Perennial, up to over 3 ft. high. Culms slender, at least 3–4-noded, terete, glabrous, smooth. Leaf-sheaths terete, glabrous or more or less hirsute upwards, glaucous, produced at the mouth into lanceolate acute auricles up to over 6 lin. long; ligules scarious, as long as and adnate to the auricles of the sheath; blades linear, long and narrowly attenuated towards the base and there generally much longer than the sheath, long-tapering to a fine point, up to over 1 ft. long and 2 lin. wide, firm, rigid, glabrous or loosely hairy, particularly below, rough all over or smooth on the upper surface towards the base, midrib whitish, rather stout and prominent downwards, primary lateral nerves 2–3, raised above, obscure below. Inflorescence a very scanty spatheate panicle, up to 2 1/2 ft. long, of up to 4 very distant 2-rayed tiers, or the lowest branch undivided at the base; spathes like the preceding leaves, the lower with well developed blades; rays often very unequal, the primary often up to over 1 ft. long, filiform, erect, strict. Spatheoles linear-lanceolate, 3–4 in. long, passing into a short to very short subulate or setaceous rudimentary blade, subherbaceous to scarious, greenish or very slightly tinged with red or brown, glabrous, at length more or less tightly inrolled; peduncle terminally shortly exserted. Racemes 2-nate, one sessile, the other with a very short base, slender, flexuous, up to 3 in. long, tinged with purple or violet, conspicuously dorsi-ventral, one side exhibiting the grooved sessile spikelets with the joints and the pedicelled spikelets in profile and the other the backs of the pedicelled spikelets and between them the broad backs of the upper glumes; joints and pedicels broad-linear to cuneate-linear, 1 1/2 lin. long, shortly ciliate, glossy, tips obliquely truncate, obscurely concave. Sessile spikelets heterogamous or of the lowest pair of the sessile raceme homogamous or imperfect, wedged in between the joint and pedicel, laterally much compressed, linear in front view, 2 1/2 lin. long, glabrous, yellowish, reddish or brownish at the tips; callus short, very shortly bearded. Glumes equal, the lower subcoriaceous, minutely truncate, with a deep and narrow groove between the keels which are smooth up to two-thirds and then spinulously ciliate, one nerve on each side of the groove, 2–3 in or close to the keels; upper glume boat-shaped with a broad rounded back below and a scaberulous keel upwards, 3-nerved, margins narrow, hyaline, ciliolate. Lower floret reduced to an oblong 2-nerved hyaline ciliolate valve, slightly shorter than the glumes. Upper floret hermaphrodite: valve broad-oblong, 2-lobed, 1 3/4 lin. long, ciliate; awn fine, kneed at about the middle, column and bristle each about 5–6 lin. long; valvule oblong, 2-nerved, over 1 lin. long, eciliate. Anthers 1 3/4 lin. long. Pedicelled spikelets lanceolate, acute, reddish, 2 1/2–3 lin. long; lower glume mucronate, about 13-nerved, keels spinulously ciliolate, upper mucronate, 3–5-nerved, ciliolate; valves of both florets oblong, hyaline, the lower 2-, the upper 3-nerved, 2 1/2 lin. long; valvule as in the sessile flower but nerveless.