and delicate.
Form and size: The locust is a medium-sized tree
developing a slender
straight trunk when grown
alongside of others; see Fig. 82.
Range: Canada and United States.
Soil and location: The locust will grow on almost
any soil except a wet,
heavy one. It requires
plenty of light.
Enemies: The locust borer has done serious
damage to this tree. The
grubs of this insect burrow
in the sapwood and kill the tree or make
it unfit for commercial use.
The locust miner is a beetle which is
now annually defoliating trees
of this species in large numbers.
Value for planting: It has little value for ornamental planting.
Commercial value: Though short-lived, the locust
grows very rapidly. It
is extremely durable in contact
with the soil and possesses great
strength. It is therefore
extensively grown for fence-posts and
railroad ties. Locust
posts will last from fifteen to twenty years.
The wood is valuable for fuel.
[Illustration: FIG. 82.—Black Locust Trees.]
Other characters: The flowers are showy
pea-shaped panicles appearing
in May and June. The
fruit is a small pod.
Other common names: Yellow locust; common locust; locust.
Comparisons: The honey locust (Gleditsia
triacanthos) can be told
from the black locust by the
differences in their bark. In the honey
locust the bark is not ridged,
has a sort of dark iron-gray color
and is often covered with
clusters of stout, sharp-pointed thorns as
in Fig. 83. The fruit
is a large pod often remaining on the tree
through the winter. This
tree has an ornamental, but no commercial
value.
[Illustration: FIG. 83.—Bark of the Honey Locust.]
Distinguishing characters: The tree may be told
by its fruit, which
hang in long slender pods
all winter. The leaf-scars appear on the
stem in whorls of three and
rarely opposite each other.
Form and size: The catalpa has a short, thick
and twisted trunk with an
irregular head.
Range: Central and eastern United States.
[Illustration: FIG. 84.—Hardy Catalpa Trees.]
[Illustration: FIG. 85.—Bark of the Flowering Dogwood.]
Soil and location: It grows naturally on low
bottom-lands but will also
do well in poor, dry soils.
Enemies: Practically free from disease and insects.
Value for planting: The catalpa grows very rapidly
and is cultivated in
parks for ornament and in
groves for commercial purposes. The hardy
catalpa is preferable
to the common catalpa for planting.
Commercial value: The wood is extremely durable
in contact with the soil
and is consequently used for
posts and railroad ties.
Other characters: The flowers, which appear
in late June and early
July, are large, white and
very showy.
Other common names: Indian bean; western catalpa.
Comparisons: The white flowering dogwood
(Cornus florida) is a small
tree which also has its leaves
in whorls of three or sometimes
opposite. It can be readily
told from other trees, however, by the
small square plates into which
the outer bark on the trunk divides
itself, see Fig. 85, and by
the characteristic drooping character of
its branches. It is one
of the most common plants in our eastern
deciduous forests. It
is extremely beautiful both in the spring and
in the fall and is frequently
planted for ornament. There are many
varieties of dogwood in common
use.
A small tree recognized by its small round reddish brown buds and light brown, finely furrowed (wavy looking) bark.
The tree, probably a native of China, is grown under cultivation in eastern Canada and United States. It grows rapidly in moist soil and is not fastidious in its light requirements. Its chief value is for screening and for underplanting in woodlands.
The red mulberry (Morus rubra) is apt to be confused with the white mulberry, but differs in the following characters: The leaves of the red mulberry are rough on the upper side and downy on the under side, whereas the leaves of the white mulberry are smooth and shiny. The buds in the red are larger and more shiny than those of the white.
The Osage orange (Toxylon pomiferum) is similar to the mulberry in the light, golden color of its bark, but differs from it in possessing conspicuous spines along the twigs and branches and a more ridged bark.
THE STRUCTURE AND REQUIREMENTS OF TREES
To be able fully to appreciate trees, their mode of life, their enemies and their care, one must know something of their structure and life requirements.
Structure of trees: Among the lower forms of
plants there is very little
distinction between the various
parts—no differentiation into root,
stem, or crown. Often
the lower forms of animal and vegetable life
are so similar that one cannot
discriminate between them. But as we
ascend in the scale, the various
plant forms become more and more
complex until we reach the
tree, which is the largest and highest
form of all plants. The
tree is a living organism composed of cells
like any other living organism.
It has many parts, every one of
which has a definite purpose.
The three principal parts are: the
stem, the crown, and the root.
The stem: If we examine the cross-section
of a tree, Fig. 86, we will
notice that it is made up
of numerous rings arranged in sections of
different color and structure.
The central part is known as the
pith. Around the
pith comes a dark, close-grained series of rings
known as the heartwood,
and outside the heartwood comes a lighter
layer, the sapwood.
The cambium layer surrounds the sapwood and
the bark covers all.
The cambium layer is the most important
tissue of the tree and, together
with part of the sapwood,
transports the water and food
of the tree. It is for this reason
that a tree may be hollow,
without heart and sapwood, and still
produce foliage and fruit.
[Illustration: FIG. 86.—The Cross-Section of a Tree.]
The crown: The crown varies in form
in different species and is
developed by the growth of
new shoots from buds. The bud grows out
to a certain length and forms
the branch. Afterwards it thickens
only and does not increase
in length. New branches will then form
from other buds on the same
branch. This explains in part the
characteristic branching of
trees, Fig. 87.
[Illustration: FIG. 87.—Characteristic Form and Branching of Trees. The trees in the photograph are pin oaks.]
The leaves are the stomach and lungs of the tree. Their broad blades are a device to catch the sunlight which is needed in the process of digesting the food of the tree. The leaves are arranged on the twigs in such a way as to catch the most sunlight. The leaves take up the carbonic acid gas from the air, decompose it under the influence of light and combine it with the minerals and water brought up by the roots from the soil. The resulting chemical combinations are the sugars and starches used by the cambium layer in building up the body of the tree. A green pigment, chlorophyll, in the leaf is the medium by which, with the aid of sunlight, the sugars are manufactured.
[Illustration: FIG. 88.—Roots of a Hemlock Tree in their Search for Water.]
The chlorophyll gives the leaf its green color, and this explains why a tree pales when it is in a dying condition or when its life processes are interfered with. The other colors of the leaf—the reds, browns and yellows of the fall or spring—are due to other pigments. These are angular crystals of different hues, which at certain times of the year become more conspicuous than at others, a phenomenon which explains the variation in the colors of the leaves during the different seasons.
It is evident that a tree is greatly dependent upon its leaves for the manufacture of food and one can, therefore, readily see why it is important to prevent destruction of the leaves by insects or through over-trimming.
The root: The root develops in much
the same manner as the crown. Its
depth and spread will vary
with the species but will also depend
somewhat upon the condition
of the soil around it. A deep or a dry
soil will tend to develop
a deep root, while a shallow or moist soil
will produce a shallow root,
Fig. 88.
The numerous fine hairs which cover the roots serve the purpose of taking up food and water from the soil, while the heavy roots help to support the tree. The root-hairs are extremely tender, are easily dried out when exposed to the sun and wind, and are apt to become overheated when permitted to remain tightly packed for any length of time. These considerations are of practical importance in the planting of trees and in the application of fertilizers. It is these fine rootlets far away from the trunk of the tree that have to be fed, and all fertilizers must, therefore, be applied at points some distance from the trunk and not close to it, where merely the large, supporting roots are located. In the cultivation of trees the same principle holds true.
Requirements of trees: Trees are dependent upon
certain soil and
atmospheric conditions which
influence their growth and development.
(1) Influence of moisture: The form
of the tree and its growth and
structure depend greatly upon
the supply of moisture. Botanists
have taken the moisture factor
as the basis of classification and
have subdivided trees into
those that grow in moist places
(hydrophytes), those
that grow in medium soils (mesophytes), and
those that grow in dry places
(xerophytes). Water is taken up by
the roots of the tree from
the soil. The liquid absorbed by the
roots carries in solution
the mineral salts—the food of the
tree—and no food
can be taken up unless it is in solution. Much
of
the water is used by the tree
and an enormous amount is given off in
the process of evaporation.
[Illustration: FIG. 89.—Dead Branches at the Top Caused by Insufficient Water.]
These facts will explain some of the fundamental principles in the care of trees. To a tree growing on a city street or on a lawn where nature fails to supply the requisite amount of water, the latter must be supplied artificially, especially during the hot summer months, or else dead branches may result as seen in Fig. 89. Too much thinning out of the crown causes excessive evaporation, and too much cutting out in woodlands causes the soil to dry and the trees to suffer for the want of moisture. This also explains why it is essential, in wooded areas, to retain on the ground the fallen leaves. In decomposing and mixing with the soil, the fallen leaves not only supply the trees with food material, but also tend to conserve moisture in the ground and to prevent the drying out of the soil. RakingPage 38
off the leaves from wooded areas, a practice common in parks and on private estates—hurts the trees seriously. Some soils may have plenty of moisture, but may also be so heavily saturated with acids or salts that the tree cannot utilize the moisture, and it suffers from drought just the same as if there had been no moisture at all in the soil. Such soils are said to be “physiologically dry” and need treatment.
In the development of disease, moisture is a contributing factor and, therefore, in cavities or underneath bandages where there is likely to be an accumulation of moisture, decay will do more damage than in places that are dry and exposed to the sun.
(2) Influence of soil: Soil is made
up of fine particles of sand and
rock and of vegetable matter
called humus. A tree will require a
certain soil, and unsuitable
soils can be very often modified to
suit the needs of the tree.
A deep, moderately loose, sandy loam,
however, which is sufficiently
aerated and well supplied with
water, will support almost
any tree. Too much of any one constituent
will make a soil unfit for
the production of trees. If too much clay
is present the soil becomes
“stiff.” If too much vegetable matter
is
present, the soil becomes
“sour.” The physical character of
the soil
is also important. By
physical character is meant the porosity which
results from breaking up the
soil. This is accomplished by ploughing
or cultivation. In nature,
worms help to do this for the soil, but
on streets an occasional digging
up of the soil about the base of
the tree is essential.
Humus or the organic matter in the soil is composed of litter, leaves and animal ingredients that have decayed under the influence of bacteria. The more vegetable matter in the humus, the darker the soil; and therefore a good soil such as one finds on the upper surface of a well-tilled farm has quite a dark color. When, however, a soil contains an unusual quantity of humus, it is known as “muck,” and when there is still more humus present we find peat. Neither of these two soils is suitable for proper tree growth.
[Illustration: FIG. 90.—A Tree in the Open. Note the full development of the wide crown with branches starting near the ground. The tree is the European larch.]
(3) Influence of light: Light is
required by the leaves in the process
of assimilation. Cutting
off some of the light from a tree affects
its form. This is why
trees grown in the open have wide-spreading
crowns with branches starting
near the ground as in Fig. 90, while
the same species growing in
the forest produces tall, lanky trees,
free from branches to but
a few feet from the top as in Fig. 91.
Some trees can endure more
shade than others, but all will grow in
[Illustration: FIG. 91.—A Tree in The Forest. Note the tall stem free from branches and the small, narrow crown.]
(4) Influence of heat: Trees require
a certain amount of heat. They
receive it partly from the
sun and partly from the soil. Evaporation
prevents the overheating of
the crown. The main stem of the tree is
heated by water from the soil;
therefore trees in the open begin
growth in the spring earlier
than trees in the forest because the
soil in the open is warmer.
Shrubs begin their growth earlier than
trees because of the nearness
of their crowns to their root systems.
This also explains why a warm
rain will start vegetation quickly.
Too much heat will naturally
cause excessive drying of the roots or
excessive evaporation from
the leaves and therefore more water is
needed by the tree in summer
than in winter.
(5) Influence of season and frost:
The life processes of a tree are
checked when the temperature
sinks below a certain point. The tree
is thus, during the winter,
in a period of rest and only a few
chemical changes take place
which lead up to the starting of
vegetation. In eastern
United States, growth starts in April and
ceases during the latter part
of August or in early September. The
different parts of a tree
may freeze solid during the winter without
injury, provided the tree
is a native one. Exotic trees may suffer
greatly from extreme cold.
This is one of the main reasons why it is
always advisable to plant
native trees rather than those that are
imported and have not yet
been acclimatized. Frosts during
mid-winter are not quite as
injurious as early and late frosts and,
therefore, if one is going
to protect plants from the winter’s cold,
it is well to apply the covering
early enough and to keep it on
late enough to overcome this
difficulty.
The mechanical injuries from frost are also important. Snow and sleet will weigh down branches but rarely break them, while frost will cause them to become brittle and to break easily. Those who climb and prune trees should be especially cautious on frosty days.
(6) Influence of air: On the under
side of leaves and on other
surfaces of a tree little
pores known as stomata may be found. In
the bark of birch and cherry
Conclusions: From the foregoing it will be seen
that trees have certain
needs that nature or man must
supply. These requirements differ
with the different species,
and in all work of planting and care as
well as in the natural distribution
of trees it is both interesting
and necessary to observe these
individual wants, to select species
in accordance with local conditions
and to care for trees in
conformity with their natural
needs.
WHAT TREES TO PLANT AND HOW
The following classification will show the value of the more important trees for different kinds of planting. The species are arranged in the order of their merit for the particular object under consideration and the comments accompanying each tree are intended to bring out its special qualifications for that purpose.
Conditions for tree growth in one part of the country differ from those of another and these lists, especially applicable to the Eastern States, may not at all fit some other locality.
DECIDUOUS
1. American elm (Ulmus americana)
One of the noblest of trees.
Possesses a majestic, wide-spreading,
umbrella-shaped crown; is
easily transplanted, and is suited to a
variety of soils.
2. Pin oak (Quercus palustris)
Has a symmetrical crown with
low-drooping branches; requires a moist
situation.
3. European linden (Tilia microphylla)
Possesses a beautiful shade-bearing
crown; grows well in ordinary
soil.
4. Red maple (Acer rubrum)
Shows pleasing colors at all
seasons; grows best in a fairly rich,
moist soil.
5. Copper beech (Fagus sylvatica, alropurpurea)
Exceedingly beautiful in form, bark, and foliage and possesses great longevity and sturdiness. It is difficult to transplant and therefore only small trees from 6 to 10 feet in height should be used.
6. Coffee tree (Gymnocladus dioicus)
A unique and interesting effect
is produced by its coarse branches
and leaves. It is free
from insects and disease; requires plenty of
light; will grow in poor soils.
7. European white birch (Belula alba)
A graceful tree and very effective
as a single specimen on the lawn,
or in a group among evergreens;
should be planted in early spring,
and special care taken to
protect its tender rootlets.
8. Gingko or Maiden-hair tree (Gingko biloba)
Where there is plenty of room
for the spread of its odd branches,
the gingko makes a picturesque
specimen tree. It is hardy and free
from insect pests and disease.
9. Horsechestnut (Aesculus hippocastanum)
Carries beautiful, showy flowers, and has a compact, symmetrical low-branched crown; is frequently subject to insects and disease. The red flowering horsechestnut (A. rubicunda) is equally attractive.
[Illustration: FIG. 92.—A Lawn Tree. European Weeping Beech.]
10. Sugar maple (Acer saccharum)
Has a symmetrical crown and
colors beautifully in the fall; requires
a rich soil and considerable
moisture.
11. Soulange’s magnolia (Magnolia soulangeana)
Extremely hard and flowers in early spring before the leaves appear.
12. Flowering dogwood (Cornus florida)
Popular for its beautiful white flowers in the early spring and the rich coloring of its leaves in the fall; does not grow to large size. The red-flowering variety of this tree, though sometimes not quite as hardy, is extremely beautiful.
13. Japanese maple (Acer polymorphum)
It has several varieties of
different hues and it colors beautifully
in the fall; it does not grow
to large size.
14. Oriental spruce (Picea orientalis)
Forms a dignified, large tree
with a compact crown and low branches;
is hardy.
15. Austrian pine (Pinus austriaca)
Is very hardy; possesses a
compact crown; will grow in soils of
medium quality.
16. Bhotan pine (Pinus excelsa)
Grows luxuriantly; is dignified
and beautiful; requires a good soil,
and in youth needs some protection
from extreme cold.
17. White pine (Pinus strobus)
Branches gracefully and forms
a large, dignified tree; will thrive
on a variety of soils.
18. European larch (Larix europaea)
Has a beautiful appearance; thrives best in moist situations.
19. Blue spruce (Picea pungens)
Extremely hardy; forms a perfect specimen plant for the lawn.
20. Japanese umbrella pine (Sciadopitys verlicillata)
Very hardy; retains a compact
crown. An excellent specimen plant
when grouped with other evergreens
on the lawn. Does not grow to
large size.
21. Mugho pine (Pinus mughus)
A low-growing evergreen; hardy; important in group planting.
22. Obtuse leaf Japanese cypress (Retinospora obtusa)
Beautiful evergreen of small
size; hardy; desirable for group
planting.
23. English yew (Taxus baccata)
An excellent evergreen usually of low form; suitable for the lawn, massed with others or as a specimen plant; will grow in the shade of other trees. There are various forms of this species of distinctive value.
1. Oriental sycamore (Platanus orientalis)
Very hardy; will adapt itself
to city conditions; grows fairly fast
and is highly resistant to
insects and disease.
2. Norway maple (Acer platanoides)
Very hardy; possesses a straight
trunk and symmetrical crown; is
comparatively free from insects
and disease and will withstand the
average city conditions.
3. Red oak (Quercus rubra)
Fastest growing of the oaks;
very durable and highly resistant to
insects and disease; will
grow in the average soil of the city
street.
[Illustration: FIG. 93.—Street Trees. Norway Maples.]
4. Gingko (Gingko biloba)
Hardy and absolutely free
from insects and disease; suited for
narrow streets, and will permit
of close planting.
5. European linden (Tilia microphylla)
Beautiful shade-bearing crown;
is very responsive to good soil and
plenty of moisture.
6. American elm (Ulmus americana)
When planted in rows along an avenue, it forms a tall majestic archway of great beauty. It is best suited for wide streets and should be planted further apart than the other trees listed above. Requires a fairly good soil and plenty of moisture, and is therefore not suited for planting in the heart of a large city.
7. Pin oak (Quercus palustris)
This tree exhibits its greatest beauty when its branches are allowed to droop fairly low. It, moreover, needs plenty of moisture to thrive and the tree is therefore best suited for streets in suburban sections, where these conditions can be more readily met.
8. Red maple (Acer rubrum)
Beautiful in all seasons of
the year; requires a rich soil and
considerable moisture.
FOR OPEN PLACES
1. Red oak (Quercus rubra)
Grows rapidly to large size
and produces valuable wood; will grow in
poor soil.
2. White pine (Pinus strobus)
Rapid grower; endures but
little shade; wood valuable; will do well
on large range of soils.
3. Red pine (Pinus resinosa)
Very hardy; fairly rapid growing tree.
4. Tulip tree (Liriodendron tulipifera)
Grows rapidly into a stately forest tree with a clear tall trunk; wood valuable; requires a fairly moist soil. Use a small tree, plant in the spring, and pay special attention to the protection of the roots in planting.
5. Black locust (Robinia pseudacacia)
Grows rapidly; adapts itself
to poor, sandy soils. The wood is
suitable for posts and ties.
6. White ash (Fraxinus americana)
Grows rapidly; prefers moist situations. Wood valuable.
7. American elm (Ulmus americana)
Grows rapidly to great height;
will not endure too much shade; does
best in a deep fertile soil.
Wood valuable.
8. European larch (Larix europaea)
Grows rapidly; prefers moist situations.
[Illustration: FIG. 94.—Woodland Trees. Red Oaks.]
9. Beech (Fagus)
Will stand heavy shade; holds
the soil well along banks and steep
slopes. Both the American
and the English species are desirable.
10. Hemlock (Tsuga canadensis)
Will stand heavy shade and
look effective in winter as well as in
summer.
11. Dogwood (Cornus florida)
Will grow under other trees;
flowers beautifully in the spring and
colors richly in the fall.
12. Blue beech (Carpinus caroliniana)
Native to the woodlands of
the Eastern States; looks well in spring
and fall.
1. Hemlock (Tsuga canadensis)
Will stand shearing and will
screen in winter as well as in summer.
Plant from 2 to 4 feet apart
to form a hedge.
2. Osage orange (Toxylon pomiferum)
Very hardy. Plant close.
3. English hawthorn (Crataegus oxyacantha)
Flowers beautifully and grows in compact masses. Plant close.
4. Lombardy poplar (Populus nigra var. italica)
Forms a tall screen and grows
under the most unfavorable conditions.
Plant 8 to 12 feet apart.
Quality of trees: Trees grown in a nursery are
preferable for
transplanting to trees grown
in the forest. Nursery-grown trees
possess a well-developed root
system with numerous fibrous rootlets,
a straight stem, a symmetrical
crown, and a well-defined leader.
Trees grown in neighboring
nurseries are preferable to those grown
at great distances, because
they will be better adapted to local
climatic and soil conditions.
The short distances over which they
must be transported also will
entail less danger to the roots
through drying. For lawn
planting, the branches should reach low to
the ground, while for street
purposes the branches should start at
about seven feet from the
ground. For street planting, it is also
important that the stem should
be perfectly straight and about two
inches in diameter. For
woodland planting, the form of the tree is
of minor consideration, though
it is well to have the leader well
defined here as well as in
the other cases. See Fig. 95.
When and how to procure the trees: The trees
should be selected in the
nursery personally. Some
persons prefer to seal the more valuable
specimens with leaden seals.
Fall is the best time to make the
selection, because at that
time one can have a wider choice of
material. Selecting thus
early will also prevent delay in delivery
at the time when it is desired
to plant.
When to plant: The best time to plant trees is
early spring, just before
growth begins, and after the
frost is out of the ground. From the
latter part of March to the
early part of May is generally the
planting period in the Eastern
States.
Where one has to plant both
coniferous and deciduous trees, it is
best to get the deciduous
in first, and then the conifers.
How to plant: The location of the trees with
relation to each other
should be carefully considered.
On the lawn, they should be
separated far enough to allow
for the full spread of the tree. On
streets, trees should be planted
thirty to thirty-five feet apart
and in case of the elm, forty
to fifty feet. In woodlands, it is
well to plant as close as
six feet apart where small seedlings are
used and about twelve feet
apart in the case of trees an inch or
more in diameter. An
abundance of good soil (one to two cubic yards)
is essential with each tree
where the specimens used are an inch or
two in diameter. A rich
mellow loam, such as one finds on the
surface of a well-tilled farm,
is the ideal soil. Manure should
never be placed in direct
contact with the roots or stem of the
tree.
Protection of the roots from drying is the chief precaution to be observed during the planting process, and for this reason a cloudy day is preferable to a sunny day for planting. In case of evergreens, the least exposure of the roots is liable to result disastrously, even more so than in case of deciduous trees. This is why evergreens are lifted from the nursery with a ball of soil around the roots. All bruised roots should be cut off before the tree is planted, and the crown of the tree of the deciduous species should be slightly trimmed in order to equalize the loss of roots by a corresponding decrease in leaf surface.
The tree should be set into the tree hole at the same depth that it stood in the nursery. Its roots, where there is no ball of soil around them, should be carefully spread out and good soil should be worked in carefully with the fingers among the fine rootlets. Every root fibre is thus brought into close contact with the soil. More good soil should be added (in layers) and firmly packed about the roots. The last layer should remain loose so that it may act as a mulch or as an absorbent of moisture. The tree should then be thoroughly watered.
[Illustration: FIG. 95.—Specifications for a Street Tree.]
After care: During the first season the tree
should be watered and the
soil around its base slightly
loosened at least once a week,
especially on hot summer days.
Where trees are planted on streets,
near the curb, they should
also be fastened to stakes and protected
with a wire guard six feet
high. See Fig. 95. Wire netting of
1/2-inch mesh and 17 gauge
is the most desirable material.
[Illustration: FIG. 96.—A Home Nursery. (Austrian pines in front.)]
Suggestions for a home or school nursery: Schools,
farms, and private
estates may conveniently start
a tree nursery on the premises and
raise their own trees.
Two-year seedling trees or four-year
transplants are best suited
for this purpose. These may be obtained
from several reliable nurseries
in various parts of the country that
make a specialty of raising
small trees for such purposes. The cost
of such trees should be from
three to fifteen dollars per thousand.
The little trees, which range from one to two feet in height, will be shipped in bundles. Immediately upon arrival, the bundles should be untied and the trees immersed in a pail containing water mixed with soil. The bundles should then be placed in the ground temporarily, until they can be set out in their proper places. In this process, the individual bundles should be slanted with their tops toward the south, and the spot chosen should be cool and shady. At no time should the roots of these plants be exposed, even for a moment, to sun and wind, and they should always be kept moist. The little trees may remain in this trench for two weeks without injury. They should then be planted out in rows, each row one foot apart for conifers and two feet for broadleaf trees. The individual trees should be set ten inches apart in the row. Careful weeding and watering is the necessary attention later on.
THE CARE OF TREES
In a general way, trees are attacked by three classes of insects, and the remedy to be employed in each case depends upon the class to which the insect belongs. The three classes of insects are:
1. Those that chew and swallow some portion of the leaf; as, for example, the elm leaf beetle, and the tussock, gipsy, and brown-tail moths.
2. Those that suck the plant juices from the leaf or bark; such as the San Jose scale, oyster-shell, and scurfy scales, the cottony maple scale, the maple phenacoccus on the sugar maples, and the various aphides on beech, Norway maple, etc.
3. Those that bore inside of the wood or inner bark. The principal members of this class are the leopard moth, the hickory-bark borer, the sugar-maple borer, the elm borer, and the bronze-birch borer.
The chewing insects are destroyed by spraying the leaves with arsenate of lead or Paris green. The insects feed upon the poisoned foliage and thus are themselves poisoned.
The sucking insects are killed by a contact poison: that is, by spraying or washing the affected parts of the tree with a solution which acts externally on the bodies of the insects, smothering or stifling them. The standard solutions for this purpose are kerosene emulsion, soap and water, tobacco extract, or lime-sulfur wash.
[Illustration: FIG. 97.—A Gas-power Spraying Apparatus.]
The boring insects are eliminated by cutting out the insect with a knife, by injecting carbon bisulphide into the burrow and clogging the orifice immediately after injection with putty or soap, or in some cases where the tree is hopelessly infested, by cutting down and burning the entire tree.
[Illustration: FIG. 98.—A Barrel Hand-pump Spraying Outfit.]
For information regarding the one of these three classes to which any particular insect belongs, and for specific instructions on the application of a remedy, the reader is advised to write to his State Entomologist or to the U.S. Bureau of Entomology at Washington, D.C. The letter should state the name of the tree affected, together with the character of the injury, and should be accompanied by a specimen of the insect, or by a piece of the affected leaf or bark, preferably by both. The advice received will be authentic and will be given without charge.
[Illustration: FIG. 99.—Egg-masses of the Tussock Moth.]
When to spray: In the case of chewing insects,
the latter part of May
is the time to spray.
The caterpillars hatch from their eggs, and
the elm leaf beetle leaves
its winter quarters at that time. In the
case of sucking insects,
the instructions will have to be more
specific, depending upon the
particular insect in question. Some
sucking insects can best be
handled in May or early June when their
young emerge, others can be
effectively treated in the fall or
winter when the trees are
dormant.
How to spray: Thoroughness is the essential principle
in all spraying.
In the case of leaf-eating
insects, this means covering every leaf
with the poison and applying
it to the under side of the leaves,
where the insects generally
feed. In the case of sucking insects,
thoroughness means an effort
to touch every insect with the spray.
It should be borne in mind
that the insect can be killed only when
hit with the chemical.
The solution should be well stirred, and
should be applied by means
of a nozzle that will coat every leaf
with a fine, mist-like spray.
Mere drenching or too prolonged an
application will cause the
solution to run off. Special precautions
should be taken with contact
poisons to see that the formula is
correct. Too strong a
solution will burn the foliage and tender
bark.
Spraying apparatus: There are various forms of
spraying apparatus in the
market, including small knapsack
pumps, barrel hand-pumps, and
gasolene and gas-power sprayers,
Figs. 97 and 98. Hose and nozzles
are essential accessories.
One-half inch, three-ply hose of the best
quality is necessary to stand
the heavy pressure and wear. Two
50-foot lengths is the usual
quantity required for use with a barrel
hand-pump. Each line
of hose should be supplied with a bamboo pole
10 feet long, having a brass
tube passed through it to carry the
nozzle. The Vermorel
nozzle is the best type to use. The cost of a
barrel outfit, including two
lines of hose, nozzles and truck,
should be from $30 to $40.
Power sprayers cost from $150 to $300 or
more.
Spraying material:
Arsenate of lead should be used
in the proportion Of 4 pounds of the
chemical to 50 gallons of
water. A brand of arsenate of lead
containing at least 14 per
cent of arsenic oxide with not more than
50 per cent of water should
be insisted upon. This spray may be used
successfully against caterpillars
and other leaf-eating insects in
the spring or summer.
Whale-oil soap should be used at
the rate of 11/2 pounds of the soap
to 1 gallon of hot water,
if applied to the tree in winter. As a
spray in summer, use 1 pound
of the soap to 5 gallons of water. This
treatment is useful for most
sucking insects.
Lime-sulfur wash is an excellent
material to use against sucking
insects, such as the San Jose
scale and other armored scales. The
application of a lime-sulfur
wash when put on during the dormant
season is not likely to harm
a tree and has such an excellent
cleansing effect that the
benefits to be derived in this direction
alone are often sufficient
to meet the cost of the treatment.
Lime-sulfur wash consists
of a mixture, boiled one hour, of 40
Kerosene emulsion consists of one-half
pound of hard soap, 1 gallon
of boiling water, and 2 gallons
of kerosene. It may be obtained in
prepared form and is then
to be used at the rate of one part of the
solution to nine parts of
water when applied in winter or to the
bark only in summer.
Use 2 gallons of the solution to a 40-gallon
barrel of water when applying
it to the leaves in the summer.
Kerosene emulsion is useful
as a treatment for scale insects.
Tobacco water should be prepared
by steeping one-half pound of
tobacco stems or leaves in
a gallon of boiling water and later
diluting the product with
5 to 10 gallons of water. It is
particularly useful for plant
lice in the summer.
The life history of an insect: In a general way,
all insects have four
stages of transformation before
a new generation is produced. It is
important to consider the
nature of these four stages in order that
the habits of any particular
insect and the remedies applicable in
combating it may be understood.
All insects develop from eggs, Fig. 99. The eggs then hatch into caterpillars or grubs, which is the larva stage, in which most insects do the greatest damage to trees. The caterpillars or grubs grow and develop rapidly, and hence their feeding is most ravenous. Following the larva stage comes the third or pupa stage, which is the dormant stage of the insect. In this stage the insect curls itself up under the protection of a silken cocoon like the tussock moth, or of a curled leaf like the brown-tail moth, or it may be entirely unsheltered like the pupa of the elm leaf beetle. After the pupa stage comes the adult insect, which may be a moth or a beetle.
A study of the four stages of any particular insect is known as a study of its life history. The important facts to know about the life history of an insect are the stage in which it does most of its feeding, and the period of the year in which this occurs. It is also important to know how the insect spends the winter in order to decide upon a winter treatment.
THE ELM LEAF BEETLE
Life history: The elm leaf beetle, Fig. 100,
is annually causing the
defoliation of thousands of
elm trees throughout the United States.
Several successive defoliations
are liable to kill a tree. The
insects pass the winter in
the beetle form, hiding themselves in
attics and wherever else they
can secure shelter. In the middle of
May when the buds of the elm
trees unfold, the beetles emerge from
their winter quarters, mate,
and commence eating the leaves, thus
producing little holes through
them. While this feeding is going on,
the females deposit little,
bright yellow eggs on the under side of
the leaves, which soon hatch
into small larvae or grubs. The grubs
then eat away the soft portion
of the leaf, causing it to look like
lacework. The grubs become
full grown in twenty days, crawl down to
the base of the tree, and
there transform into naked, orange-colored
pupae. This occurs in
the early part of August. After remaining in
the pupa stage about a week,
they change into beetles again, which
either begin feeding or go
to winter quarters.
Remedies: There are three ways of combating this
insect: First, by
spraying the foliage
with arsenate of lead in the latter part of
May while the beetles are
feeding, and repeating the spraying in
June when the larvae emerge.
The spraying method is the one most to
be relied on in fighting this
insect. A second, though less
important remedy, consists
in destroying the pupae when they
gather in large quantities
at the base of the tree. This may be
accomplished by gathering
them bodily and destroying them, or by
pouring hot water or a solution
of kerosene over them. In large
trees it may be necessary
to climb to the crotches of the main limbs
to get some of them.
The third remedy lies in gathering and
destroying the adult beetles
when found in their winter quarters.
The application of bands of
burlap or “tanglefoot,” or of other
substances often seen on the
trunks of elm trees is useless, since
these bands only prevent the
larvae from crawling down from the
leaves to the base and serve
to prevent nothing from crawling up.
Scraping the trunks of elm
trees is also a waste of effort.
[Illustration: FIG. 100.—The Elm Leaf Beetle. (After Dr. E.P. Felt.)
1. Egg cluster, enlarged. 1a. Single egg, greatly enlarged. 2. Young larva, enlarged. 3. Full grown larva, much enlarged. 4. Pupa, enlarged. 5. Overwintered beetle, enlarged. 6. Fresh, brightly colored beetle, enlarged. 7. Under surface of leaf showing larvae feeding. 8. Leaf eaten by larvae. 9. Leaf showing holes eaten by beetles.]
Life history: This insect appears in the form
of a red-headed,
yellow-colored caterpillar
during the latter part of May, and in
June and July. The caterpillars
surround themselves with silken
cocoons and change into pupae.
The mature moths emerge from the
cocoons after a period of
about two weeks, and the females, which
are wingless, soon deposit
their eggs on the bark of trees, on
twigs, fences, and other neighboring
objects. These eggs form white
clusters of nearly 350 individual
eggs each, and are very
conspicuous all winter, see
Fig. 101.
Remedies: There are two ways of combating this
insect: (1) By spraying
with arsenate of lead for
the caterpillars during the latter part of
May and early June. (2) By
removing and destroying the egg masses in
the fall or winter.
[Illustration: FIG. 101.—The Tussock Moth. (After Dr. E.P. Felt.)
1. Caterpillar. 2. Male moth. 3. Female moth laying eggs. 4 Cocoons. 5. Cast skins of caterpillar. 6. Work of young caterpillar. 7. Male pupa. 8 and 9. Girdled branches.]
Life history: This insect, imported from Europe
to this country in 1868,
has ever since proved a serious
enemy of most shade, forest, and
fruit trees in the New England
States. It even feeds on
evergreens, killing the trees
by a single defoliation.
The insect appears in the caterpillar stage from April to July. It feeds at night and rests by day. The mature caterpillar, which is dark in color, may be recognized by rows of blue and red spots along its back. After July, egg masses are deposited by the female moths on the bark of trees, and on leaves, fences, and other neighboring objects. Here they remain over the winter until they hatch in the spring. The flat egg masses are round or oval in shape, and are yellowish-brown in color. See Fig. 102.
Remedies: Spray for the caterpillars in June
with arsenate of lead and
apply creosote to the egg
masses whenever found.
Life history: This insect was introduced here
from Europe in 1890 and
has since done serious damage
to shade, forest, and fruit trees, and
to shrubs in the New England
States.
It appears in the caterpillar stage in the early spring and continues to feed on the leaves and buds until the last of June. Then the caterpillars pupate, the moths come out, and in July and August the egg clusters appear. These hatch into caterpillars which form nests for themselves by drawing the leaves together. Here they remain protected until the spring. See Fig. 103.
Remedies: Collect the winter nests from October
to April and burn them.
Also spray the trees for caterpillars
in early May and especially in
August with arsenate of lead.
[Illustration: FIG. 102.—The Gipsy Moth. (After F.W. Rane Mass. State Forester.)]
[Illustration: FIG. 103.—The Brown-tail Moth. (After F.W. Rane, Mass. State Forester.)]
[Illustration: FIG. 104.—Larva of the Leopard Moth.]
The caterpillars of this insect congregate in colonies and surround themselves with a web which often reaches the size of a foot or more in diameter. These webs are common on trees in July and August. Cutting off the webs or burning them on the twigs is the most practical remedy.
[Illustration: FIG. 105.—Branch Showing Work of the Leopard Moth Larva.]
Life history: This insect does its serious damage
in the grub form. The
grubs which are whitish in
color with brown heads, and which vary in
size from 3/8 of an inch to
3 inches in length (Fig. 104), may be
found boring in the wood of
the branches and trunk of the tree all
winter. Fig. 105.
The leopard moth requires two years to complete
its round of life. The
mature moths are marked with dark spots
resembling a leopard’s
skin, hence the name. Fig. 106. It is one
of
the commonest and most destructive
insects in the East and is
responsible for the recent
death of thousands of the famous elm
trees in New Haven and Boston.
Fig. 107.
[Illustration: FIG. 106.—The Leopard Moth.]
Remedies: Trees likely to be infested with this
insect should be
examined three or four times
a year for wilted twigs, dead branches,
and strings of expelled frass;
all of which may indicate the
presence of this borer.
Badly infested branches should be cut off
and burned. Trees so
badly infested that treatment becomes too
complicated should be cut
down and destroyed. Where the insects are
few and can be readily reached,
an injection of carbon bisulphide
into the burrow, the orifice
of which is then immediately closed
with soap or putty, will often
destroy the insects within.
[Illustration: FIG. 107.—Elm Tree Attacked by the Leopard Moth.]
Life history: This insect is a small brown or
black beetle in its mature
form and a small legless white
grub in its winter stage. The beetles
appear from June to August.
In July they deposit their eggs in the
outer sapwood, immediately
under the bark of the trunk and larger
branches. The eggs soon
hatch and the grubs feed on the living
tissue of the tree, forming
numerous galleries. The grubs pass the
winter in a nearly full-grown
condition, transform to pupae in May,
and emerge as beetles in June.
Remedies: The presence of the insect can be detected
by the small holes
in the bark of the trees and
the fine sawdust which is ejected from
these holes, when the insects
are active. It is important to
emphasize the advisability
of detecting the fine sawdust because
that is the best indication
of the actual operations of the hickory
bark borer. These holes,
however, will not be noticeable until the
insect has completed its transformation.
In summer, the infested
trees show wilted leaves and
many dead twigs. Holes in the base of
the petioles of these leaves
are also signs of the working of the
insect. Since the insect
works underneath the bark, it is
inaccessible for treatment
and all infested trees should be cut down
and burned, or the bark removed
and the insects destroyed. This
should be done before the
beetles emerge from the tree in June.
These often appear on the under side of the leaves of the beech, Norway maple, tulip tree, etc. They excrete a sweet, sticky liquid called “honey-dew,” and cause the leaves to curl or drop. Spraying with whale-oil soap solution formed by adding one pound of the soap to five gallons of water is the remedy.
Because trees have wants analogous to those of human beings, they also have diseases similar to those which afflict human beings. In many cases these diseases act like cancerous growths upon the human body; in some instances the ailment may be a general failing due to improper feeding, and in other cases it may be due to interference with the life processes of the tree.
How to tell an ailing tree: Whatever the cause,
an ailing tree will
manifest its ailment by one
or more symptoms.
A change of color in the leaves at a time when they should be perfectly green indicates that the tree is not growing under normal conditions, possibly because of an insufficiency of moisture or light or an overdose of foreign gases or salts. Withering of the leaves is another sign of irregularity in water supply. Dead tops point to some difficulty in the soil conditions or to some disease of the roots or branches. Spotted leaves and mushroom-like growths or brackets protruding from the bark as in Fig. 108, are sure signs of disease.
In attempting to find out whether a tree is healthy or not, one would therefore do well to consider whether the conditions under which it is growing are normal or not; whether the tree is suitable for the location; whether the soil is too dry or too wet; whether the roots are deprived of their necessary water and air by an impenetrable cover of concrete or soil; whether the soil is well drained and free from foreign gases and salts;Page 53
whether the tree is receiving plenty of light or is too much exposed; and whether it is free from insects and fungi.
If, after a thorough examination, it is found that the ailment has gone too far, it may not be wise to try to save the tree. A timely removal of a tree badly infested with insects or fungi may often be the best procedure and may save many neighboring trees from contagious infection. For this, however, no rules can be laid down and much will depend on the local conditions and the judgment and knowledge of the person concerned.
[Illustration: FIG. 108.—A Bracket Fungus (Elfvingia megaloma) on a Tulip Tree.]
Fungi as factors of disease: The trees, the shrubs
and the flowers with
which we are familiar are
rooted in the ground and derive their food
both from the soil and from
the air. There is, however, another
group of plants,—the
fungi,—the roots of which grow in trees
and
other plants and which obtain
their food entirely from the trees or
plants upon which they grow.
The fungi cannot manufacture their own
food as other plants do and
consequently absorb the food of their
host, eventually reducing
it to dust. The fungi are thus
disease-producing factors
and the source of most of the diseases of
trees.
When we can see fungi growing on a tree we may safely assume that they are already in an advanced state of development. We generally discover their presence when their fruiting bodies appear on the surface of the tree as shown in Fig 109. These fruiting bodies are the familiar mushrooms, puffballs, toadstools or shelf-like brackets that one often sees on trees. In some cases they spread over the surface of the wood in thin patches. They vary in size from large bodies to mere pustules barely visible to the naked eye. Their variation in color is also significant, ranging from colorless to black and red but never green. They often emulate the color of the bark, Fig. 110.
Radiating from these fruiting bodies into the tissues of the tree are a large number of minute fibers, comprising the mycelium of the fungus. These fibers penetrate the body of the tree in all directions and absorb its food. The mycelium is the most important part of the fungous growth. If the fruiting body is removed, another soon takes its place, but if the entire mycelium is cut out, the fungus will never come back. The fruiting body of the fungus bears the seed or spores. These spores are carried by the wind or insects to other trees where they take root in some wound or crevice of the bark and start a new infestation.
[Illustration: FIG. 109.—The Fruiting Body of a Fungus.]
The infestation will be favored in its growth if the spore can find plenty of food, water, warmth and darkness. As these conditions generally exist in wounds and cavities of trees, it is wise to keep all wounds well covered with coal tar and to so drain the cavities that moisture cannot lodge in them. This subject will be gone into more fully in the following two studies on “Pruning Trees” and “Tree Repair.”
[Illustration: FIG. 110.—The Birch-fungus rot. (Polyponis betulinus Fr.) Note the similarity in the color of the fruiting body and bark of the tree.]
While the majority of the fungi grow on the trunks and limbs of trees, some attack the leaves, some the twigs and others the roots. Some fungi grow on living wood some on dead wood and some on both. Those that attack the living trees are the most dangerous from the standpoint of disease.
The chestnut disease: The disease which is threatening
the destruction
of all the chestnut trees
in America is a fungus which has, within
recent years, assumed such
vast proportions that it deserves special
comment. The fungus is
known as Diaporthe parasitica (Murrill),
and was first observed in
the vicinity of New York in 1905. At that
time only a few trees were
known to have been killed by this
disease, but now the disease
has advanced over the whole chestnut
area in the United States,
reaching as far south as Virginia and as
far west as Buffalo.
Fig. 111 shows the result of the chestnut
disease.
The fungus attacks the cambium tissue underneath the bark. It enters through a wound in the bark and sends its fungous threads from the point of infection all around the trunk until the latter is girdled and killed. This may all happen within one season. It is not until the tree has practically been destroyed that the disease makes its appearance on the surface of the bark in the form of brown patches studded with little pustules that carry the spores. When once girdled, the tree is killed above the point of infection and everything above dies, while some of the twigs below may live until they are attacked individually by the disease or until the trunk below their origin is infected.
All species of chestnut trees are subject to the disease. The Japanese and Spanish varieties appear to be highly resistant, but are not immune. Other species of trees besides chestnuts are not subject to the disease.
[Illustration: FIG. 111.—Chestnut Trees Killed by the Chestnut Disease.]
There is no remedy or preventive for this disease. From the nature of its attack, which is on the inner layer of the tree, it is evident that all applications of fungicides, which must necessarily be applied to the outside of the tree, will not reach the disease. Injections are impossible and other suggested remedies, such as boring holes in the wood for the purpose of inserting chemicals, are futile.
The wood of the chestnut tree,
within three or four years after its
death, is still sound and
may be used for telephone and telegraph
poles, posts, railroad ties,
lumber and firewood.
Spraying for fungous diseases: Where a fungous
disease is attacking the
leaves, fruit, or twigs, spraying
with Bordeaux mixture may prove
effective. The application
of Bordeaux mixture is deterrent rather
than remedial, and should
therefore be made immediately before the
disease appears. The
nature of the disease and the time of treatment
can be determined without
cost, by submitting specimens of affected
portions of the plant for
analysis and advice to the State
Agricultural Experiment Station
or to the United States Department
of Agriculture.
Bordeaux mixture, the standard fungicide material, consists of a solution of 6 pounds of copper sulphate (blue vitriol) with 4 pounds of slaked lime in 50 gallons of water. It may be purchased in prepared form in the open market, and when properly made, has a brilliant sky-blue color. Spraying with Bordeaux mixture should be done in the fall, early spring, or early summer, but never during the period when the trees are in bloom.
FUNDAMENTAL PRINCIPLES
Trees are very much like human beings in their requirements, mode of life and diseases, and the general principles applicable to the care of one are equally important to the intelligent treatment of the other. The removal of limbs from trees, as well as from human beings, must be done sparingly and judiciously. Wounds, in both trees and human beings, must be disinfected and dressed to keep out all fungus or disease germs. Fungous growths of trees are similar to human cancers, both in the manner of their development and the surgical treatment which they require. Improper pruning will invite fungi and insects to the tree, hence the importance of a knowledge of fundamental principles in this branch of tree care.
[Illustration: FIG. 112.—A Tree Pruned Improperly and too Severely.]
Time: Too much pruning at one time should never
be practiced (Fig. 112),
and no branch should be removed
from a tree without good reason for
so doing. Dead and broken
branches should be removed as soon as
observed, regardless of any
special pruning season, because they are
dangerous, unsightly and carry
Proper cutting: All pruning should be commenced
at the top of the tree
and finished at the bottom.
A shortened branch (excepting in poplars
and willows, which should
be cut in closely) should terminate in
small twigs which may draw
the sap to the freshly cut wound; where a
branch is removed entirely,
the cut should be made-close and even
with the trunk, as in Fig.
113. Wherever there is a stub left after
cutting off a branch, the
growing tissue of the tree cannot cover it
and the stub eventually decays,
falls out and leaves a hole (see
Fig. 114), which serves to
carry disease and insects to the heart of
the tree. This idea of
close cutting cannot be over-emphasized.
Where large branches have to be removed, the splitting and ripping of the bark along the trunk is prevented by making one cut beneath the branch, about a foot or two away from the trunk, and then another above, close to the trunk.
[Illustration: FIG. 113.—Branches Properly Cut Close to the Trunk.]
Too severe pruning: In pruning trees, many people
have a tendency to cut
them back so severely as to
remove everything but the bare trunk and
a few of the main branches.
This process is known as “heading
back.” It is a
method, however, which should not be resorted to
except in trees that are very
old and failing, and even there only
with certain species, like
the silver maple, sycamore, linden and
elm. Trees like the sugar
maple will not stand this treatment at
all. The willow is a
tree that will stand the process very readily
and the Carolina poplar must
be cut back every few years, in order
to keep its crown from becoming
too tall, scraggy and unsafe.
[Illustration: FIG. 114.—A Limb Improperly Cut. Note how the stub is decaying and the resulting cavity is becoming diseased.]
Covering wounds: The importance of immediately
covering all wounds with
coal tar cannot be overstated.
If the wound is not tarred, the
exposed wood cracks, as in
Fig. 115, providing suitable quarters for
disease germs that will eventually
destroy the body of the tree.
Coal tar is by far preferable
to paint and other substances for
covering the wound. The
tar penetrates the exposed wood, producing
an antiseptic as well as a
protective effect. Paint only forms a
covering, which may peel off
[Illustration: FIG. 115.—Result of a Wound not Covered with Coal Tar. The exposed wood cracked and decay set in.]
Pruning shade trees: Here, the object is to produce
a symmetrical crown
and to have the lowest branches
raised from the ground sufficiently
high to enable pedestrians
to pass under with raised umbrellas. Such
pruning should, therefore,
necessarily be light and confined to the
low limbs and dead branches.
Pruning lawn trees: Here the charm of the tree
lies in the low reach of
the branches and the compactness
of the crown. The pruning should,
therefore, be limited to the
removal of dead and diseased branches
only.
Pruning forest trees: Forest trees have a greater
commercial value when
their straight trunks are
free from branches. In the forest, nature
generally accomplishes this
result and artificial pruning seldom has
to be resorted to. Trees
in the forest grow so closely together that
they shut out the sunlight
from their lower limbs, thus causing the
latter to die and fall off.
This is known as natural pruning. In
some European forests, nature
is assisted in its pruning by workmen,
who saw off the side branches
before they fall of their own accord;
but in this country such practice
would be considered too expensive,
hence it is seldom adopted.
Good tools are essential for quick and effective work in pruning. Two or three good saws, a pair of pole-shears, a pole-saw, a 16-foot single ladder, a 40-foot extension ladder of light spruce or pine with hickory rungs, a good pruning knife, plenty of coal tar, a fire-can to heat the tar, a pole-brush, a small hand brush and plenty of good rope comprise the principal equipment of the pruner.
1. Before climbing a tree, judge its general condition. The trunk of a tree that shows age, disease, or wood-destroying insects generally has its branches in an equally unhealthy condition.
2. The different kinds of wood naturally differ in their strength and elasticity. The soft and brash woods need greater precautions than the strong and pliable ones. The wood of all the poplars, the ailanthus, the silver maple and the chestnut, catalpa and willow is either too soft or too brittle to be depended upon without special care. The elm, hickory and oak have strong, flexible woods and are, therefore, safer than others. The red oak is weaker than the other oaks. The sycamore and beech have a tough, cross-grained wood which is fairly strong. The linden has a soft wood, while the ash and gum, though strong and flexible, are apt to split.
3. Look out for a limb that shows fungous growths. Every fungus sends fibers into the main body of the limb which draw out its sap. The interior of the branch then loses its strength and becomes like a powder. Outside appearances sometimes do not show the interior condition, but one should regard a fungus as a danger sign.
4. When a limb is full of holes or knots, it generally indicates that borers have been working all kinds of galleries through it, making it unsafe. The silver maple and sycamore maple are especially subject to borers which, in many cases, work on the under side of the branch so that the man in the tree looking down cannot see its dangerous condition.
5. A dead limb with the bark falling off indicates that it died at least three months before and is, therefore, less safe than one with its bark tightly adhering to it.
6. Branches are more apt to snap on a frosty day when they are covered with an icy coating than on a warm summer day.
7. Always use the pole-saw and pole-shears on the tips of long branches, and use the pole-hook in removing dead branches of the ailanthus and other brittle trees where it would be too dangerous to reach them otherwise.
8. Be sure of the strength of a branch before tying an extension ladder to it.
Where trees have been properly cared for from their early start, wounds and cavities and their subsequent elaborate treatment have no place. But where trees have been neglected or improperly cared for, wounds and cavities are bound to occur and early treatment becomes a necessity.
There are two kinds of wounds on trees: (1) surface wounds, which do not extend beyond the inner bark, and (2) deep wounds or cavities, which may range from a small hole in a crotch to the hollow of an entire trunk.
Surface wounds: Surface wounds (Fig. 116) are
due to bruised bark, and a
tree thus injured can no longer
produce the proper amount of foliage
or remain healthy very long.
The reason for this becomes very
apparent when one looks into
the nature of the living or active
tissue of a tree and notes
how this tissue becomes affected by such
injuries.
[Illustration: FIG. 116.—A Surface Wound Properly Freed from Decayed Wood and Covered with Coal Tar.]
This living or active tissue is known as the “cambium layer,” and is a thin tissue situated immediately under the bark. It must completely envelop the stem, root and branches of the trees. The outer bark is a protective covering to this living layer, while the entire interior wood tissue chiefly serves as a skeleton or support for the tree. The cambium layer is the real, active part of the tree. It is the part which transmits the sap from the base of the tree to its crown; it is the part which causes the tree to grow by the formation of new cells,Page 59
piled up in the form of rings around the heart of the tree; and it is also the part which prevents the entrance of insects and disease to the inner wood. From this it is quite evident that any injury to the bark, and consequently to this cambium layer alongside of it, will not only cut off a portion of the sap supply and hinder the growth of the tree to an extent proportional to the size of the wound, but will also expose the inner wood to the action of decay. The wound may, at first, appear insignificant, but, if neglected, it will soon commence to decay and thus to carry disease and insects into the tree. The tree then becomes hollow and dangerous and its life is doomed.
Injury to the cambium layer, resulting in surface wounds, may be due to the improper cutting of a branch, to the bite of a horse, to the cut of a knife or the careless wielding of an axe, to the boring of an insect, or to the decay of a fungous disease. (See Fig. 117.) Whatever the cause, the remedy lies in cleaning out all decayed wood, removing the loose bark and covering the exposed wood with coal tar.
In cutting off the loose bark, the edges should be made smooth before the coal tar is applied. Loose bark, put back against a tree, will never grow and will only tend to harbor insects and disease. Bandages, too, are hurtful because, underneath the bandage, disease will develop more rapidly than where the wound is exposed to the sun and wind. The application of tin or manure to wounds is often indulged in and is equally injurious to the tree. The secret of all wound treatment is to keep the wound smooth, clean to the live tissue, and well covered with coal tar.
The chisel or gouge is the best tool to employ in this work. A sharp hawk-billed knife will be useful in cutting off the loose bark. Coal tar is the best material for covering wounds because it has both an antiseptic and a protective effect on the wood tissue. Paint, which is very often used as a substitute for coal tar, is not as effective, because the paint is apt to peel in time, thus allowing moisture and disease to enter the crevice between the paint and the wood.
[Illustration: FIG. 117.—A Neglected Surface Wound. Note the rough surface of the wound, the want of a coal tar covering and the fungous growth that followed.]
Cavities: Deep wounds and cavities are generally
the result of stubs
that have been permitted to
rot and fall out. Surface wounds allowed
to decay will deepen in course
of time and produce cavities.
Cavities in trees are especially
susceptible to the attack of
disease because, in a cavity,
there is bound to exist an
accumulation of moisture.
With this, there is also considerable
darkness and protection from
wind and cold, and these are all ideal
conditions for the development
of disease.
The successful application
of a remedy, in all cavity treatment,
hinges on this principal condition—that
all traces of disease
shall be entirely eliminated
before treatment is commenced.
Fungous diseases attacking a cavity produce a mass of fibers, known as the “mycelium,” that penetrate the body of the tree or limb on which the cavity is located. In eliminating disease from a cavity, it is, therefore, essential to go beyond the mere decaying surface and to cut out all fungous fibers that radiate into the interior of the tree. Where these fibers have penetrated so deeply that it becomes impossible to remove every one of them, the tree or limb thus affected had better be cut down. (Fig. 118.) The presence of the mycelium in wood tissue can readily be told by the discolored and disintegrated appearance of the wood.
The filling in a cavity, moreover, should serve to prevent the accumulation of water and, where a cavity is perpendicular and so located that the water can be drained off without the filling, the latter should be avoided and the cavity should merely be cleaned out and tarred. (Fig. 116.) Where the disease can be entirely eliminated, where the cavity is not too large, and where a filling will serve the practical purpose of preventing the accumulation of moisture, the work of filling should be resorted to.
[Illustration: FIG. 118.—A Cavity Filled in a Tree that Should Have Been Cut Down. Note how the entire interior is decayed and how the tree fell apart soon after treatment.]
Filling should be done in the following manner: First, the interior should be thoroughly freed from diseased wood and insects. The chisel, gouge, mall and knife are the tools, and it is better to cut deep and remove every trace of decayed wood than it is to leave a smaller hole in an unhealthy state. The inner surface of the cavity should then be covered with a coat of white lead paint, which acts as a disinfectant and helps to hold the filling. Corrosive sublimate or Bordeaux mixture may be used as a substitute for the white lead paint. A coat of coal tar over the paint is the next step. The cavity is then solidly packed with bricks, stones and mortar as in Fig. 119, and finished with a layer of cement at the mouth of the orifice. This surface layer of cement should not be brought out to the same plane with the outer bark of the tree, but should rather recede a little beyond the growing tissue (cambium layer) which is situated immediately below the bark, Fig. 120. In this way the growing tissue will be enabled to roll over the cement and to cover the whole cavity if it be a small one, or else to grow out sufficiently to overlap the filling and hold it as a frame holds a picture. The cement is used in mixture with sand in the proportion of one-third of cement to two-thirds of sand. When dry, the outer layer of cement should be covered with coal tar to prevent cracking.
[Illustration: FIG. 119.—A Cavity in the Process of being Filled.]
[Illustration: FIG. 120—The Same Cavity Properly Filled.]
Trees that tend to split: Certain species of
trees, like the linden and
elm, often tend to split,
generally in the crotch of several limbs
and sometimes in a fissure
along the trunk of the tree. Midwinter is
the period when this usually
occurs and timely action will save the
tree. The remedy lies
in fastening together the various parts of the
tree by means of bolts or
chains.
A very injurious method of accomplishing this end is frequently resorted to, where each of the branches is bound by an iron band and the bands are then joined by a bar. The branches eventually outgrow the diameter of the bands, causing the latter to cut through the bark of the limbs and to destroy them.
Another method of bracing limbs together consists in running a single bolt through them and fastening each end of the bolt with a washer and nut. This method is preferable to the first because it allows for the growth of the limbs in thickness.
[Illustration: FIG. 121.—Diagram Showing the Triple-bar Method of Fastening Limbs.]
A still better method, however, consists in using a bar composed of three parts as shown in Fig. 121. Each of the two branches has a short bolt passed through it horizontally, and the two short bolts are then connected by a third bar. This arrangement will shift all the pressure caused by the swaying of the limbs to the middle connecting-bar. In case of a windstorm, the middle bar will be the one to bend, while the bolts which pass through the limbs will remain intact. The outer ends of the short bolts should have their washers and nuts slightly embedded in the wood of the tree, so that the living tissue of the tree may eventually grow over them in such a way as to hold the bars firmly in place and to exclude moisture and disease. The washers and nuts on the inner side of the limbs should also be embedded.
A chain is sometimes advantageously substituted for the middle section of the bar and, in some cases, where more than two branches have to be joined together, a ring might take the place of the middle bar or chain.
Bolts on a tree detract considerably from its natural beauty and should, therefore, be used only where they are absolutely necessary for the safety of the tree. They should be placed as high up in the tree as possible without weakening the limbs.
FORESTRY
Although Forestry is not a new idea but, as a science and an art, has been applied for nearly two thousand years, there are many persons who still need an explanation of its aims and principles.
Forestry deals with the establishment, protection and utilization of forests.
By establishment, is meant the planting of new forests and the cutting of mature forests, in such a way as to encourage a natural growth of new trees without artificial planting or seeding. The planting may consist of sowing seed, or of setting out young trees. The establishment of a forest by cutting may consist of the removal of all mature trees and dependence upon the remaining stumps to reproduce the forest from sprouts, or it may consist of the removal of only a portion of the mature trees, thus giving the young seedlings on the ground room in which to grow.
By protection, is meant the safeguarding of the forest from fire, wind, insects, disease and injury for which man is directly responsible. Here, the forester also prevents injury to the trees from the grazing and browsing of sheep and goats, and keeps his forest so well stocked that no wind can uproot the trees nor can the sun dry up the moist forest soil.
[Illustration: FIG. 122.—A Forest of Bull Pine Cut on Forestry Principles. (Photograph taken on the Black Hills National Forest, South Dakota.)]
By utilization, is meant the conservative and intelligent harvesting of the forest, with the aim of obtaining the greatest amount of product from a given area, with the least waste, in the quickest time, and without the slightest deterioration of the forest as a whole. The forester cuts his mature trees, only, and generally leaves a sufficient number on the ground to preserve the forest soil and to cast seed for the production of a new crop. In this way, he secures an annual output without hurting the forest itself. He studies the properties and values of the different woods and places them where they will be most useful. He lays down principles for so harvesting the timber and the by-products of the forest that there will be the least waste and injury to the trees which remain standing. He utilizes the forest, but does not cut enough to interfere with the neighboring water-sheds, which the forests protect.
[Illustration: 123.—A White Pine Plantation, in Rhode Island, Where the Crowns of the Trees Have Met. The trees are fifteen years old and in many cases every other tree had to be removed.]
Forestry, therefore, deals with a vast and varied mass of information, comprising all the known facts relating to the life of a forest. It does not deal with the individual tree and its planting and care,—that would be arboriculture. Nor does it consider the grouping of trees for aesthetic effect,—that would be landscape gardening. It concerns itself with the forest as a community of trees and with the utilization of the forest on an economic basis.
Each one of these activities in Forestry is a study in itself and involves considerable detail, of which the reader may obtain a general knowledge in the following pages. For a more complete discussion, the reader is referred to any of the standard books on Forestry.
The life and nature of a forest: When we think
of a forest we are apt to
think of a large number of
individual trees having no special
relationship to each other.
Closer observation, however, will reveal
that the forest consists of
a distinct group of trees, sufficiently
dense to form an unbroken
canopy of tops, and that, where trees grow
so closely together, they
become very interdependent. It is this
interdependence that makes
the forest different from a mere group of
trees in a park or on a lawn.
In this composite character, the
forest enriches its own soil
from year to year, changes the climate
within its own bounds, controls
the streams along its borders and
supports a multitude of animals
and plants peculiar to itself. This
communal relationship in the
life history of the forest furnishes a
most interesting story of
struggle and mutual aid. Different trees
have different requirements
with regard to water, food and light.
Some need more water and food
than others, some will not endure much
shade, and others will grow
in the deepest shade. In the open, a
tree, if once established,
can meet its needs quite readily and,
though it has to ward off
a number of enemies, insects, disease and
windstorm—its struggle
for existence is comparatively easy. In the
forest, the conditions are
different. Here, the tree-enemies have to
be battled with, just as in
the open, and in addition, instead of
there being only a few trees
on a plot of ground, there are
thousands growing on the same
area, all demanding the same things
out of a limited supply.
The struggle for existence, therefore,
becomes keen, many falling
behind and but few surviving.
[Illustration: FIG. 124.—Measuring the Diameter of a Tree and Counting its Annual Rings.]
This struggle begins with the seed. At first there are thousands of seeds cast upon a given area by the neighboring trees or by the birds and the winds. Of these, only a few germinate; animals feed on some of them, frost nips some and excessive moisture and unfavorable soil conditions prevent others from starting. The few successful ones soon sprout into a number of young trees that grow thriftily until their crowns begin to meet. When the trees have thus met, the struggle is at its height. The side branches encroach upon each other (Fig. 123), shut out the light without which the branches cannot live, and finally kill each other off. The upper branches vie with one another for light, grow unusually fast, and the trees increase in height with special rapidity. This is nature’s method of producing clear, straight trunks which are so desirable for poles and large timber. In this struggle for dominance, some survive and tower above the others, but many become stunted and fail to grow, while the majorityPage 64
become entirely overtopped and succumb in the struggle; see Fig. 139.
But in this strife there is also mutual aid. Each tree helps to protect its neighbors against the danger of being uprooted by the wind, and against the sun, which is liable to dry up the rich soil around the roots. This soil is different from the soil on the open lawn. It consists of an accumulation of decayed leaves mixed with inorganic matter, forming, together, a rich composition known as humus. The trees also aid each other in forming a close canopy that prevents the rapid evaporation of water from the ground.
The intensity of these conditions will vary a great deal with the composition of the forest and the nature and habits of the individual trees. By composition, or type of forest, is meant the proportion in which the various species of trees are grouped; i.e., whether a certain section of woodland is composed of one species or of a mixture of species. By habit is meant the requirements of the trees for light, water and food.
[Illustration: FIG. 125.—Mountain Slopes in North Carolina Well Covered with Forests.]
Some trees will grow in deep
shade while others will demand the
open. In the matter of
water and food, the individual requirements
of different trees are equally
marked.
The natural rapidity of growth of different species is also important, and one caring for a forest must know this rate of growth, not only as to the individual species, but also with respect to the forest as a whole. If he knows how fast the trees in a forest grow, both in height and diameter, he will know how much wood, in cubic feet, the forest produces in a year, and he can then determine how much he may cut without decreasing the capital stock. The rate of growth is determined in this way: A tree is cut and the rings on the cross-section surface are counted and measured; see Fig. 124. Each ring represents one year’s growth. The total number of rings will show the age of the tree. By a study of the rings of the various species of trees on a given plot, the rate of growth of each species in that location can be ascertained and, by knowing the approximate number of trees of each species on the forest area, the rate of growth of the whole forest for any given year can be determined.
[Illustration: FIG. 126.—Bottom Lands Buried in Waste from Deforested Mountains. Wu-t’ai-shan, Shan-si Province, China.]
[Illustration: FIG. 127.—Eroded Slope in Western North Carolina.]
Forests prevent soil erosion and floods: Forests
help to regulate the
flow of streams and prevent
floods. Most streams are bordered by
vast tracts of forest growths.
The rain that falls on these forest
areas is absorbed and held
by the forest soil, which is permeated
with decayed leaves, decayed
wood and root fibers. The forest floor
[Illustration: FIG. 128.—Flood in Pittsburgh, Pa.]
Where the soil is allowed to wash off, frequent floods are inevitable. Rain which falls on bare slopes is not caught by the crowns of trees nor held by the forest floor. It does not sink into the ground as readily as in the forest. The result is that a great deal of water reaches the streams in a short time and thus hastens floods. At other periods the streams are low because the water which would have fed them for months has run off in a few days. The farms are the first to suffer from the drouths that follow and, during the period of floods, whole cities are often inundated. Fig. 128 shows such a scene. The history of Forestry is full of horrible incidents of the loss of life and property from floods which are directly traceable to the destruction of the local forests and, on the other hand, there are many cases on record where flood conditions have been entirely obviated by the planting of forests. France and Germany have suffered from inundations resulting from forest devastation and, more than a hundred years ago, both of these countries took steps to reforest their mountain slopes, and thereby to prevent many horrible disasters.
[Illustration: FIG. 129.—Planting a Forest with Seedling Trees on the Nebraska National Forest. The man on the right is placing the tree in a slit just made with the spade. The man on the left is shoveling the dry sand from the surface before making the slit for the tree.]
[Illustration: FIG. 130.—Diagrammatic Illustration of a Selection Forest.]
How forests are established: New forests may
be started from seed or
from shoots, or suckers.
If from seed, the process may be carried on
in one of three ways:
First, by sowing the seed directly on the land.
Second, by first raising young trees in nurseries and later setting them out in their permanent locations in the forest. This method is applicable where quick results are desired, where the area is not too large, or in treeless regions and large open gaps where there is little chance for new trees to spring up from seed furnished by the neighboring trees. It is a method extensively practiced abroad where some of the finest forests are the result. The U.S. government, as well as many of the States, maintain forest-tree nurseries where millions of little trees are grown from seed and planted out on the National and State forests. Fig. 129 shows men engaged in this work. The fundamental principles of starting and maintaining a nursery have already been referred to in the chapter on “What Trees to Plant and How.”
The third method of establishing a forest from seed is by cutting the trees in the existing forest so that the seed falling from the remaining trees will, with the addition of light and space, readily take root and fill in the gaps with a vigorous growth of trees, without artificial seeding or planting. This gives rise to several methods of cutting or harvesting forests for the purpose of encouraging natural reproduction. The cutting may extend to single trees over the whole area or over only a part of the whole area. Where the cutting is confined to single trees, the system is known as the “Selection System,” because the trees are selected individually, with a view to retaining the best and most vigorous stock and removing the overcrowding specimens and those that are fully mature or infested with disease or insects.
Fig. 130 is a diagrammatic illustration of the operation of this system. In another system the cutting is done in groups, or in strips, and the number of areas of the groups or strips is extended from time to time until the whole forest is cleared. This system is illustrated in Fig. 131. Still another method consists in encouraging trees which will thrive in the shade, such as the beech, spruce and hemlock, to grow under light-demanding trees like the pine. This system presents a “two-storied” forest and is known by that name. The under story often has to be established by planting.
[Illustration: FIG. 131.—Diagrammatic Illustration of the Group or Strip System.]
In the system of reproducing forests from shoots or suckers, all trees of a certain species on a given area are cut off and the old stumps and roots are depended upon to produce a new set of sprouts, the strongest of which will later develop into trees. The coniferous trees do not lend themselves at all to this system of treatment, and, among the broadleaf trees, the species vary in their ability to sprout. Some, like the chestnut and poplar, sprout profusely; others sprout very little.
How forests are protected: Forestry also tries
to protect the forests
from many destructive agencies.
Wasteful lumbering and fire are the
worst enemies of the forest.
Fungi, insects, grazing, wind, snow and
floods are the other enemies.
[Illustration: FIG. 132.—The Result of a Forest Fire. The trees, lodgepole pine and Englemann spruce, are all dead and down. Photograph taken in the Colorado National Forest, Colorado.]
By wasteful lumbering is meant that the forest is cut with no regard for the future and with considerable waste in the utilization of the product. Conservative lumbering, which is the term used by foresters to designate the opposite of wasteful lumbering, will be described more fully later in this study.
Protection from fire is no less important than protection from wasteful lumbering. Forest fires are very common in this country and cause incalculable destruction to life and property; see Fig. 132. From ten to twelve million acres of forest-land are burnt over annually and the timber destroyed is estimated at fifty millions of dollars. The history of Forestry abounds in tales of destructive fires, where thousands of persons have been killed or left destitute, whole towns wiped out, and millions of dollars in property destroyed. In most cases, these uncontrollable fires started from small conflagrations that could readily, with proper fire-patrol, have been put out.
There are various ways of fighting fires, depending on the character of the fire,—whether it is a surface fire, burning along the surface layer of dry leaves and small ground vegetation, a ground fire, burning below the surface, through the layer of soil and vegetable matter that generally lines the forest floor, or a top fire, burning high up in the trees.
When the fire runs along the surface only, the injury extends to the butts of the trees and to the young seedlings. Such fires can be put out by throwing dirt or sand over the fire, by beating it, and, sometimes, by merely raking the leaves away.
Ground fires destroy the vegetable
mold which the trees need for
their sustenance. They
progress slowly and kill or weaken the roots
of the trees.
[Illustration: FIG. 133.—A Top Fire near Bear Canyon, Arizona.]
Top fires, Fig. 133, are the most dangerous, destroying everything in their way. They generally develop from surface fires, though sometimes they are started by lightning. They are more common in coniferous forests, because the leaves of hardwoods do not burn so readily. Checking the progress of a top fire is a difficult matter. Some fires will travel as rapidly as five miles an hour, and the heat is terrific. The only salvation for the forest lies, in many cases, in a sudden downpour of rain, a change of wind, or some barrier which the fire cannot pass. A barrier of this kind is often made by starting another fire some distance ahead of the principal one, so that when the two fires meet, they will die out for want of fuel. In well-kept forests, strips or lanes, free from inflammable material, are often purposelyPage 68
made through the forest area to furnish protection against top fires. Carefully managed forests are also patrolled during the dry season so that fires may be detected and attacked in their first stages. Look-out stations, watch-towers, telephone-connections and signal stations are other means frequently resorted to for fire protection and control. Notices warning campers and trespassers against starting fires are commonly posted in such forests. (Fig. 143.)
[Illustration: FIG. 134.—Sheep Grazing on Holy Cross National Forest, Colorado. The drove consists of 1600 sheep, of which only part are shown in the photograph.]
The grazing of sheep, goats and cattle in the forest is another important source of injury to which foresters must give attention. In the West this is quite a problem, for, when many thousands of these animals pass through a forest (Fig. 134), there is often very little young growth left and the future reproduction of the forest is severely retarded. Grazing on our National Forests is regulated by the Government.
As a means of protection against
insects and fungi, all trees
infested are removed as soon
as observed and in advance of all
others, whenever a lumbering
operation is undertaken.
[Illustration: FIG. 135.—A Typical Montana Sawmill.]
How forests are harvested: Forestry and forest
preservation require that
a forest should be cut and
not merely held untouched. But it also
demands that the cutting shall
be done on scientific principles, and
that only as much timber shall
be removed in a given time as the
forest can produce in a corresponding
period. After the cutting, the
forest must be left in a condition
to produce another crop of
timber within a reasonable
time: see Fig. 122. These fundamental
requirements represent the
difference between conservative lumbering
and ordinary lumbering.
Besides insuring a future supply of timber,
conservative lumbering, or
lumbering on forestry principles, also
tends to preserve the forest
floor and the young trees growing on
it, and to prevent injury
to the remaining trees through fire,
insects and disease.
It provides for a working plan by which the
kind, number and location
of the trees to be cut are specified, the
height of the stumps is stipulated
and the utilization of the wood
and by-products is regulated.
Conservative lumbering provides that the trees shall be cut as near to the ground as possible and that they shall be felled with the least damage to the young trees growing near by. The branches of the trees, after they have been felled, must be cut and piled in heaps, as shown in Fig. 122, to prevent fire. When the trunks, sawed into logs, are dragged through the woods, care is taken not to break down the young trees or to injure the bark of standing trees. Waste in thePage 69
process of manufacture is provided against, uses are found for the material ordinarily rejected, and the best methods of handling and drying lumber are employed. Fig. 135 shows a typical sawmill capable of providing lumber in large quantities.
In the utilization of the by-products of the forest, such as turpentine and resin, Forestry has devised numerous methods for harvesting the crops with greater economy and with least waste and injury to the trees from which the by-products are obtained. Fig. 136 illustrates an improved method by which crude turpentine is obtained.
[Illustration: FIG. 136.—Gathering Crude Turpentine by the Cup and Gutter Method. This system, devised by foresters, saves the trees and increases the output.]
Forestry here and abroad: Forestry is practiced
in every civilized
country except China and Turkey.
In Germany, Forestry has attained,
through a long series of years,
a remarkable state of scientific
thoroughness and has greatly
increased the annual output of the
forests of that country.
In France, Switzerland, Austria, Hungary, Norway, Sweden, Russia and Denmark, Forestry is also practiced on scientific principles and the government in each of these countries holds large tracts of forests in reserve. In British India one finds a highly efficient Forest Service and in Japan Forestry is receiving considerable attention.
In the United States, the forest areas are controlled by private interests, by the Government and by the States. On privately owned forests, Forestry is practiced only in isolated cases. The States are taking hold of the problem very actively and in many of them we now find special Forestry Commissions authorized to care for vast areas of forest land reserved for State control. These Commissions employ technically trained foresters who not only protect the State forests, but also plant new areas, encourage forest planting on private lands and disseminate forestry information among the citizens. New York State has such a Commission that cares for more than a million acres of forest land located in the northern part of the State. Many other States are equally progressive.
The United States Government is the most active factor in the preservation of our forests. The Government to-day owns over two hundred million acres of forest land, set aside as National Forests. There are one hundred and fifty individual reserves, distributed as shown in Fig. 137 and cared for by the Forest Service, a bureau in the Department of Agriculture. Each of the forests is in charge of a supervisor. He has with him a professional forester and a body of men who patrol the tract against fire and the illegal cutting of timber. Some of the men are engaged in planting trees on the open areas and others in studying the important forest problems of the region. Fig. 138.
[Illustration: FIG. 137.—Map Showing Our National Forests.]
[Illustration: FIG. 138.—Government Foresters in Missouri Studying the Growth and Habits of Trees. They are standing in water three feet deep.]
Where cutting is to be done on a National Forest, the conditions are investigated by a technically trained forester and the cutting is regulated according to his findings. Special attention is given to discovering new uses for species of trees which have hitherto been considered valueless, and the demand upon certain rare species is lessened by introducing more common woods which are suitable for use in their place.
Aside from the perpetuation of the national forests, the U.S. Forest Service also undertakes such tree studies as lie beyond the power or means of private individuals. It thus stands ready to cooperate with all who need assistance.
Almost every farm, large private estate or park has a wooded area for the purpose of supplying fuel or for enhancing the landscape effect of the place. In most instances these wooded areas are entirely neglected or are so improperly cared for as to cause injury rather than good. In but very few cases is provision made for a future growth of trees after the present stock has gone. Proper attention will increase and perpetuate a crop of good trees just as it will any other crop on the farm, while the attractiveness of the place may be greatly enhanced through the intelligent planting and care of trees.
How to judge the conditions: A close examination
of the wooded area may
reveal some or all of the
following unfavorable conditions:
The trees may be so crowded that none can grow well. A few may have grown to large size but the rest usually are decrepit, and overtopped by the larger trees. They are, therefore, unable, for the want of light and space, to develop into good trees. Fig. 139 shows woodland in such condition.
[Illustration: FIG. 139.—Woodland which Needs Attention. The trees are overcrowded.]
There may also be dead and dying trees, trees infested with injurious insects and fungi and having any number of decayed branches. The trees may be growing so far apart that their trunks will be covered with suckers as far down as the ground, or there may be large, open gaps with no trees at all. Here the sun, striking with full force, may be drying up the soil and preventing the decomposition of the leaves. Grass soon starts to grow in these open spaces and the whole character of the woodland changes as shown in Figs. 140 and 141.
[Illustration: FIG. 140.—First Stage of Deterioration. The woodland is too open and grass has taken the place of the humus cover.]
Where any of these conditions exist, the woodland requires immediate attention. Otherwise, as time goes on, it deteriorates more and more, the struggle for space among the crowded and suppressed trees becomes more keen, the insects in the dying trees multiply and disease spreads from tree to tree. Under such conditions, the soil deteriorates and the older trees begin to suffer.
[Illustration: FIG. 141.—Second Stage of Deterioration. The Surface Soil of the Wooded Area Has Washed Away and the Trees Have Died.]
The attention required for
the proper care of woodland may be summed
up under the four general
heads of soil preservation, planting,
cutting, and protection.
Improvement by soil preservation: The soil in
a wooded area can best be
preserved and kept rich by
doing two things; by retaining the
fallen leaves on the ground
and by keeping the ground well covered
with a heavy growth of trees,
shrubs and herbaceous plants. The
fallen leaves decompose, mix
with the soil and form a dark-colored
material known as humus.
The humus supplies the tree with a
considerable portion of its
food and helps to absorb and retain the
moisture in the soil upon
which the tree is greatly dependent. A
heavy growth of trees and
shrubs has a similar effect by serving to
retain the moisture in the
soil.
Improvement by planting: The planting of new
trees is a necessity on
almost any wooded area.
For even where the existing trees are in
good condition, they cannot
last forever, and provision must be made
for others to take their place
after they are gone. The majority of
the wooded areas in our parks
and on private estates are not
provided with a sufficient
undergrowth of desirable trees to take
the place of the older ones.
Thus, also, the open gaps must be
planted to prevent the soil
from deteriorating.
Waste lands on farms which are unsuited for farm crops often offer areas on which trees may profitably be planted. These lands are sufficiently good in most cases to grow trees, thus affording a means of turning into value ground which would otherwise be worthless. It has been demonstrated that the returns from such plantations at the end of fifty years will yield a six per cent investment and an extra profit of $151.97 per acre, the expense totaling at the end of fifty years, $307.03. The value of the land is estimated at $4 per acre and the cost of the trees and planting at $7 per acre. The species figured on here is white pine, one of the best trees to plant from a commercial standpoint. With other trees, the returns will vary accordingly.
[Illustration: FIG. 142.—A Farm Woodlot.]
The usual idea that it costs a great deal to plant several thousand young trees is erroneous. An ordinary woodlot may be stocked with a well-selected number of young trees at a cost less than the price generally paid for a dozen good specimen trees for the front lawn. It is not necessary to underplant the woodlot with big trees. The existing big trees are there to give character to the forest and the new planting should be done principally as a future investment and as a means of perpetuating the life of the woodlot. Young trees are even more desirable for such planting than the older and more expensive ones. The young trees will adapt themselves to the local soil and climatic conditions more easily than the older ones. Their demand for food and moisture is more easily satisfied, and because of their small cost, one can even afford to lose a large percentage of them after planting.
The young plants should be
two-year-old seedlings or three-year-old
“transplants.”
Two-year-old seedlings are
trees that have been grown from the seed
in seed beds until they reach
that age. They run from two to fifteen
inches in height, depending
upon the species.
Three-year-old “transplants” have been grown from the seed in seed beds and at the end of the first or second year have been taken up and transplanted into rows, where they grow a year or two longer. They are usually a little taller than the two-year-old seedlings, are much stockier and have a better root system. For this reason, three-year-old transplants are a little more desirable as stock for planting. They will withstand drought better than seedlings.
The best results from woodland planting are obtained with native-grown material. Such stock is stronger, hardier and better acclimated. Foreign-grown stock is usually a little cheaper, owing to the fact that it has been grown abroad, under cheap labor conditions.
The trees may be purchased from reputable dealers, of whom there are many in this country. These dealers specialize in growing young trees and selling them at the low cost of three to ten dollars per thousand. In States in which a Forestry Commission has been inaugurated, there have also been established State nurseries where millions of little trees are grown for reforestation purposes. In order to encourage private tree planting, the Forestry Commissions are usually willing to sell some of these trees at cost price, under certain conditions, to private land owners. Inquiries should be made to the State Forestry Commission.
Great care must be taken to select the species most suitable for the particular soil, climatic and light conditions of the woodlot. The trees which are native to the locality and are found growing thriftily on the woodlot, are the ones that have proven their adaptability to the local conditions and should therefore be the principalPage 73
species used for underplanting. A list from which to select the main stock would, therefore, vary with the locality. In the Eastern States it would comprise the usual hardy trees like the red, pin and scarlet oaks, the beech, the red and sugar maples, the white ash, the tulip tree, sycamore, sweet gum and locust among the deciduous trees; the white, Austrian, red, pitch and Scotch pines, the hemlock and the yew among the conifers.
With the main stock well selected, one may add a number of trees and shrubs that will give to the woodland scene a pleasing appearance at all seasons. The brilliant autumnal tints of the sassafras, pepperidge, blue beech, viburnum, juneberry and sumach are strikingly attractive. The flowering dogwood along the drives and paths will add a charm in June as well as in autumn and an occasional group of white birch will have the same effect if planted among groups of evergreens. Additional undergrowth of native woodland shrubs, such as New Jersey tea, red-berried elder and blueberry for the Eastern States, will augment the naturalness of the scene and help to conserve the moisture in the soil.
Two or three years’ growth will raise these plants above all grass and low vegetation, and a sprinkling of laurel, rhododendron, hardy ferns and a few intermingling colonies of native wild flowers such as bloodroot, false Solomon’s seal and columbines for the East, as a ground cover will put the finishing touches to the forest scene.
As to methods of planting the little trees, the following suggestions may prove of value. As soon as the plants are received, they should be taken from the box and dipped in a thick puddle of water and loam. The roots must be thoroughly covered with the mud. Then the bundles into which the little trees are tied should be loosened and the trees placed in a trench dug on a slant. The dirt should be placed over the roots and the exposed parts of the plants covered with brush or burlap to keep away the rays of the sun.
When ready for planting, a few plants are dug up, set in a pail with thin mud at the bottom and carried to the place of planting. The most economical method of planting is for one man to make the holes with a mattock. These holes are made about a foot in diameter, by scraping off the sod with the mattock and then digging a little hole in the dirt underneath. A second man follows with a pail of plants and sets a single plant in this hole with his hands, see Fig. 129, making sure that the roots are straight and spread out on the bottom of the hole. The dirt should then be packed firmly around the plant and pressed down with the foot.
Improvement by cutting: The removal of certain
trees in a grove is often
necessary to improve the quality
of the better trees, increase their
growth, make the place accessible,
and enhance its beauty. Cutting
in a wooded area should be
Immediately after cutting all diseased and infested wood should be destroyed. The sound wood may be utilized for various purposes. The bigger logs may be sold to the local lumber dealers and the smaller material may be used for firewood. The remaining brush should be withdrawn from the woodlot to prevent fire during the dry summer months.
In marking trees for removal, a number of considerations are to be borne in mind besides the elimination of dead, diseased and suppressed trees. When the marker is working among crowding trees of equal height, he should save those that are most likely to grow into fine specimen trees and cut out all those that interfere with them. The selection must also favor trees which are best adapted to the local soil and climatic conditions and those which will add to the beauty of the place. In this respect the method of marking will be different from that used in commercial forestry, where the aim is to net the greatest profit from the timber. In pure forestry practice, one sees no value in such species as dogwood, ironwood, juneberry, sumac and sassafras, and will therefore never allow those to grow up in abundance and crowd out other trees of a higher market value. But on private estates and in park woodlands where beauty is an important consideration, such species add wonderful color and attractiveness to the forest scene, especially along the roads and paths, and should be favored as much as the other hardier trees. One must not mark too severely in one spot or the soil will be dried out from exposure to sun and wind. When the gaps between the trees are too large, the trees will grow more slowly and the trunks will become covered with numerous shoots or suckers which deprive the crowns of their necessary food and cause them to “die back.” Where the trees are tall and slim or on short and steep hillsides, it is also important to be conservative in marking in order that the stand may not be exposed to the dangers of windfall. No hard-and-fast rule can be laid down as to whatPage 75
would constitute a conservative percentage of trees to cut down. This depends entirely on the local conditions and on the exposure of the woodlot. But in general it is not well to remove more than twenty per cent of the stand nor to repeat the cutting on the same spot oftener than once in five or six years. The first cutting will, of course, be the heaviest and all subsequent cuttings will become lighter and lighter until the woodlot is put in good growing condition. On private estates and parks, where beauty is the chief aim, the woodland should be kept as natural, informal and as thick as possible. Where the woodland is cut up by many paths and drives, density of vegetation will add to the impression of depth and distance.
Protection: This subject has already been discussed
considerably in the
previous study on Forestry,
and here it becomes necessary merely to
add a few suggestions with
special reference to private and park
woodlands.
Guarding woodlands from fire is the most important form of protection. Surface fires are very common on small woodland holdings and the damage done to the standing vegetation is generally underestimated. An ordinary ground or surface fire on a woodland area will burn up the leaf-litter and vegetable mold, upon which the trees depend so much for food and moisture, and will destroy the young seedlings on the ground. Where the fire is a little more severe, the older trees are badly wounded and weakened and the younger trees are frequently killed outright. Insects and disease find these trees an easy prey, and all related forest conditions commence to deteriorate.
Constant watchfulness and readiness to meet any emergency are the keynote of effective fire protection. Notices similar to the one shown in Fig. 143 often help to prevent fires. It is also helpful to institute strict rules against dropping lighted matches or tobacco, or burning brush when the ground is very dry, or leaving smouldering wood without waiting to see that the fire is completely out. There should be many roads and foot-paths winding through the woodland in order that they may serve as checks or “fire lanes” in time of fire. These roads and paths should be kept free from brush and leaves and should be frequently patrolled. When made not too wide, unpretentious and in conformity with the natural surroundings, such drives and paths can become a very interesting feature of the place, winding through the woodland, exposing its charms and affording opportunity for pleasant driving and walking. The borders of the paths can be given special attention by placing the more beautiful native shrubs in prominent positions where they can lend increased attractiveness.
In case of fire, it should be possible to call for aid by telephone directly from the woodland and to find within easy reach the tools necessary to combat fire. It is also important to obtainPage 76
the co-operation of one’s neighbors in protecting the adjoining woodlands, because the dangers from insects, disease and fire threatening one bit of woodland area are more or less dependent upon the conditions in the adjoining woodland.
[Illustration: FIG. 143.—Poster Suitable for Private Woodlands and Forest Parks. The translations in Italian and Polish have been used by the writer in this particular instance to meet the local needs.]
As to other forms of protection, passing mention may be made of the importance of keeping out cattle, sheep and hogs from the woods, of eliminating all insects and disease, of keeping the ground free from brush and other inflammable material, of retaining on the ground all fallen leaves and keeping the forest well stocked with little trees and shrubs.
Forest lands may be exempted from taxation: In
New York and other States
there exists a State law providing
for exemption or reduction in
taxes upon lands which are
planted with forest trees or maintained
as wooded areas. The
object of the law is to encourage home forestry
and to establish fairness
in the agricultural land-tax law by
placing forest lands in the
same category with other crop-producing
lands. For detailed information
and a copy of the law, one should
address the local State Forestry
Commission.
OUR COMMON WOODS: THEIR IDENTIFICATION, PROPERTIES AND USES
Woods have different values for various practical purposes because of their peculiarities in structure. A knowledge of the structural parts of wood is therefore necessary as a means of recognizing the wood and of determining why one piece is stronger, heavier, tougher, or better adapted for a given service than another.
Structure of wood: If one examines a cross-section
of the bole of a
tree, he will note that it
is composed of several distinct parts, as
shown in Fig. 145. At
the very center is a small core of soft tissue
known as the pith.
It is of much the same structure as the pith of
cornstalk or elder, with which
all are familiar. At the outside is
the bark, which forms
a protective covering over the entire woody
system. In any but the
younger stems, the bark is composed of an
inner, live layer, and an
outer or dead portion.
Between the pith at the center and the bark at the outside is the wood. It will be noted that the portion next to the bark is white or yellowish in color. This is the sapwood. It is principally through the sapwood that the water taken in by the roots is carried up to the leaves. In some cases the sapwood is very thin and in others it is very thick, depending partly on the kind of tree, and partly on its age and vigor. The more leaves on a tree the more sapwood it must have to supply them with moisture.
[Illustration: FIG. 144.—Pine Wood. (Magnified 30 times.)]
Very young trees are all sapwood, but, as they get older, part of the wood is no longer needed to carry sap and it becomes heartwood. Heartwood is darker than the sapwood, sometimes only slightly, but in other instances it may vary from a light-brown color to jet black. It tends to fill with gums, resins, pigments and other substances, but otherwise its structure is the same as that of the sapwood.
[Illustration: FIG. 145.—Cross-section of Oak.]
The wood of all our common trees is produced by a thin layer of cells just beneath the bark, the cambium. The cambium adds new wood on the outside of that previously formed and new bark on the inside of the old bark. A tree grows most rapidly in the spring, and the wood formed at that time is much lighter, softer and more porous than that formed later in the season, which is usually quite hard and dense. These two portions, known as early wood or spring wood, and late wood or summer wood, together make up one year’s growth and are for that reason called annual rings. Trees such as palms and yucca do not grow in this way, but their wood is not important enough in this country to warrant a description.
[Illustration: FIG. 146.—White Oak Wood. (Magnified 20 times.)]
If the end of a piece of oak wood is examined, a number of lines will be seen radiating out toward the bark like the spokes in a wheel. These are the medullary rays. They are present in all woods, but only in a few species are they very prominent to the unaided eye. These rays produce the “flakes” or “mirrors” that make quartersawed (radially cut) wood so beautiful. They are thin plates or sheets of cells lying in between the other wood cells. They extend out into the inner bark.
While much may be seen with the unaided eye, better results can be secured by the use of a good magnifying glass. The end of the wood should be smoothed off with a very sharp knife; a dull one will tear and break the cells so that the structure becomes obscured. With any good hand lens a great many details will then appear which before were not visible. In the case of some woods like oak, ash, and chestnut, it will be found that the early wood contains many comparatively large openings, called pores, as shown in Figs. 146 and 147. Pores are cross-sections of vessels which are little tube-like elements running throughout the tree. The vessels are water carriers. A wood with its large pores collected into one row or in a single band is said to be ring-porous. Fig. 146 shows such an arrangement. A wood with its pores scattered throughout the year’s growth instead of collected in a ring is diffuse-porous. Maple, as shown in Fig. 152, is of this character.
[Illustration: FIG. 147.—Example of the Black Oak Group. (Quercus coccinea.) (Magnified 20 times.)]
All of our broadleaf woods
are either ring-porous or diffuse-porous,
though some of them, like
the walnut, are nearly half way between
the two groups.
If the wood of hickory, for example, be examined with the magnifying lens, it will be seen that there are numerous small pores in the late wood, while running parallel with the annual rings are little white lines such as are shown in Fig. 149. These are lines of wood parenchyma. Wood parenchyma is found in all woods, arranged sometimes in tangential lines, sometimes surrounding the pores and sometimes distributed over the cross-section. The dark, horn-like portions of hickory and oak are the woodfibers. They give the strength to wood.
In many of the diffuse-porous woods, the pores are too small to be seen with the unaided eye, and in some cases they are not very distinct even when viewed with a magnifier. It is necessary to study such examples closely in order not to confuse them with the woods of conifers.
The woods of conifers are quite different in structure from broadleaf woods, though the difference may not always stand out prominently. Coniferous woods have no pores, their rays are always narrow and inconspicuous, and wood parenchyma is never prominent. The woods of the pines, spruces, larches, and Douglas fir differ from those of the other conifers in having resin ducts, Fig. 144. In pines these are readily visible to the naked eye, appearing as resinous dots on cross-sections and as pin scratches or dark lines on longitudinal surfaces. The presence or absence of resin ducts is a very important feature in identifying woods, hence it is very important to make a careful search for them when they are not readily visible.
How to identify a specimen of wood: The first
thing to do in identifying
a piece of wood is to cut
a smooth section at the end and note
(without the magnifier) the
color, the prominence of the rays and
pores, and any other striking
features. If the pores are readily
visible, the wood is from
a broadleaf tree; if the large pores are
collected in a ring it belongs
to the ring-porous division of the
broadleaf woods. If the
rays are quite conspicuous and the wood is
hard and heavy, it is oak,
as the key given later will show. Close
attention to the details of
the key will enable one to decide to
what group of oaks it belongs.
In most cases the structure will not stand out so prominently as in oak, so that it is necessary to make a careful study with the hand lens. If pores appear, their arrangement, both in the early wood and in the late wood, should be carefully noted; also whether the pores are open or filled with a froth-like substance known as tyloses. Wood parenchyma lines should be looked for, and if present, the arrangement of the lines should be noted.
[Illustration: FIG. 148.—(Magnified about 8 times.)]
If no pores appear under the magnifying lens, look closely for resin ducts. If these are found, note whether they are large or small, numerous or scattered, open or closed, lighter or darker than the wood. Note also whether the late wood is very heavy and hard, showing a decided contrast to the early wood, or fairly soft and grading into the early wood without abrupt change. Weigh the piece in your hand, smell a fresh-cut surface to detect the odor, if any, and taste a chip to see if anything characteristic is discoverable. Then turn to the following key:
I. WOODS WITHOUT PORES—CONIFERS OR SO-CALLED “SOFTWOODS”
A. Woods with resin ducts.
1. Pines. Fig. 144. Resin ducts numerous,
prominent, fairly evenly
distributed. Wood often
pitchy. Resinous odor distinct. Clear
demarcation between heart
and sapwood. There are two groups of
pines—soft and
hard.
(a) Soft Pines. Wood light, soft,
not strong, even-textured, very
easy to work. Change
from early wood to late wood is gradual and the
difference in density is not
great.
(b) Hard Pines. Wood variable but
typically rather heavy, hard and
strong, uneven textured, fairly
easy to work. Change from early wood
to late wood is abrupt and
the difference in density and color is
very marked, consequently
alternate layers of light and dark wood
show. The wood of nearly
all pines is very extensively employed in
construction work and in general
carpentry.
2. Douglas fir. Resin ducts less numerous
and conspicuous than in the
pines, irregularly distributed,
often in small groups. Odorless or
nearly so. Heartwood
and sapwood distinct. The wood is of two kinds.
In one the growth rings are
narrow and the wood is rather light and
soft, easy to work, reddish
yellow in color; in the other the growth
rings are wide, the wood is
rather hard to work, as there is great
contrast between the weak
early wood and the very dense late wood of
the annual rings.
Douglas fir is a tree of great
economic importance on the Pacific
Coast. The wood is much
like hard pine both in its appearance and
its uses.
3. Spruces. Resin ducts few, small, unevenly
distributed; appearing
mostly as white dots.
Wood not resinous; odorless. The wood is white
or very light colored with
a silky luster and with little contrast
between heart and sapwood.
It is a great deal like soft pine, though
lighter in color and with
much fewer and smaller resin ducts. The
wood is used for construction,
carpentry, oars, sounding boards for
musical instruments, and paper
pulp.
4. Tamarack. Resin ducts the same as in
the spruces. The color of the
heartwood is yellowish or
russet brown; that of the distinct sapwood
much lighter. The wood
is considerably like hard pine, but lacks the
resinous odor and the resin
ducts are much fewer and smaller.
The wood is used largely for
cross-ties, fence posts, telegraph and
telephone poles, and to a
limited extent for lumber in general
construction.
B. Woods without resin ducts.
1. Hemlock. The wood has a disagreeable,
rancid odor, is splintery, not
resinous, with decided contrast
between early and late wood. Color
light brown with a slight
tinge of red, the heart little if any
darker than the sapwood.
Hemlock makes a rather poor lumber which is
used for general construction,
also for cross-ties, and pulp.
2. Balsam fir. Usually odorless, not splintery,
not resinous, with
little contrast between early
and late wood. Color white or very
light brown with a pinkish
hue to the late wood. Heartwood little if
any darker than the sapwood.
Closely resembles spruce, from which it
can be distinguished by its
absence of resin ducts.
The wood is used for paper
pulp in mixture with spruce. Also for
general construction to some
extent.
3. Cypress. Odorless except in dark-colored
specimens which are somewhat
rancid. Smooth surface
of sound wood looks and feels greasy or waxy.
Moderate contrast between
early and late wood. Color varies from
straw color to dark brown,
often with reddish and greenish tinge.
Heartwood more deeply colored
than the sapwood but without distinct
boundary line.
Wood used in general construction,
especially in places where
durability is required; also
for shingles, cooperage, posts, and
poles.
4. Red Cedar. Has a distinct aromatic odor.
Wood uniform-textured; late
wood usually very thin, inconspicuous.
Color deep reddish brown or
purple, becoming dull upon
exposure; numerous minute red dots often
visible under lens. Sapwood
white. Red cedar can be distinguished
from all the other conifers
mentioned by the deep color of the wood
and the very distinct aromatic
odor.
Wood largely used for pencils;
also for chests and cabinets, posts,
and poles. It is very
durable in contact with the ground.
Western red cedar is
lighter, softer, less deeply colored and less
fragrant than the common Eastern
cedar. It grows along the Pacific
Coast and is extensively used
for shingles throughout the country.
5. Redwood. Wood odorless and tasteless,
uniform-textured, light and
weak, rather coarse and harsh.
Color light cherry. Close inspection
under lens of a small split
surface will reveal many little resin
masses that appear as rows
of black or amber beads which are
characteristic of this wood.
Redwood is confined to portions
of the Pacific Coast. It is used for
house construction, interior
finish, tanks and flumes, shingles,
posts, and boxes. It
is very durable.
A. Ring-porous.
1. Woods with a portion of the rays very large and conspicuous.
Oak. The wood of all of the oaks is heavy, hard,
and strong. They may be
separated into two groups.
The white oaks and the red or black oaks.
(a) White oaks. Pores in early wood
plugged with tyloses, collected in
a few rows. Fig. 146.
The transition from the large pores to the
small ones in the late wood
is abrupt. The latter are very small,
numerous, and appear as irregular
grayish bands widening toward the
outer edge of the annual ring.
Impossible usually to see into the
small pores with magnifier.
(b) Red or black oaks. Pores are
usually open though tyloses may
occur, Fig. 147; the early
wood pores are in several rows and the
transition to the small ones
in late wood is gradual. The latter are
fewer, larger and more distinct
than in white oak and it is
possible to see into them
with a hand lens.
The wood of the oaks is used
for all kinds of furniture, interior
finish, cooperage, vehicles,
cross-ties, posts, fuel, and
construction timber.
2. Woods with none of the rays large and conspicuous.
(a) Pores in late wood small and in radial lines, wood parenchyma in inconspicuous tangential lines.
Chestnut. Pores in early wood in a broad band,
oval in shape, mostly
free from tyloses. Pores
in late wood in flame-like radial white
patches that are plainly visible
without lens. Color medium brown.
Nearly odorless and tasteless.
Chestnut is readily separated from
oak by its weight and absence
of large rays; from black ash by the
arrangement of the pores in
the late wood; from sassafras by the
arrangement of the pores in
the late wood, the less conspicuous
rays, and the lack of distinct
color.
The wood is used for cross-ties,
telegraph and telephone poles,
posts, furniture, cooperage,
and tannin extract. Durable in contact
with the ground.
(b) Pores in late wood small, not radially arranged, being distributed singly or in groups. Wood parenchyma around pores or extending wing-like from pores in late wood, often forming irregular tangential lines.
1. Ash. Pores in early wood in a rather
broad band (occasionally
narrow), oval in shape, see
Fig. 148, tyloses present. Color brown
to white, sometimes with reddish
tinge to late wood. Odorless and
tasteless. There are
several species of ash that are classed as
white ash and one that is
called black or brown ash.
(a) White ash. Wood heavy, hard,
strong, mostly light colored except
in old heartwood, which is
reddish. Pores in late wood, especially
in the outer part of the annual
ring, are joined by lines of wood
parenchyma.
(b) Black ash. Wood more porous,
lighter, softer, weaker, and darker
colored than white ash.
Pores in late wood fewer and larger and
rarely joined by tangential
lines of wood parenchyma.
The wood of the ashes is used
for wagon and carriage stock,
agricultural implements, oars,
furniture, interior finish, and
cooperage. It is the
best wood for bent work.
[Illustration: FIG. 149.—Hickory Wood. (Magnified 45 times.)]
2. Locust. Pores in early wood in a rather
narrow band, round, variable
in size, densely filled with
tyloses. Color varying from golden
yellow to brown, often with
greenish hue. Very thin sapwood, white.
Odorless and almost tasteless.
Wood extremely heavy and hard,
cutting like horn. Locust
bears little resemblance to ash, being
harder, heavier, of a different
color, with more distinct rays, and
with the pores in late wood
in larger groups.
The wood is used for posts,
cross-ties, wagon hubs, and insulator
pins. It is very durable
in contact with the ground.
(c) Pores in late wood comparatively large, not in groups or lines. Wood parenchyma in numerous fine but distinct tangential lines.
[Illustration: FIG. 150.—Elm. (Magnified 25 times.)]
Hickory, Fig. 149. Pores in early wood moderately
large, not abundant,
nearly round, filled with
tyloses. Color brown to reddish brown;
thick sapwood, white.
Odorless and tasteless. Wood very heavy, hard,
and strong. Hickory is
readily separated from ash by the fine
tangential lines of wood parenchyma
and from oak by the absence of
large rays.
The wood is largely used for
vehicles, tool handles, agricultural
implements, athletic goods,
and fuel.
(d) Pores in late wood small and in conspicuous wavy tangential bands. Wood parenchyma not in tangential lines.
Elm. Pores in early wood not large and mostly
in a single row, Fig. 150
(several rows in slippery
elm), round, tyloses present. Color brown,
often with reddish tinge.
Odorless and tasteless. Wood rather heavy
and hard, tough, often difficult
to split. The peculiar arrangement
of the pores in the late wood
readily distinguishes elm from all
other woods except hackberry,
from which it may be told by the
fact that in elm the medullary
rays are indistinct, while they are
quite distinct in hackberry;
moreover, the color of hackberry is
yellow or grayish yellow instead
of brown or reddish brown as in
elm.
The wood is used principally
for slack cooperage; also for hubs,
baskets, agricultural implements,
and fuel.
[Illustration: FIG. 151.—(Magnified about 8 times.)]
B. Diffuse-porous.
1. Pores varying in size from rather large to minute, the largest being in the early wood. Intermediate between ring-porous and diffuse-porous.
Black Walnut. Color rich dark or chocolate brown.
Odor mild but
characteristic. Tasteless
or nearly so. Wood parenchyma in numerous,
fine tangential lines.
Wood heavy and hard, moderately stiff and
strong. The wood is used
principally for furniture, cabinets,
interior finish, moulding,
and gun stocks.
2. Pores all minute or indistinct, evenly distributed throughout annual ring.
(a) With conspicuously broad rays.
1. Sycamore. Fig. 151. Rays practically
all broad. Color light brown,
often with dark stripes or
“feather grain.” Wood of medium weight
and strength, usually cross-grained,
difficult to split.
The wood is used for general
construction, woodenware, novelties,
interior finish, and boxes.
2. Beech. With only a part of the rays broad,
the others very fine, Fig.
151. Color pale reddish
brown to white; uniform. Wood heavy, hard,
strong, usually straight-grained.
The wood is used for cheap
furniture, turnery, cooperage,
woodenware, novelties, cross-ties,
and fuel. Much of it is
distilled.
(b) Without conspicuously broad rays.
1. Cherry. Rays rather fine but very distinct.
Color of wood reddish
brown. Wood rather heavy,
hard, and strong.
The wood is used for furniture,
cabinet work, moulding, interior
finish, and miscellaneous
articles.
2. Maple, Fig. 152. With part of the rays
rather broad and conspicuous,
the others very fine.
Color light brown tinged with red. The wood of
the hard maple is very heavy,
hard and strong; that of the soft
maples is rather light, fairly
strong. Maple most closely resembles
birch, but can be distinguished
from it through the fact that in
maple the rays are considerably
more conspicuous than in birch.
The wood is used for slack
cooperage, flooring, interior finish,
furniture, musical instruments,
handles, and destructive
distillation.
3. Tulip-tree, yellow poplar or whitewood.
Rays all fine but distinct.
Color yellow or brownish yellow;
sapwood white. Wood light and soft,
straight-grained, easy to
work.
The wood is used for boxes,
woodenware, tops and bodies of vehicles,
interior finish, furniture,
and pulp.
4. Red or sweet gum. Rays all fine but somewhat
less distinct than in
tulip tree. Color reddish
brown, often with irregular dark streaks
producing a “watered”
effect on smooth boards; thick sapwood,
grayish white. Wood rather
heavy, moderately hard, cross-grained,
difficult to work.
The best grades of figured
red gum resemble Circassian walnut, but
the latter has much larger
pores unevenly distributed and is less
cross-grained than red gum.
The wood is used for finishing,
flooring, furniture, veneers, slack
cooperage, boxes, and gun
stocks.
[Illustration: FIG. 152.—Maple. (Magnified 25 times.)]
5. Black or sweet birch, Fig. 151. Rays
variable in size but all rather
indistinct. Color brown,
tinged with red, often deep and handsome.
Wood heavy, hard, and strong,
straight-grained, readily worked. Is
darker in color and has less
prominent rays than maple.
The wood is used for furniture,
cabinet work, finishing, and
distillation.
6. Cottonwood. Rays extremely fine and scarcely
visible even under lens.
Color pale dull brown or grayish
brown. Wood light, soft, not
strong, straight-grained,
fairly easy to work. Cottonwood can be
separated from other light
and soft woods by the fineness of its
rays, which is equaled only
by willow, which it rather closely
resembles. The wood is
largely used for boxes, general construction,
lumber, and pulp.
How to judge the quality of wood: To know the
name of a piece of wood
means, in a general way, to
know certain qualities that are common
to all other pieces of wood
of that species, but it does not explain
the special peculiarities
of the piece in question or why that
particular piece is more suitable
or unsuitable for a particular
purpose than another piece
of the same species. The mere
identification of the wood
does not explain why a particular piece
is tougher, stronger or of
darker color than another piece of the
same species or even of the
same tree. The reason for these special
differences lies in the fact
that wood is not a homogeneous material
like metal. Within the
same tree different parts vary in quality.
The heartwood is generally
heavier and of deeper color than the
sapwood. The butt is
superior to the top wood, and the manner in
which the wood was sawed and
dried will affect its quality. Knots,
splits, checks, and discoloration
due to incipient decay are defects
worth considering. Wood
that looks lusterless is usually defective,
because the lack of luster
is generally due to disease. Woods that
are hard wear best. Hardness
can be determined readily by striking
the wood with a hammer and
noting the sound produced. A clear,
ringing sound is a sign of
hardness. The strength of a piece of wood
can be judged by its weight
after it is well dried. Heavy woods are
usually strong. A large
amount of late wood is an indication of
strength and the production
of a clear sound when struck with a
hammer is also an evidence
of strength.
AN OUTDOOR LESSON ON TREES
The importance of nature study in the training of the child is now well recognized. The influences of such study from the hygienic, moral and aesthetic point of view are far reaching and cannot be expressed in dollars and cents. In his association with nature, the child is led to observe more closely and to know and to be fond of what is truly beautiful in life—beautiful surroundings, beautiful thoughts and beautiful deeds. He is inspired with reverence for law, order and truth because he sees it constantly reflected in all works of nature. The social instinct is highly developed and even the parents are often bettered through the agency of their children.
The only way, however, to study nature—especially plants—is to study it out of doors. Our present tendency to gather in cities demands the upbuilding influences of trips into the open in order to equip the child mentally and physically to face the world and its work with the strength and tenacity characteristic of the country-bred. Moreover, the study of objects rather than books is an axiom in modern education and here, too, we can readily see that the best way to study trees is to take the pupil to the trees. Such studies are more lasting than book study because they emphasize the spirit and the goal rather than the petty facts.
Educators and parents are now recognizing the value of outdoor trips for their children and are beginning to indulge in them quite frequently. In many instances teachers about to take out their children for a day have inquired of the writer how to go about giving a general field lesson when they reached the park or woodland. The purpose of this chapter is to answer such a question and yet it is evident that it cannot be answered completely. What to observe out doors and how to present one’s impressions is a broad question and varies with the knowledge and ability of the teacher as well as with the age and experience of the children. The how and the what in nature study is of greater import than the hard, dry facts and that must be left entirely to the teacher. A few suggestions, however, may not be amiss:
1. General observations with a view to character
building: First of all
it is important to remember
that the great value of all tree and
nature study is the inculcation
in the minds of the children of an
appreciation and love for
the beautiful. Inspiring them to love
trees generally means more
than teaching them to know trees. Mere
facts about trees taught in
an academic way are often no more
lasting than the formulae
in trigonometry which most of us have long
ago forgotten. The important
thing is that permanent results be left
and nothing else will produce
such lasting impressions as the study
of trees out of doors.
[Illustration: FIG. 153.—Trees Have Individuality.]
General observations about trees can be made by pointing out the beauty and character of the individual forms and branching, their harmony in their relations to each other as factors of a beautiful composition and the wealth of shades and colors in their leaves, bark and flowers. Compare, for instance, the intricate ramification of an American elm with the simple branching of a sugar maple, the sturdiness of a white oak with the tenderness of a soft maple, the wide spread of a beech with the slender form of a Lombardy poplar, the upward pointing branches of a gingko with the drooping form of a weeping willow. At close range, each of these trees reveals itself as an individual with a character quite its own. At little distance you may see them grouped together, subordinating their individuality and helping to blend into a beautiful composition with a character all its own. There is nothing more inspiring than the variety of greens in the spring foliage, the diversity of color in the spring blossoms and the wonderful display of autumnal tints offered by the sweet gum, sassafras, dogwood, black gum, red maple, sugar maple, scarlet oak, blue beech, sorrel tree, ash and gingko. The white bark of the gray birch, the dark bark of the black oak, the gray of the beech, the golden yellow of the mulberry and the mottled bark of the sycamore are interesting comparisons. The smooth bark of the mockernut hickory contrasts greatly with the shaggy bark of the shagbark hickory—members of the same family and yet how different. A wonderful opportunity is thus offered for a comparative study of human nature—individuality and community life, all reflected in trees.
With this preliminary study
and with the addition of some remarks on
the value of trees as health
givers and moral uplifters, the child
is interested and attracted.
The lesson so far has attained its aim.
2. Specific observations with a view to training
the observative powers:
The child’s training
in closeness of observation and scientific
precision may be the next
consideration. His enthusiasm will now
prompt him to lend his interest
for greater detail. We can teach him
to recognize a few of the
common trees by their general
characters—an American
elm by its fan-shaped form, a gray birch by
its white bark, a white pine
by the five needles to each cluster, a
horsechestnut by its opposite
branching and big sticky bud and a
willow by its drooping habit.
After that we may introduce, if the
age of the pupils justifies,
more details extending to greater
differences which distinguish
one species from another.
The lesson might continue by pointing out the requirements of trees for water and light. Find a tree on some slope where the roots are exposed and another which is being encroached upon by its neighbor, and show how in one case the roots travel in search of water and food and in the other the branches bend toward the light, growing more vigorously on that side. Compare the trees on the open lawn with those in the grove and show how those in the open have grown with branches near the ground while those in the woodland are slender, tall and free from branches to some distance above the ground. Point out the lenticels on the bark of birch and sweet cherry trees and explain how trees breathe. Compare this process with that of the human body. You may now come across an old stump and here you can point out the structure of the wood—the sapwood, cambium and bark. You can illustrate the annual rings and count the age of the tree. At another point you may find a tree with a wound or bruised bark and here you can readily make a closer study of the cambium layer and its manner of growth.
The adaptation of plants to the seasonal changes opens another interesting field of study for beginners. If the season is the fall or winter, note how the trees have prepared themselves for the winter’s cold by terminating the flow of sap, by dropping their leaves too tender to resist the winter’s cold, and by covering their buds with scales lined with down on the inside. Observe how the insects have spun for themselves silken nests or remain preserved in the egg state over the winter. If the season is spring or summer the opposite may be noted. See how everything turns to life; how the buds are opening, the leaves emerging, the sap running, seeds germinating and flowers blooming.
The soil conditions on the lawn and in the grove furnish another interesting feature of comparison and study. In the grove, you can demonstrate the decomposition of the fallen leaves, the formation of humus and its value to the tree. The importance of the forest soil as a conservator of water and its relation to stream flow and soil erosion can be brought out at this juncture. An eroded bank and a slope covered with trees and shrubs would provide excellent models for this study. A consideration of the economic value of the trees would also be in place.
3. Civic lessons reflected in trees: The
community life of trees in the
grove, their growth, struggles
for light and food and their mutual
aid can be brought out and
compared with the community life among
people. The trees may
here be seen struggling with each other for
light and food, forcing each
other’s growth upward, some winning out
and developing into stalwart
and thrifty specimens and others
becoming suppressed or entirely
killed. On the other hand they may
be seen helping each other
in their community growth by protecting
each other from windfall and
by contributing to the fertility of the
forest soil in dropping their
leaves and shading the ground so that
these fallen leaves may decompose
readily.
[Illustration: FIG. 154.—Trees also Grow in Communities.]
4. Enemies of trees: An old stump or tree
may be seen crumbling away
under the influence of fungi
and here the children may be shown the
effects of tree diseases both
as destroyers of life and as
up-builders, because fungi
turn to dust the living trees and build
up others by furnishing them
with the decomposed wood matter.
Insects too, may be invading the old dead tree, and something of their nature, habits and influences may be gone into. They may be shown as wood borers, leaf eaters, or sap suckers, all injurious to the tree. On the other hand they may be shown as seed disseminators and as parasites on other injurious insects; all benefactors.
Forest fires as an enemy of trees might be touched upon by noting how easily the leaves may be ignited and a surface fire started when the season is dry. Top and ground fires emanating from surface fires can then be readily explained.
[Illustration: FIG. 155.—Trees Blend Together to Form a Beautiful Composition.]
5. Expression: The pupils have by this time
been taught to feel the
beautiful, to observe carefully
and to reason intelligently and they
may now be trained to express
themselves properly. This may be
accomplished by asking them
to remember their observations and to
write about them in the classroom.
The lesson may be supplemented
with effective reading about
trees and forests. Interesting reading
matter of this sort can be
found in abundance in children’s readers,
in special books on the subject
and in Arbor Day Manuals published
by the various State Education
Departments.
6. Preparation: In order to save time looking
for objects of interest
and for the purpose of correlating
the various observations so that
all will follow in orderly
sequence, it is well for the teacher or
leader to go over the ground
beforehand and note the special
features of interest.
The various topics can then be given some
thought and a brief synopsis
can be drawn up to serve as a
memorandum and guide on the
trip.
It is also well to be provided with a hatchet to cut into some decayed stump, a trowel to dig up the forest soil, a knife for cutting off twigs and a hand reading glass for examining the structural parts of the various objects under observation. A camera is always a valuable asset because the photographs hung in the classroom become records of great interest to all participants.
7. Suggestions for forming tree clubs: A
good way to interest children
in trees and nature study
is to form, among them, a Tree Club. The
idea has been fully developed
in Brooklyn, N.Y., Newark, N.J., and
other cities and consists
of forming clubs of children in the public
Acer negundo, — platanoides, — polymorphum, — pseudoplatanus, — rubrum, — saccharinum, — saccharum, Aesculus hippocastanum, — rubicunda, Ailing tree, how to tell an, Air, influence of, Alternate branched trees, American beech, — elm, — larch, — linden, Annual rings, Aphides or plant lice, Apple rust, Arbor-vita and red cedar, description of, — (northern white cedar), Arsenate of lead, Ash, wood, — black, — white, Ash-leaf maple, Aspen, large-toothed, —, quaking, Austrian pine,
Bald cypress,
Balm of Gilead,
Balsam, fir,
—, poplar,
Bark,
Bark, how to prevent splitting when removing branches,
— or trunk, trees told by their,
Bass-wood,
Bean, Indian,
Beech, American,
—, blue, or hornbeam,
—, copper,
—, European,
— tree,
Beetle, elm leaf,
Betula alba,
— lutea,
— lenta,
— papyrifera,
— populifolia,
Bhotan pine,
Bigbud hickory,
Birch, black,
—, European white,
— fungus rot,
—, gray,
—, paper,
—, sweet,
— tree,
—, white,
—, yellow,
Bitternut hickory,
Black ash,
— birch,
— locust,
— oak,
— or sweet birch,
— spruce,
— walnut,
Blotches, leaf,
Blue beech, or hornbeam,
— spruce,
Bolting limbs,
Bordeaux mixture,
Borer, bronze-birch,
—, hickory bark,
—, linden,
—, locust,
—, sugar maple,
Boring insects,
Box-elder,
Bracing limbs, various methods of,
Bracket fungus,
Branches, dead and broken, removal of,
—, how to prevent bark splitting when removing,
Broadleaf or “hardwoods,”
Bronze-birch borer,
Brooklyn, N.Y.,
Broom hickory,
Brown hickory,
Brown-tail moth,
Buckeye,
Butternut,
Buttonball,
Buttonwood,
By-products of forests, utilization of,
Cambium layer,
Camperdown elm,
Care in selecting trees suitable for the soil,
Carolina poplar,
Carpinus caroliniana,
Castanea dentata,
Catalpa speciosa,
Caterpillars,
Caterpillars, leaf-eating,
—, spraying for,
Catkin,
Cattle grazing in forests a source of injury,
Cavities, fungous diseases attacking,
— how caused,
—, manner of filling,
Cedar apple,
—, white,
Celtis occidentalis,
Chamaecyparis thyoides,
Character building and trees,
Chestnut,
Dead and broken branches, removal of,
Deciduous trees,
Destroying injurious insects, methods of,
— pupae,
Developing disease, moisture a factor in,
Diaporthe parasitica,
Diffuse-porous woods,
Disease, fungi as factors of,
— moisture a factor in developing,
Dogwood, flowering,
Douglas fir,
Effect of heat on trees, Elkwood, Elm, —, American, —, Camperdown, —, cork, —, English, — leaf beetle, —, poplar, gingko and willow trees, told by their form, —, white, Enemies of trees, Enemy of trees, forest fires as an English elm, — hawthorn, — yew, European beech, — larch, — linden, — weeping birch, — white birch,
Fall webworm,
Fagus,
— americana,
— sylvatica,
Fern, maidenhair,
Fighting forest fires, various ways of,
Filling cavities, manner of,
Fire, guarding woodlands from,
Flowering dogwood,
Foliage, spraying,
Forest fires as an enemy of trees,
— —, various ways of fighting,
— lands, exemption from taxation,
—, life and nature of,
— trees, pruning,
Forestry in various countries,
—, what it is and what it does,
Forests, grazing cattle in, a source of injury,
Forest Service, U.S.,
—, harvesting,
—, harvesting of, to increase production,
—, how established,
—, how harvested,
—, how protected,
—, how they help to regulate streams and
prevent floods,
—, method of establishing,
—, planting, with seedling trees,
— prevent soil erosion,
—, protecting from destructive agencies,
—, safeguarding,
—, utilization of by-products,
Fraxinus americana,
— nigra,
Frost, effect of, on trees,
Fungi and insects, protection against,
— as factors of disease,
Fungous diseases attacking cavities,
— diseases, spraying for,
Fungus, fruiting body of,
Gingko biloba,
— or maidenhair tree,
Gipsy moth,
Gleditsia triacanthos,
Gloeosporium nervisequum,
Gray or white birch,
Grazing effect on forests,
Grove and lawn, study of soil conditions on,
Gum, red or sweet,
Gymnocladus dioicus,
Hackberry tree,
Hackmatack,
Hard maple,
— pines,
“Hardwoods,” or broadleaf trees,
Hardy catalpa,
Harvesting forests,
Harvesting of forests to increase production,
Hawthorn, English,
Healthy tree, conditions which indicate,
Heartwood,
Heat, effect of, on trees,
Hemlock,
— and spruce, description of,
Hickory,
— bark borer,
—, bigbud,
—, bitternut,
—, broom,
—, brown,
—, mockernut,
—, pignut,
—, shagbark,
—, shellbark,
—, whiteheart,
Hicoria alba,
— glabra,
— minima,
— ovata,
Honey locust,
Hop hornbeam,
Hornbeam, (blue beech),
Horsechestnut,
—, red,
Humus,
Hydrophytes,
Important insects,
Improperly pruned trees,
Indian bean,
Individuality of trees,
Insects and fungi, protection against,
—, boring,
—, chewing,
— galls,
—, important kinds of,
— injurious to trees,
—, leaf-eating,
—, methods of destroying injurious,
—, nature, habits and influences of,
—, sucking,
—, the four stages, or life history of,
Ironwood tree,
Italian or Lombardy poplar,
Japanese maple,
— umbrella pine,
Juglans cinerea,
— nigra,
Juniper,
Juniperus communis,
Juniperus virginiana,
Kerosene emulsion,
Knees, cypress,
Larch, American,
— and cypress, description of,
— European,
Large-toothed aspen,
Larix europaea,
Lawn and grove, study of soil conditions on,
Lawn trees,
— —, pruning,
Leaf blotches,
Leaf-eating caterpillars,
——, insect,
Leaves,
—, needle-shaped,
—, scale-like,
—, star-shaped,
Lenticels,
Leopard moth,
Lesson on trees, outdoor,
Light, influence of, on trees,
Limbs, various methods of bracing,
Lime-sulphur wash,
Lime-tree,
Linden, American,
— borer,
—, European,
Liquidambar styraciflua,
Liriodendron, tulipifers,
Location of trees, care to be exercised in,
Locust,
—, black,
— borer,
—, common,
—, honey,
— miner,
—, yellow,
Lombardy or Italian poplar,
Low juniper,
Magnolia acuminata, —, mountain, — soulangeana, —, Soulange’s, — tripetala, Magnolias, the, Maiden-hair fern, — or gingko tree, Maple wood, —, ash-leaf, —, hard, —, Japanese, —, Norway, — phenacoccus, —, red, —, rock, —, silver, —, soft, — sugar, — swamp, —, sycamore, —, white, Mesophytes, Method of covering wounds, Methods of destroying injurious insects, Mockernut hickory, Moisture a factor in developing disease, —, influence of, on trees, Moral influence of trees, Morus alba, — rubra, Moth, gipsy, —, leopard, Mountain magnolia, Mugho pine, Mulberry, red, —, white,
National forests,
Needle-shaped leaves,
Nettle tree,
Newark, N.J.,
Northern white cedar (arbor-vitae),
Norway maple,
— spruce,
Nursery, tree,
Oak, —, black, —, pin, —, red, —, scarlet, —, swamp white, —, white, —, yellow, Oaks and chestnut, Observations about trees, general, — and precision, child training in, Obtuse Japanese cypress, Opposite branched trees, Orange, Osage, Oriental spruce, — sycamore, Osage orange, Ostrya virginiana, Outdoor lesson on trees, Oyster-shell scale,
Paper birch,
Picea canadensis,
— excelsa,
— mariana,
— orientalis,
— parryana,
— pungens,
Pignut hickory,
Pin oak,
Pine, Austrian,
—, Bhotan,
—, Mugho,
—, red,
—, Scotch,
— trees,
— weevil, white,
—, white,
Pines,
Pinus Austriaca,
— excelsa,
— mughus,
— resinosa,
— rigida,
— strobus,
— sylvestris,
Pitch pine,
Pith,
Plane or sycamore tree,
Plant lice, or aphides,
— study, value of, for children,
— trees, how to,
Planting forests,
— forests with seedling trees,
— little trees, methods of,
—, improving woodland by,
— new trees,
— trees,
— — most economical method,
— — on land unsuitable for crops,
Plants, adaptation of, to seasonal changes,
Platanus occidentalis,
— orientalis,
Polyporus betulinus,
Poplar, balsam,
—, Carolina,
—, Lombardy or Italian,
—, silver,
—, tulip,
—, white,
—, yellow,
Populus alba,
— balsamifera,
— deltoides,
— grandidentata,
— nigra,
— tremuloides,
Pores in wood,
— small or indistinct,
— varying in size,
Poster for private woodlands,
Precautions against fire,
Protection against fungi and insects,
Pruning forest trees,
— lawn trees,
— shade trees,
—, tools used in,
—, too severe,
— trees, fundamental principles,
— —, time for,
Pussy willow,
Quaking aspen,
Quality of trees, how to judge,
Quality of wood, how to judge,
Quercus alba,
— palustris,
— platanoides,
— rubra,
— velutina,
Red cedar, — — and arbor-vitae, description of, — gum, — horsechestnut, — juniper, — maple, — mulberry, — oak, — pine, — or black oaks, — or sweet gum, Red spider, Redwood, Removal of dead and broken branches, — of trees, how to mark, Requirements of trees, Retinospora obtusa, Rhytisma acerinum, Ring-porous woods, Robinia pseudacacia, Rock maple, Roots, —, development of, —, protection of, from drying, Rust, apple,
Safeguarding forests,
Salix babylonica,
Salix discolor,
Saperda vestita,
Sapwood,
Sawfly,
Scale, cottony-maple,
—, oyster-shell,
Scale-like leaves,
Scarlet oak,
Sciadopitys verticillata,
Scolytus quadrispinosus,
Scotch pine,
Screening trees,
Season, influence of,
Seasons for spraying trees,
Seedling trees, planting forests with,
Shade trees, pruning,
Shagbark hickory,
Shellbark hickory,
Silver maple,
Tamarack,
Taxation, forest lands exempt from,
Taxodium distichum,
Taxus baccata,
Thuja occidentalis,
Tilia americana,
— microphylla,
Tobacco water,
Tools used in pruning,
Toxylon pomiferum,
Training a child to recognize trees,
— children in observation and precision,
Trametes pini,
Treating surface wounds,
Tree, ailing, how to tell an,
— and nature study, value of,
—, beech,
—, birch,
—, blue beech,
— climbers, suggestions for safety of,
— clubs, suggestions for forming,
—, coffee,
— diseases,
— diseases, effects of, as destroyers and
up-builders,
— growth, conditions for, in different
localities,
—, hackberry,
—, iron wood,
—, nettle,
— nursery, suggestions for,
—, plane,
— repair,
—, sycamore,
—, tulip,
—, weeping willow,
Trees and character building,
—, care of,
—, care to be exercised in location of,
—, civic lessons reflected in,
—, community life of,
—, coniferous,
—, crowding,
—, deciduous,
—, effect of frost on,
—, effect of heat on,
—, enemies of,
— for lawns,
— for screening,
— for streets,
— for woodland,
—, general observations about,
—, hickories, walnut, and butternut,
—, how to identify,
—, how to mark for removal,
—, how to plant,
—, how to spray,
—, improperly pruned,
—, individuality of
—, influence of light on,
—, influence of moisture on,
—, influence of soil on,
—, insects injurious to,
—, measuring diameter of,
—, methods of planting little,
—, methods of removing,
Ulmus americana,
— campestris,
Umbrella pine, Japanese,
— tree,
Value of plant study for children, — of tree and nature study, — of trees as health givers and moral uplifters,
Walnut,
—, black,
Wasteful lumbering,
Weeping willow tree,
Western catalpa,
Whale-oil soap,
White ash,
— birch, European,
— cedar,
— elm,
— flowering dogwood,
Whiteheart hickory,
White maple,
— mulberry,
— oak,
— oak, swamp,
— or gray birch,
— pine,
— pine weevil,
— poplar,
— spruce,
Whitewood,
Willow, weeping,
—, pussy,
Wood, diffuse-porous,
—, diseased, disposal of,
—, early,
— fibers,
—, how to identify specimens,
—, how to judge quality of,
—, late,
— medullary rays,
— parenchyma,
— resin ducts,
—, ring-porous,
— spring,
—, structure, of,
— summer,
Woodland, care of the,
— how to improve by removing trees,
— how to judge, unfavorable conditions,
— trees,
Woodlands, other means of protecting,
Woodlot, small cost of well-selected young trees for
the,
Wood, structure of,
Wooded areas improved by planting new trees,
— areas, preserving soil of,
Woods, identification, properties and uses of common,
—, ring-porous,
— with large and conspicuous rays,
— with pores,
— with resin ducts,
— with small and inconspicuous rays,
— without pores,
— without resin ducts,
Wounds, importance of covering,
—, methods of covering,
—, treating surface,
Xerophytes,
Yellow birch,
— locust,
— oak,
— poplar,
Yew, English,
Yew trees,
Young trees for the woodlot, small cost of well-selected,