Perennial, densely tufted. Culms 50–100 cm tall, 3–4-noded, lower nodes concealed. Basal leaves often reaching to panicle, leaf sheaths smooth or scabrid, lower longer than internodes; leaf blades filiform, convolute, up to 50 cm, outer surface smooth; ligule of basal leaves rounded, 0.5–1 mm, ciliate, of culm leaves lanceolate, 2.5–10 mm. Panicle narrow, 20–50 cm, base enclosed by expanded uppermost leaf sheath. Spikelets greenish purple; glumes narrowly lanceolate, 3–4.5 cm, apex filiform; callus pungent, 4–4.5 mm; lemma 15–17 mm, shortly hairy in longitudinal lines, a ring of short hairs at awn articulation; awn deciduous, 20–28 cm, scabrid, 2-geniculate, column 7–10 cm to first bend, 2–2.5 cm to second bend, bristle curling, 11–18 cm. Fl. and fr. May–Aug.