Aristida palustris (Chapm.) Vasey

Longleaf Threeawn

Natural range:  Southeastern U.S.

Habitat:  Moist sites, swamps, shores, seasonal ponds, wet pinewoods

Florida status:  Native, common, widespread

Recognition:  Inflorescence a panicle. Lower glume conspicuously 2-keeled (the only other sometimes 2-keeled species is A. purpurascens).  Awns subequal (lateral awns > 1/2 the length of the central awn), usually 15-40 mm long.

Aristida patula has the lateral awns < 1/2 the length of the central awn.

Aristida purpurascens has the lower glume < 9 mm long (vs. 9 mm or longer),  a longer ligule (0.2 vs. 0.1 mm), and the central awn 8-25 (vs. 15-40) mm, with the lateral awns subequal to it.  Aristida purpurascens differs further by tending toward curled (vs. not curled) leaf blades.