Perennial, yellowish green or glaucous tufts, (3)— 10— 65 cm, with culms often much overtopping leaves; branching intravaginal. Leaf-sheaths smooth, subcoriaceous, greyish to straw-coloured; ligule 0.5— 1.5—(2) mm, tip truncate to rounded, or shortly tapered; leaf-blades (3)—5—12 cm × (1.5)—2—3.5 mm, flat or folded, abaxially smooth, adaxially shallowly ridged and scaberulous on ridges, margins scaberulous, tip hooded. Culms 15-40 cm, smooth, erect or spreading. Panicle (1.5)—4—15 × 0.4—5-{7) cm, lanceolate, or narrow-oblong to ovate, usually contracted, sometimes more open; branches scabrous, all, or at least the shortest, bearing densely clustered spikelets to the base. Spikelets 3.5—5.5 mm, (3)—4— 5-{8)-flowered, greyish green, often purple tinged. Glumes ± unequal, elliptic to ovate, obtuse to subacute, midnerve often finely scabrous above, tips minutely ciliate; lower glume 0.7-1.5—(1.8) mm, 1- nerved; upper glume 1.2—2 mm, 3-nerved. Lemma 1.7-2.6 mm, 5-nerved, with short hairs at base and on lateral nerves for a short distance near base or sometimes on lower half, elliptic-oblong, minutely ciliate across subobtuse tip, midnerve reaching tip of lemma and often minutely excurrent, minutely scabrous near tip. Palea ± = lemma, tip shallowly bifid, keels ciliate-scabrous in upper ½-2/3. Rachilla 0.4-0.8 mm. Anthers 0.5-0.9 mm. Caryopsis 1.2— 1.5 × 0.4-0.6 mm. 2n = 28. Naturalised from N. America and Europe.

Perennial, yellowish green or glaucous tufts, (3)-10-65 cm, with culms often much overtopping leaves; branching intravaginal. Leaf-sheath glabrous, subcoriaceous, greyish to straw-coloured. Ligule 0.5-1.5-(2) mm, truncate to rounded, or shortly tapered. Leaf-blade (3)-5-12 cm × (1.5)-2-3.5 mm, flat or folded, abaxially glabrous, adaxially shallowly ribbed, ribs scaberulous; margins scaberulous, tip hooded. Culm 15-40 cm, erect or spreading, internodes glabrous. Panicle (1.5)-4-15 × 0.4-5-(7) cm, lanceolate, or narrow-oblong to ovate, usually contracted, sometimes more open; branches scabrid, all, or at least the shortest, bearing densely clustered spikelets to the base. Spikelets 3.5-5.5 mm, (3)-4-5-(8)-flowered, greyish green, often purple tinged. Glumes ± unequal, elliptic to ovate, obtuse to subacute, midnerve often finely scabrid above, apex minutely ciliate; lower 0.7-1.5-(1.8) mm, 1-nerved, upper 1.2-2 mm, 3-nerved. Lemma 1.7-2.6 mm, 5-nerved, with short hairs at base and on lateral nerves for a short distance above base or sometimes on lower half, elliptic-oblong, apex subobtuse, minutely ciliate, midnerve minutely scabrid near lemma apex, often minutely excurrent Palea ˜ lemma, apex shallowly bifid, keels ciliate-scabrid in upper ½ -⅔. Rachilla 0.4-0.8 mm. Anthers 0.5-0.9 mm. Caryopsis 1.2-1.5 × 0.4-0.6 mm.