Perennial, erect or prostrate tufts, 8-80 cm; branching intravaginal. Leaf-sheaths smooth, firmly membranous, light brown, sometimes purplish near base; ligule 1-1.5-(2) mm, entire and rounded across top, rarely tapered and subacute; leaf-blades 3—6.5—(12) × 1—3 mm, flat, or folded with inrolled margins, abaxially smooth, adaxially shallowly ridged and scabrous on ridges, margins sparsely scabrous, tip scabrous, acute or hooded. Culms (5)-10-60 cm, enclosed by uppermost leaf-sheaths at flowering, later visible, smooth. Panicle (3)-10-24 × 2-18 cm, ovate to ± triangular, very lax and open; branches finely scabrous, bare below, later spreading to deflexed. Spikelets 3-6 mm, 3-7-flowered, greenish or purplish. Glumes ± unequal, minutely scabrous across obtuse tip; lower glume 0.7-1.2 mm, 1-nerved, elliptic-lanceolate; upper glume 1.1— 1.8 mm, 3-nerved, ovate. Lemma 1.5—2.4 mm, indistinctly 5-nerved, with short hairs at base and on nerves near base, broad-elliptic or ovate, ± membranous with nerves not reaching upper wide hyaline margin, minutely ciliate across broadly obtuse to almost truncate tip. Palea ± = lemma, tip shortly bifid, keels ciliate-scabrous in upper 2/3. Rachilla 0.6- 0.8 mm. Anthers 0.6-1 mm. Caryopsis 1-1.7 × 0.3- 0.6 mm. 2n = 42. Naturalised from Eurasia.

Perennial, erect or prostrate tufts, 8-80 cm; branching intravaginal. Leaf-sheath glabrous, firmly membranous, light brown, sometimes purplish near base. Ligule 1-1.5-(2) mm, entire and rounded, rarely tapered and subacute. Leaf-blade 3-6.5-(12) × 1-3 mm, flat, or folded with inrolled margins, abaxially glabrous, adaxially shallowly ribbed, ribs scabrid; margins sparsely scabrid, tip scabrid, acute or hooded. Culm (5)-10-60 cm, enclosed by uppermost leaf-sheath at flowering, later visible, internodes glabrous. Panicle (3)-10-24 × 2-18 cm, ovate to ± triangular, very lax and open; branches finely scabrid, naked below, later spreading to deflexed. Spikelets 3-6 mm, 3-7-flowered, greenish or purplish. Glumes ± unequal, minutely scabrid at obtuse apex; lower 0.7-1.2 mm, 1-nerved, elliptic-lanceolate, upper 1.1-1.8 mm, 3-nerved, ovate. Lemma 1.5-2.4 mm, indistinctly 5-nerved, with short hairs at base and on nerves near base, broad-elliptic or ovate, ± membranous with nerves not reaching wide hyaline upper margin; apex minutely ciliate, broadly obtuse to almost truncate. Palea ≈ lemma, keels ciliate-scabrid in upper ⅔, apex shortly bifid. Rachilla 0.6-0.8 mm. Anthers 0.6-1 mm. Caryopsis 1-1.7 × 0.3-0.6 mm.