Perennial, up to 2 1/2 ft. high, with intravaginal innovations. Culms erect from a short rhizome, densely coated at the base with the firm persistent basal leaf-sheaths, very slender, simple, 3–4-noded, more or less compressed downwards, glabrous and smooth except close to the inflorescence where it is slightly rough and prominently striate, lowest internode short, the uppermost (peduncle) up to 1 ft. long. Leaf-sheaths firm, closely striate, intermediate and upper shorter than the internodes, keeled, glabrous, usually slightly rough; ligule very short, ciliolate; blade linear from a base as wide as the sheath, tapering to a long fine setaceous point, firm, slightly flexuous, up to 8 in. long and 2 lin. wide, flat or folded, glaucous, glabrous except for a few hairs behind the ligule, scaberulous, midrib fine, sharply prominent below, primary lateral nerves about 3 on each side. Inflorescence a straight somewhat loose continuous cylindric false spike, 1–1 1/2 (rarely to 4) in. long, 3–3 1/2 lin. wide (exclusive of the bristles), pale straw-coloured or pale purplish; axis coarsely striate, minutely tomentellous; branches reduced to sessile involucres each supporting 1 or 2 spikelets (if 2 then only one perfect); bristles fine, 4–10 to each involucre, pale with purplish tips, the longer up to 3 1/2 lin. long; pedicels reduced to short stumps with discoid tips. Spikelets elliptic-oblong and acutely acuminate in back view, broadly semi-ovate in profile, 1 3/4–2 in. long by 1 lin. wide (in profile), glabrous, pallid or pale purplish. Glumes membranous; lower rotundate-ovate, subacute and mucronate, slightly more than half the length of the spikelet, 3–5-nerved; upper broadly elliptic-oblong, subacute and mucronate, about three-quarters the length of the spikelet, 5- (rarely 7-) nerved. Lower floret ♂: valve as long as the spikelet and corresponding to it in outline as seen in front view, depressed or flat on the back, 5-nerved; valvule almost as long as the valve, keels narrowly marginate. Upper floret hermaphrodite, elliptic-oblong, acute and mucronate in back view, obliquely lanceolate-oblong in profile: valve pale throughout or with a pale purplish tip, very finely transversely rugose; valvule delicately punctate.
