Aristida Genus three-awn Poaceae

Aristida dichotoma.Anna Gardner.Iowa State (2)

Aristida dichotoma. Anna Gardner.Iowa State (Accessed 5/2014).

Aristida genus grasses (with the exception of A. longifolia) have C4 metabolism (Voznesenskaya et al. 2004; Cerros-Tlatilpa and Columbus 2009) With a few exceptions they are annuals, and often weedy; usually branching from nodes; ligule very small. 

Leaves alternate, narrow, often in-rolled (involute), but sometimes flat.

Flower spikelets with one floret, glumes narrow, membranous, tip pointed to short-awned; lemma hard (indurate), linear tipped by 3 elongate awns, rolled inward around the palea and grain. Awns initially parallel, becoming divergent at maturity or when dry. 

Fruit dry, 1-seeded, lemma remains closely wrapped around the palea and grain, breaking off the inflorescence above the glumes, which remain on the dry plant. 

Habitat; our usually in dry, open sites.