n. [ NL.; L. spina spine + facere to make. ] 1. (Bot.) A genus of chiefly Australian grasses, the seeds of which bear an elastic spine. Spinifex hirsutus (black grass) and Spinifex longifolius are useful as sand binders. Spinifex paradoxusis a valuable perennial fodder plant. Also, a plant of this genus. [ Webster 1913 Suppl. ]

2. Any of several Australian grasses of the genus Tricuspis, which often form dense, almost impassable growth, their leaves being stiff and sharp-pointed. [ Webster 1913 Suppl. ]