Plants annual; tufted, without innovations, without glands. Culms (12)25-75 cm, usually erect, sometimes geniculate and branched below, glabrous, reddish. Sheaths glabrous, apices usually with 0.3-2.2 mm hairs; ligules 0.2-0.4 mm, ciliate; blades (5)7-17 cm long, 1-3 mm wide, flat to folded basally, involute apically, abaxial surfaces glabrous, adaxial surfaces scabridulous, sometimes with scattered hairs near the base. Panicles (6)11-21 cm long, 1-13 cm wide, ovate to somewhat contracted, open; primary branches 0.5-12 cm, (12)15-20 per culm, appressed or diverging up to 60° from the rachises, often capillary, naked near the base; pulvini glabrous; pedicels 0.3-5 mm, mostly appressed. Spikelets 2-4.6 mm long, 0.9-2 mm wide, narrowly ovate, greenish-yellow to plumbeous and with a reddish-purple tinge, with 5-15 florets; disarticulation acropetal, paleas persistent. Glumes lanceolate to ovate, membranous; lower glumes 0.4-0.9 mm; upper glumes 1-1.3 mm, occasionally 3-veined; lemmas 1-1.3 mm, broadly ovate, membranous, often reddish-purple, lateral veins conspicuous, often greenish, apices acute; paleas 0.9-1.1 mm, hyaline, keels scabridulous, apices obtuse; anthers 2, 0.1-0.2 mm, reddish-purple. Caryopses 0.3-0.5 mm, subglobose to obovoid, not grooved, translucent, faintly striate, reddish-brown. 2n = 80.

Eragrostis gangetica is an Asian species that now grows in the southeastern United States. It can be found in the sandy margins of ponds, roadsides, and ditches, at 0-100 m, usually in association with Pinus, Taxodium distichum, Rynchospora, and Steinchisma hians. Eragrostis gangetica is similar to E. bahiensis, but differs from that species in its annual habit and shorter spikelets, lemmas, anthers, and caryopses.