GROUP VI.  TREES TOLD BY THEIR FORM:  ELM, POPLAR, GINGKO AND WILLOW

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.

AMERICAN ELM (Ulmus americana)

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.