Perennial, up to 8 ft. high. Culms erect, terete below, up to 1/2 in. in diam., very glabrous and smooth, 5- or more-noded. Leaf-sheaths terete, firm, striate upwards, more or less hirsute, or quite glabrous and smooth; ligules scarious, truncate, up to 1 1/2 lin. long, ciliate with long hairs from the back; blades linear, very long-tapering to a slender point, slightly contracted at the junction with the sheath, up to 3 ft. long and over 1 in. wide, flat, rigid, glabrous or hirsute towards the base, scabrid above and along the margins, midrib very stout, pale and slightly channelled above, lateral nerves numerous, fine. Racemes fragile, numerous on a common rhachis, usually simple, whorled, up to 6 in. long, straight or flexuous, greenish-yellow or purplish; common rhachis up to more than 10 in. long, very angular, the lowest internode up to 2 in. long, the upper much shorter, smooth below, scabrid upwards, glabrous or bearded at the nodes; joints linear, subclavate and hollow at the tip, 3–3 1/2 lin. long, convex on the back, scaberulous along the angles, disarticulating somewhat obliquely with a narrow cupuliform margin round the scar; pedicels similar to the joints but distinctly shorter, parallel to and somewhat distant from them. Sessile spikelets with an obscure callus and a transverse groove above it, linear-oblong, 2 1/2–3 lin. long. Lower glume chartaceous, subacute or acute, muticous, flat on the back, smooth or aculeolate along the sides, spinulously ciliate on the keels, glabrous, intracarinal nerves 3; upper glume subequal to the lower, chartaceous, boat-shaped, broadly linear in profile, acute, glabrous, scabrid on the keel, 1–3-nerved. Lower floret: valve shorter than the glumes by 1/4, oblong, subacute, with a similar valvule. Upper floret: valve and valvule similar to those of the lower floret, but the former 3-nerved. Anthers 1 1/2 lin. long. Pedicelled spikelet similar to the sessile, but with 2 ♂ florets and with or without a bristle-like awn from the lower glume.
