Annual, up to 4 ft. high. Culms erect or geniculately ascending, frequently with stilt roots from the lower nodes, terete, slender to stout, firm, many-noded with the nodes pilose, simple or sparingly branched, smooth and glabrous or sparsely hairy and tubercled. Leaf-sheaths from half as long to as long as the internodes, tight or loose, eventually exposing the frequently purplish culm, finely striate, sparsely pilose, densely and finely tubercled; ligule reduced to a short ciliate rim; blade linear to linear-lanceolate, narrowed or rounded at the base, long and finely acute, 2 1/2–8 in. long, 3–7 lin. wide, flat, finely nerved, sparsely hairy above, hairy and tubercled below on the nerves. Panicle narrowly oblong to broadly ovate, effuse or contracted and dense, 3–8 in. long, 1/2–3 in. wide, pale green to purple, with greenish or purple awns, exserted or more often sheathed at the base; rhachis finely striate, terete, slender, smooth or minutely puberulous; branches erect or spreading, 2–3-nate, finely and much divided from the base and at intervals upwards; branchlets and pedicels capillary, flexuous, purplish, minutely scaberulous, the latter 1/4–1 lin. long, with paler thickened tips. Spikelets linear- to ovate-oblong, 3/4–1 lin. long, glabrous or sparsely to densely pilose with short soft appressed white hairs, pale green, tinged with purple upwards, finely nerved. Lower glume reduced to a minute, hyaline annular rim; upper broadly elliptic-oblong when flattened, as long as the spikelet, 2-lobed with the lobes denticulate or entire (rarely), delicately membranous, glabrous or pilose, 7-nerved. Lower floret barren: valve narrowly oblong when flattened, equal to or slightly shorter than the upper glume, similar in hairiness and texture, 2-lobed with the lobes finely acute and about one-third the length of the valve, with a fine flexuous awn 5–10 lin. long from the sinus, 3- or rarely obscurely 5-nerved; valvule 0. Upper floret hermaphrodite: valve ovate-oblong, about 2/3 lin. long, minutely 2-fid, obscurely 3-nerved, hyaline; valvule slightly longer and broader; anthers 1/2– 2/3 lin. long.
