Perennial, up to 8 ft. high, in smaller or larger tufts, from a very short and abundantly rooting rhizome with extra- and intra-vaginal innovations, covered with whitish cataphylls, the lowest of them tomentose. Culms erect or geniculate at the base, often more or less compressed below, terete upwards, glabrous, smooth, up to over 4 lin. thick, about 5-noded, sparingly branched, sheathed all along or the upper at length more or less exserted. Leaf-sheaths rather tight, the lower whitish, more or less compressed and keeled upwards, the upper firmly subherbaceous, terete, all smooth, glabrous and loosely striate; ligules marked by a usually delicately pubescent zone along the junction of blade and sheath, rarely with a few short stiff hairs; blades linear from a slightly rounded and constricted or equally wide base, tapering to a very long and slender point, 1/2 to over 1 ft. long, 2 1/2 to over 5 lin. wide, flat, somewhat firm, but flexuous, glabrous, more or less rough upwards and along the margins, otherwise usually smooth, midrib very slender, whitish upwards. Panicle erect, linear to linear-oblong, 4–9 in. by 1–2 in., usually rather dense; axis somewhat slender, angular and more or less grooved below, triquetrous upwards, or triquetrous all along, scabrid along the angles at least upwards and usually with few to numerous stiff hairs or bristles from the nodes; branches numerous, very much longer than the internodes, the lower and intermediate often fascicled or 2-nate, 2/3–1 1/2 in. long, forming suberect or more or less spreading straight or curved or flexuous secund very dense sessile simple false spikes; rhachis slender, triquetrous, from less than 1/4 to almost 1/2 lin. wide, scaberulous along the angles, more or less finely pubescent and here and there with a long hair; pedicels mostly 2-nate, almost reduced to the small discoid tips, the pairs less than 1/4 lin. distant. Spikelets 3–4-ranked, ovate in outline, cuspidate to caudate-acuminate or those of the outer ranks (rarely most or all) awned, 1–1 1/2 lin. long (excluding the awn), pale or tinged with purple or brown. Glumes thinly membranous, finely and upwards somewhat prominently nerved, nerves scabrid to hispidulous; lower broadly ovate from a clasping base, apiculate or mucronulate, 3–5-nerved, minutely rigidly pubescent or almost glabrous between the nerves, ciliolate along the margin; upper glume ovate, cuspidate-acuminate, very concave, as long as the spikelet (excluding the awn, if any), 5-nerved, more or less pubescent or scaberulous between the nerves at least upwards. Lower floret ♂: valve similar to the upper glume but flat on the back and frequently passing into a fine rigid scabrid awn, 3–4 (rarely 6) lin. long, 5- or upwards 7-nerved; valvule almost as long as the valve, broad-oblong, keels rough upwards; anthers 2/3 lin. long. Upper floret hermaphrodite, ovate to elliptic-ovate in outline, turgid, apiculate, almost as long as the spikelet, greenish or greyish-white, polished; valve and valvule crustaceous; anthers 1 lin. long.
