Plants perennial; cespitose, not rhizomatous. Culms 90-250 cm, stout. Sheaths rounded below, shiny, glabrous, rarely sparsely hairy apically, hairs to 6 mm; ligules 1-2 mm; blades 20-70 cm long, 3-10 mm wide, flat (rarely involute), glabrous abaxially, scabrous adaxially, margins scabrous; flag blades ascending. Panicles 20-60 cm long, 12-26 cm wide, open, broadly lanceolate, exserted; primary branches 1.5-10 cm, spreading 20-70° from the rachis; secondary branches appressed, spikelet-bearing to the base; pulvini glabrous; pedicels 0.2-0.5 mm, mostly appressed. Spikelets 1.5-2.5 mm, crowded, purplish or greenish. Glumes unequal, lanceolate to ovate, membranous; lower glumes 0.5-1 mm, often appearing veinless; upper glumes 0.8-2 mm, 2/3 or more as long as the florets; lemmas 1.2-2.5 mm, ovate, membranous, glabrous, acute to obtuse; paleas 1.1-2.5 mm, ovate, membranous, glabrous; anthers 1.1-1.3 mm, yellowish to purplish. Fruits 1-1.4 mm, ellipsoid, reddish-brown or blackish, striate. 2n = 36.
Okla., N.Mex., Tex., Utah, Calif., S.C., Ariz.
Sporobolus wrightii grows in moist clay flats and on rocky slopes near saline habitats, at elevations of 5-1800 m. Its range extends to central Mexico.