Spinescent, tipped by or degenerating into a thorn.

Spinose, or Spiniferous, thorny.

Spiral Vessels or ducts, [135].

Spithameous, span-high.

Spora, Greek name for seed, used in compound words.

Sporadic, widely dispersed.

Sporangium, a spore-case in Ferns, &c., [158].

Spore, a body resulting from the fructification of Cryptogamous plants, in them the analogue of a seed.

Spore-case (Sporangium), [158].

Sporocarp, [162].