Plants perennial, forming loose clumps, usually with fewer than 30 culms per clump, sometimes weakly rhizomatous. Culms 30-140 cm tall, erect to slightly decumbent; nodes 4-7, most exposed, usually glabrous, sometimes puberulent. Leaves evenly distributed; sheaths often purplish, scabrous or smooth, glabrous or, particularly those of the lower leaves, retorsely puberulent to hairy; auricles usually present on the lower leaves, up to 2.5 mm long, often purplish; ligules up to 1 mm long, truncate, erose-ciliolate or entire; blades 2-13(17) mm wide, usually lax, sometimes loosely involute, adaxial (upper) surface glabrous, pilose, or vilolous, sometimes strigose over the veins. Inflorescence spicate, 5-21 cm long, (0.2)0.5-2 cm wide, erect to slightly nodding, usually with 2 spikelets per node, sometimes with 1 at all or almost all nodes, occasionally with 3 at some nodes; internodes 4-8(12) mm long, 0.15-0.5 mm thick at the thinnest portion, angles scabrous, surfaces glabrous, below the spikelets. Spikelets 8-25 mm long, usually green, sometimes purplish at high latitudes and elevations, appressed to slightly divergent, lowest floret fully functional; disarticulation above the glumes, beneath each floret. Glumes subequal, glabrous and smooth throughout or scabrous over the veins, 3/4 as long as or equalling the adjacent lemma, bases often overlapping, usally flat and thin, with evident venation, glume body (6)9-14(19) mm long, 0.6-1.5(2) mm wide, linear-lanceolate, widening above the base, entire, (1)3-5(7)-veined, 2-3 veins extending to the glume tip, margins 0.1-0.2 mm wide, whitish to hyaline, tapering towards the tip; glumes tips unawned or awned, awns to 5(9) mm long, straight; lemmas (8)9-14(16) mm long, glabrous, scabrous, or shortly hairy; lemma tips usually awned, 1-30(35) mm long, usually straight to flexuous, sometimes slightly curving; paleas 7-13 mm long, keeks straight to slightly concave, usually scabrous, sometimes shortly ciliate, tips narrow, often bidentate; anthers 1.5-3.5 mm long. Flowering May to July.
