Plants cespitose. Culms 70-150 cm. Sheaths smooth or scabrous, sometimes pilose; ligules 0.4-1.5 mm, ciliate; blades 1-3 mm wide, pubescent or glabrous and glaucous. Inflorescence units 2-30+ per culm; peduncles usually 5-20 mm, with (1)2 rames; rames 3-4 cm, exserted at maturity, terminating in a sessile-pedicellate spikelet pair; internodes sparsely to densely villous, hairs from as long as to twice as long as the sessile spikelets. Sessile spikelets 4.5-8.4 mm; callus hairs to 8 mm; awns 10-25 mm; anthers 3, 1.2-2.3 mm. Pedicellate spikelets 1.5-3.6 mm, sterile. 2n = 40, 60.
Andropogon ternarius grows in the southeastern United States and northern Mexico. It is planted as an ornamental and for erosion control on slopes in poor and sandy soils, and is tolerant of coastal conditions.