Perennial. Culms erect or geniculately ascending from small tough nodulose rootstocks, sometimes prostrate and rooting at the nodes, up to 1–3 ft. high, very slender, weak, compressed, branched in the lower part or simple, glabrous and smooth, the ascending portion 2–6-noded, the uppermost internode (peduncle) up to 6 in. long. Leaf-sheaths thin, glabrous and smooth or with a few short hairs towards the blade, the lower and intermediate more or less loose and exposing the culm, keeled upwards, the upper tight; ligule reduced to a ciliate rim; blade linear from a narrow or slightly contracted base, long and finely acute, 2–6 in. long, 1 1/2–2 lin. wide, flat, thin, usually appressedly pubescent, sometimes from minute tubercles, rarely quite glabrous, smooth except for the minutely scaberulous margins or asperulous above, midrib differentiated only below. Inflorescence a very narrow sparsely spiculate and interrupted spike-like panicle, straight or more often flexuous, 2–8 in. long by about 3 lin. wide, glabrous; axis filiform, finely striate or grooved, minutely scaberulous; branches erect, frequently terminating in a bristle, the lower usually distant by about 1/2 in. and up to 1/2 in. long and bearing up to 12 mostly perfect spikelets, becoming shorter upwards and merging into subsessile clusters or solitary spikelets; bristles slender, flexuous, obscure, minutely scaberulous, up to 1 1/2 lin. long; pedicels up to 3/4 lin. long, with minutely discoid tips. Spikelets lanceolate- or ovate-oblong to oblong in back view, obtuse or acute (when young), obliquely lanceolate to oblong and slightly gaping in profile, 1 1/4–1 1/2 lin. long and 1/2 lin. wide across the back, pale greenish. Glumes very thinly membranous, loose; lower broadly ovate to rotundate, obtuse, one-fourth to one-third the length of the spikelet, finely 3-nerved; upper broadly elliptic-oblong, obtuse, one-third to half the length of the spikelet, finely 3- to sub-5-nerved. Lower floret ♂; valve 5–7-nerved; valvule lanceolate- to ovate-oblong, obtuse; anthers 3/4 lin. long. Upper floret as long as or slightly shorter than the lower, lanceolate and acute in back view, oblique in profile, 1–1 1/4 lin. long: valve and valvule at first thinly chartaceous, at length thinly crustaceous, finely granular-punctate and delicately transversely rugose; anthers 1/2 lin. long. Grain 3/4 lin. long.