Tufted perennial 25-40(-85) cm high. Leaf-blades involute and setaceous, up to 1.5 mm wide when flattened, smooth and glabrous on the lower (outer) surface; ligule 2-4 mm long. Panicle narrow, linear, few-flowered, 14-18(-30) cm long, with short stiff rigidly erect branches. Glumes lanceolate, shortly acuminate, 12-16 mm long, deeply suffused with purple, 3-nerved; lemma terete, 7-8 mm long (including callus), shortly pubescent all over, often with a crown of hairs at the tip; callus acuminate, pungent, 1-3 mm long. Awn bigeniculate, articulated at the base, 3.5-6 cm long, plumose throughout its length with hairs 1-1.5 mm long.