Perennial, compactly cæspitose, with intravaginal innovations and a short præmorse rhizome. Culms erect, rather firm, coated at the base with the fibrous remains of the old sheaths, simple, 2–4 ft. high, glabrous or sparingly hairy below the inflorescence, 1–3-noded, the uppermost internode by far the longest. Leaves mostly crowded near the base; lowest sheaths rather firm, strongly striate, appressedly hairy to densely silky-tomentose at the base, persistent, at length breaking up into fibres, the following usually glabrous except at the nodes which are either densely bearded or more rarely finely pubescent or very rarely quite glabrous, uppermost very long, rather loose; ligules short or sometimes up to 1 1/2 lin. long, scarious, obtuse or truncate, glabrous; blades linear, tapering to a fine point, up to 9 in. (rarely more) by 1 1/2–2 1/2 lin., flat or with involute margins, firm, glabrous, flexuous, green, slightly rough above and on the margins, midrib slender, primary lateral nerves 3–4 on each side, prominent above. Racemes usually very numerous, gathered into an oblong-panicle 5–7 (rarely 9) in. long, simple or the lowest compound, solitary or fascicled on a scabrid or hirsute angular common axis of variable length (mostly exceeding the lower racemes), sessile or the lower bare at the base with traces of arrested spikelets, slender, straight or flexuous, erect or more or less spreading, 2–5 in. long, dense or more or less loose; rhachis very slender, sometimes wavy, triquetrous, 1/7– 1/5 lin. wide, lateral angles scabrid or setosely ciliate, internodes up to 1 1/2 lin. long; pedicels in fascicles of 3–6, unequal, the longest up to 1 1/2 lin. long, angular, scabrid and more or less copiously setose upwards, the uppermost setæ usually equalling the spikelets. Spikelets oblong to ovate-oblong, subacute, 7/10– 8/10 (rarely 9/10) lin. long, greyish- or brownish-green on the flat, chestnut-to black-brown on the convex side, quite glabrous. Lower glume suppressed, very rarely represented by a minute hyaline truncate scale; upper a tightly appressed delicate hyaline scale, rotundate-ovate, very obtuse, nerveless or faintly 1-nerved, 2/10– 3/10 lin. long. Lower floret oblong, as long as the spikelet or slightly shorter, tightly appressed to the face of the upper floret, hyaline, 3-nerved, quite glabrous; valvule a very delicate narrow scale up to 1/6 lin. long; lodicules very minute. Upper floret corresponding in outline and size to the spikelet, chestnut-brown or at length almost black, somewhat shining, chartaceous, very tough; valve with distant margins. Anthers up to 1/2 lin. long.
