PINNATIFID.  Having the divisions of the frond
              extend halfway or more to the
              rachis or mid vein. 
PINNULE.  A secondary pinna.  In a bipinnate
              frond one of the smaller divisions
              extending to the secondary midvein. 
PROCUMBENT.  Lying on the ground. 
PROTHALLIUM. (Or prothallus.) A delicate, cellular,
              leaf-like structure produced
              from a fern spore, and bearing the
              sexual organs. 
PTERIDOPHYTA.  A group of flowerless plants embracing
              ferns, horsetails, club mosses, etc. 
PUBESCENT.  Covered with fine, soft hairs; downy. 
RACHIS.  The continuation of the stipe
              through the blade or leafy portion
              of the fern. 
REFLEXED. Bent abruptly downward or backward. 
RENIFORM.  Kidney-shaped. 
REVOLUTE.  Rolled backward from the margin or apex. 
ROOTSTOCK. (Or rhizome.) An underground
              stem, from which the fronds are produced. 
SCAPE.  A naked stem rising from the ground. 
SEGMENT.  One of the smaller divisions of a
              pinnatifid frond. 
SERRATE.  Having the margin sharply cut into
              teeth pointing forward. 
SERRULATE.  The same only with smaller teeth. 
SESSILE.  Without a stalk. 
SINUS.  A cleft or rounded curve between two lobes. 
SINUATE.  With strongly wavy margins. 
SORUS A cluster of sporangia; a fruit dot.
(plu.  SORI). 
SPATULATE.  Shaped like a druggist’s spatula or
              a flattened spoon. 
SPIKE.  An elongated cluster of sessile sporangia. 
SPINULOSE.  Spiny; set with small, sharp spines. 
SPORANGE (plu.  A spore case.  A tiny globe in which
  SPORANGIA). the spores are produced. 
STIPE.  The stem of a fern from the ground
              up to the leafy portion; the leaf stalk. 
STOLON.  An underground branch or runner. 
SUBULATE.  Awl-shaped. 
TERNATE.  With three nearly equal divisions. 
TRUNCATE.  Ending abruptly as if cut off. 
TUFT.  Things flexible, closely grouped into
              a bunch or cluster. 
VENATION.  The veining of a frond or leaf. 
VERNATION.  The arrangement of leaves in the bud. 
WHORL.  A circle of leaves around a stem. 
WINGED. Margined by a thin expansion of the rachis.

NOTE

The student should have some idea of the terms genus, species and variety, although they are not capable of exact definition.