Tall, openly caespitose sometimes ± rhizomatous naturally occurring hybrid. Leaf-sheath glabrous. Branching intravaginal and extravaginal. Ligule 1-1.5 mm. Auricles stiff, 1 or 2, clasping, hairs few or glabrous. Leaf-blade c. 30 cm × 4 mm, multiribbed, midrib conspicuous, adaxially finely prickle-toothed, abaxially shining and smooth, margins prickle-toothed. Culm 50-70 cm, ribbed, nodes and internodes glabrous. Panicle 12-20-(30) cm, strict of 10-20 nodes, branches binate, the longer with up to 5 spikelets or more the shorter with 1 spikelet though sometimes > 1, uppermost 5-8 with solitary spikelets; rachis and branches prickle-toothed on margins. Spikelets 10-20 mm of 4-8 florets. Glumes unequal; lower 4-6 mm, 3-nerved, upper 5-8 mm, 5-nerved of which 1-3 are usually prominent. Lemma 6-8.5 mm, 5-nerved, rounded, small prickle-teeth scattered throughout, denser laterally below and on membranous margins; apex with hyaline lobes, awnless or awn to 3 mm. Palea 6-7.5 mm, apex bifid, ciliate, keels finely toothed almost to base, interkeel hairs few at apex. Callus 0.25 mm, glabrous. Rachilla 1-1.5 mm, short finely stiff hairy. Lodicules 1-2 mm, deeply lobed, sometimes twice-lobed; glabrous. Anthers 2.5-3 mm, caudate, sometimes malformed. Gynoecium: ovary c. 1 mm, apex glabrous; stigma-styles c. 2 mm.