\Spin"i*fex\, n. [NL.; L. spina spine + facere to
make.]
1. (Bot.) A genus of chiefly Australian grasses, the seeds of
   which bear an elastic spine. {S. hirsutus} (black grass)
   and {S. longifolius} are useful as sand binders. {S.
   paradoxus}is a valuable perennial fodder plant. Also, a
   plant of this genus.
2. Any of several Australian grasses of the genus
   {Tricuspis}, which often form dense, almost impassable
   growth, their leaves being stiff and sharp-pointed.