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Spikelets linear to narrowly lanceolate or narrowly oblong, often acuminate, usually large, paired or solitary, rarely in threes, pedicelled in open or contracted, rarely spike-like, panicles; rhachilla glabrous, readily disarticulating between the florets and less readily or continuous between the upper glume and lower floret, not or very rarely produced beyond the upper floret. Florets 2, heteromorphous; lower ♂ or rarely barren or reduced to the valve; upper hermaphrodite, smaller than the lower. Glumes persistent, unequal, chartaceous to coriaceous, 3- (rarely 5-) nerved, glabrous, or bristly from black or brown tubercles; lower narrowly lanceolate to broadly ovate or ovate-elliptic, acute, acuminate, obtuse or truncate, rarely setaceously acuminate, one-fourth to three-fourths the length of the spikelet; upper linear-lanceolate to lanceolate, obtuse or truncate, less often acute and rarely setaceously acuminate, as long or nearly as long as the spikelet. Lower floret: valve somewhat similar to the upper glume, glabrous or sparingly hairy, 3- (rarely 5–7-) nerved; valvule linear to linear-lanceolate, shorter than the valve, 2-keeled, membranous. Upper floret linear to linear-lanceolate, terete, with a slender pungent, 2-toothed, emarginate or truncate bearded callus: valve at length thinly coriaceous or coriaceous, pilose, pubescent to glabrescent, 5–9-nerved, shortly 2-lobed, rarely entire, with the lobes obtuse or acute, awned from between the two lobes or from the tip; awn geniculate, twisted below the bend; valvule linear, as long as the valve, 2-keeled, channelled between the keels, with the latter thickened, approximate and tightly embraced by the involute margins of the valve. Lodicules 2, linear or narrowly cuneate. Stamens 2 or rarely 3; anthers linear. Ovary glabrous; styles free, terminal; stigmas plumose, laterally exserted. Grain linear to oblong, terete or with a shallow longitudinal groove, tightly embraced by the valve and valvule; embryo large; hilum linear. —Perennials or rarely annuals; culms mostly erect, slender to robust, simple or rarely branched, 1–5-noded; leaf-blades narrowly linear to linear, flat or convolute, rigid; ligule reduced to a hairy rim; spikelets 2 1/2–18 lin. long, yellowish- to reddish-brown or dark brown.