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.
Squamula. A reduced scale, as the hypogynous scales in Grasses.