_Runcinate._ Sharply incised, with the segments directed backward.

_Runner._ A filiform or very slender stolon.

_Saccate._ Sac-shaped.

_Sagittate._ Shaped like an arrow-head, the basal lobes directed downward.

_Salver-shaped_ (corolla). Having a slender tube abruptly expanded into a flat limb.

_Samara._ An indehiscent winged fruit.

_Scabrous._ Rough to the touch.

_Scalariform_ (vessels). Having transverse markings like the rounds of a ladder.

_Scape._ A peduncle rising from the ground, naked or without proper foliage.

_Scapose._ Bearing or resembling a scape.

_Scarious._ Thin, dry, and membranaceous, not green.

_Scorpioid_ (inflorescence). Circinately coiled while in bud.

_Scurf._ Small bran-like scales on the epidermis.

_Scymitar-shaped_ (leaf). Curved with a flat-triangular section, the straighter edge the thickest.

_Seed._ The ripened ovule, consisting of the embryo and its proper coats.

_Segment._ One of the parts of a leaf or other like organ that is cleft or divided.

_Sepal._ A division of a calyx.

_Septicidal_ (capsule). Dehiscing through the part.i.tions and between the cells.

_Septum._ Any kind of part.i.tion.

_Serrate._ Having teeth pointing forward.

_Serrulate._ Finely serrate.

_Sessile._ Without footstalk of any kind.

_Setaceous._ Bristle-like.

_Setose._ Beset with bristles.

_Setulose._ Having minute bristles.

_Sheath._ A tubular envelope, as the lower part of the leaf in Gra.s.ses.

_Sheathing._ Enclosing as by a sheath.

_Shrub._ A woody perennial, smaller than a tree.

_Silicle._ A short silique.

_Silique._ The peculiar pod of Cruciferae.

_Silky._ Covered with close-pressed soft and straight p.u.b.escence.

_Simple._ Of one piece; not compound.

_Sinuate._ With the outline of the margin strongly wavy.

_Sinus._ The cleft or recess between two lobes.

_Smooth._ Without roughness or p.u.b.escence.

_Sorus_ (pl. _Sori_). A heap or cl.u.s.ter, applied to the fruit-dots of Ferns.

_Spadix._ A spike with a fleshy axis.

_Spathe._ A large bract or pair of bracts enclosing an inflorescence.

_Spatulate._ Gradually narrowed downward from a rounded summit.

_Spicate._ Arranged in or resembling a spike.

_Spiciform._ Spike-like.

_Spike._ A form of simple inflorescence with the flowers sessile or nearly so upon a more or less elongated common axis.

_Spikelet._ A small or secondary spike.

_Spindle-shaped._ Same as Fusiform.

_Spine._ A sharp woody or rigid outgrowth from the stem.

_Spinose._ Spine-like, or having spines.

_Sporangium._ A spore-case.

_Spore._ The reproductive organ in Cryptogams which corresponds to a seed.

_Sporocarp._ The fruit-cases of certain Cryptogams containing sporangia or spores.

_Spur._ A hollow sac-like or tubular extension of some part of a blossom, usually nectariferous.