Culms loosely and extensively rambling, 3–6 1/2 ft. high, repeatedly geniculate, terete or slightly flattened or grooved on one side, slender to moderately stout, branched from most nodes, green or purplish, usually retrorsely scabrid below the nodes and inflorescence, otherwise glabrous and smooth. Leaf-sheaths mostly shorter than the internodes, loose or pushed aside by the branches and exposing the culms, finely striate, ciliate on the margins and at the mouth, densely and retrorsely scabrid especially upwards, terete or more or less compressed and keeled; ligule oblong, obtuse, up to 1 lin. long, glabrous; petiole filiform, from very short in the upper leaves to up to 2 in. long in the lower leaves, finely striate, retrorsely scabrid, loosely to densely pubescent towards and at the apex; blade lanceolate to lanceolate-oblong from a sagittate base with the lobes subobtuse to acute and up to 5 lin. long, tapering upwards to a setaceous tip, 1 1/4–4 1/2 lin. long, 4–10 lin. wide, spreading, thin, sparsely to densely pubescent below, scaberulous, midrib very slender, primary nerves 3–5 on each side of the midrib. Panicle linear-lanceolate in outline, loose, 1 1/2–6 in. long, 1/3–1 1/4 in. wide, terminating in a raceme of 3–7 spikelets; rhachis angular, scaberulous; branches up to 1 1/4 in. long, produced at the apex into a more or less flattened bristle up to 1/3 in. long; peduncle up to 2 1/2 lin. long; burrs compact, 1/4– 3/4 lin. long; branchlets spiny, smooth or slightly scaberulous, up to 2 1/2 lin. long. Spikelets 1 1/2–1 3/4 lin. long, greenish when young, brownish or purplish-brown at maturity. Glumes papillose at the apex; lower truncate, up to 1/3 lin. long; upper very obtuse or slightly acute, up to 3/4 lin. long. Lower floret: valve very densely scabrid. Upper floret: valve minutely verrucose, scaberulous at the tip. Anthers 1 lin. long. Grain 1 lin. long.
