Plants cespitose, cylindrical to ovate above. Culms 30-100(140) cm; internodes usually glaucous; branches mostly erect, straight.Sheaths smooth; ligules 0.3-1.5 mm, sometimes ciliate, cilia to 0.7 mm; blades 6-48 cm long, 0.8-5 mm wide, glabrous or densely pubescent with spreading hairs. Inflorescence units 2-31 per culm; subtending sheaths (2.6)4.1-4.5(13.5) cm long, (1.5)2.7-4.7(8) mm wide; peduncles (1)5-31(195) mm, with 2-5 rames; rames (1.5)2.8-4.2(6) cm, exserted or not at maturity, pubescence increasing in density distally within each internode. Sessile spikelets (3)3.9-4.7(5.7) mm; callus hairs 1-5 mm; keels of lower glumes scabrous only beyond midlength; awns 8-24 mm; anthers 1, 0.6-1.4(1.7) mm, yellow or purple. Pedicellate spikelets vestigial or absent. 2n = 20.
Andropogon gyrans extends from the southeastern United States to the Caribbean and Central America.