Digitaria cognata is a perennial C3 grass (Waller and Lewis 1979) un, 40-70 cm, tufted, stems much branched at base; lower sheaths hairy.
Leaves alternate. 5-10 cm long, 0.2-0.6 cm wide, flat.
Flower spikelets solitary at branch tips, 1-flowered, about 0.3 cm long, glumes hairy between veins; flowering branches elongate 3-angled, rough-textured, 1-4 cm long; June-Oct., inflorescence open, diffuse, purplish; a third to a half the height of plant, axils hairy, breaking off at maturity and acting as a tumble-weed to disperse seeds.
Wetland status: NL.
Frequency in NYC: Very infrequent.
Origin: Mostly S.E. and Midwestern U.S. Occasionally N.E. to NH
Habitat: Dry, open, sandy soil.