Plants perennial; cespitose, with innovations, without rhizomes, not glandular. Culms 30-75 cm, erect, glabrous below. Sheaths mostly glabrous, hairy at the apices, hairs to 4 mm; ligules 0.2-0.3 mm; blades 10-25(40) cm long, 1-5 mm wide, involute, glabrous abaxially, scabridulous adaxially, sometimes also sparsely pilose. Panicles (3)5-30 cm long, 1-15 cm wide, from narrowly oblong, glomerate, and interrupted below to ovate and open; primary branches 0.5-12(16) cm, appressed or diverging up to 40° from the rachises, stiff; pulvini glabrous or sparsely hairy; pedicels 0-1(3) mm, appressed, flattened. Spikelets 6-16(23) cm long, 2.4-5 mm wide, ovate to linear-elliptic, flattened, stramineous, with reddish-purple margins or completely reddish-purple, with 10-45 florets; disarticulation basipetal, florets falling intact and before the glumes. Glumes ovate-lanceolate to lanceolate, membranous; lower glumes 1.7-3 mm; upper glumes 2.2-4 mm, apices acuminate; lemmas 2-6 mm, ovate, membranous to leathery, apices usually acuminate or attenuate, sometimes acute; paleas 1.5-3 mm, membranous to leathery, narrower than the lemmas, apices obtuse, sometimes bifid; anthers 2, 0.2-0.5 mm, brownish. Caryopses 0.8-1.3 mm, ellipsoid, somewhat laterally flattened, smooth, reddish-brown. 2n = 40.

There are two subspecies of E. secundiflora; plants from the Flora region belong to E. secundiflora subsp. oxylepis (Torr.) S.D. Koch. They grow in sandy soils, dunes, grasslands, beaches, and roadsides of the southern United States and northern Mexico, at 0-1000 m. Eragrostis secundiflora J. Presl subsp. secundiflora grows in Mexico and Central and South America.