Plants perennial; cespitose. Culms 20-100 cm. Sheaths compressed, glabrous, margins villous distally; ligules 1-2.5 mm, ciliate; blades 8-25 cm long, 2-5 mm wide, flat or folded, scabrous on both surfaces. Panicles 6-15 cm, tightly spikelike, pale green; rachisesscabrous or villous; bristles usually solitary, 4-15 mm, ascending. Spikelets 2.2-2.8(3) mm, elliptical. Lower glumes about 1/2 as long as the spikelets, 3-veined; upper glumes from 3/4 as long as to equaling the florets, 5-veined; lower lemmas equaling the upper lemmas, 5-veined; lower paleas 1/2-3/4 as long as the upper paleas, lanceolate; upper lemmas apiculate, finely and transversely rugose; upper paleas similar. 2n = 54, 68, 72.
Setaria leucopila grows in the southwestern United States and northern Mexico. It is the most common of the perennial Plains bristlegrasses.