aving 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.

A _species_, or kind, is in botany the unit of classification. It embraces
all such individuals as may have originated in a common stock. Such
individuals bear an essential resemblance to each other, as well as to
their common parent in all their parts. E.g., the Cinnamon fern is a kind
or species of fern with the fronds evidently of one kind, and of a common
origin, and all producing individuals of their own kind by their spores or
rootstocks. When such individuals differ perceptibly from the type in the
shape of the pinnae, or the cutting of the fronds, we have _varieties_ as
_frondosum_, _incisum_, etc. Or if the difference is less striking the
word _form_ is used instead of variety, but in any given case opinions may
differ in respect to the more fitting term.

A _genus_ is an assemblage of species closely related to each other, and
having more points of resemblance than of difference; e.g., the royal fern,
the cinnamon fern, and the interrupted fern are alike in having similar
spore cases borne in a somewhat similar manner on the fronds, and forming
the genus _Osmunda_. In like manner certain members of the clover
group--re