A loosely tufted annual. Culms erect or geniculately ascending and rooting at the lower nodes, very slender to slender, 1–3 1/2 ft. high, terete or slightly compressed below, branched from the lower and intermediate nodes, up to 6- or rarely many-noded, smooth, glabrous except for the pubescent nodes or sometimes also hairy below them, lower internodes up to 2 in. long, intermediate up to 4 in. long, the uppermost internode (peduncle) up to 5 in. long. Leaf-sheaths narrow, finely striate, compressed and keeled, glabrous or pubescent, ciliate on the margins, the lower shorter than the internodes and soon exposing them; ligule reduced to a dense fringe of hairs up to 3/4 lin. long; blade lanceolate, in the lower leaves usually from a much attenuated or petioled base, in the upper from a narrowed base, tapering to a fine point, 1 1/2–10 in. long and up to 1 in. wide, at first pleated, eventually flat, thin and flaccid or rather firm, green, glabrous or more often sparsely hairy with white hairs from minute tubercles on the nerves, rough, midrib very slender, primary lateral nerves very fine, 4–6 on each side. Inflorescence a loose flexuous panicle, linear, lanceolate or oblong in outline, up to 6 in. long and 1 1/2 in. wide; axis very slender, angular, finely scaberulous, beset with white spreading hairs or glabrous; branches spreading to suberect, solitary, distant, the lower by 1 1/4– 1/2 in., very slender, triquetrous, scaberulous, hairy like the axis or glabrous, bearing up to 30 mostly contiguous subsessile spikelets in simple secund racemes, rarely branched below and bearing short secondary racemes, terminating in a bristle and with most of the spikelets subtended by one; bristles fine, flexuous, rough, up to 3–6 1/2 lin. long; pedicels reduced to minute stumps. Spikelets elliptic-oblong to oblong, obtuse or shortly acute in back view, semi-elliptic-oblong in profile, 1 1/4–1 1/2 lin. long, 1/2– 2/3 lin. wide in back view, greenish, rarely purplish. Lower glume rotundate, obtuse, one-fourth to one-third the length of the spikelet, finely 3-nerved, subhyaline; upper as long or almost as long as the upper floret, elliptic-oblong, obtuse, thinly membranous, 5–7-nerved. Lower floret barren or with rudimentary anthers: valve corresponding in outline to the spikelet as seen from the back, flat or depressed, 5-nerved; valvule linear, one-half to three-fourths the length of the valve, keels narrowly winged. Upper floret hermaphrodite, elliptic-oblong to oblong, acute in back view, semi-elliptic-oblong in profile: valve and valvule crustaceous, finely transversely rugose.
