Perennial, loosely tufted with scaly rhizomes. Culms erect, 0.6–1.2 m tall, 2–5 mm in diam., internodes glabrous, 3-noded, nodes blackish, bearded or glabrous. Leaf sheaths with tubercle-based hairs when young, glabrescent; leaf blades linear-lanceolate, flat, rather rigid, 10–30 cm × 5–14 mm, glabrous on both surfaces, lacking an obvious midvein, margins scabrid or tuberculate-ciliate, apex acuminate; ligule ca. 0.5 mm. Panicle contracted, lanceolate in outline, 10–30 cm; central axis smooth, glabrous; branches up to 10(–15) cm, single or paired, densely spiculate, usually with branchlets; pedicels smooth. Spikelets 6–7 mm, purple or purplish red; glumes glabrous, smooth or veins scabrid; lower glume 3.8–4.5 mm, (3–)5(–7)-veined; upper glume as long as spikelet, 5-veined; lower floret staminate or barren, slightly longer than lower glume; upper floret 3–3.5 mm, lemma scabrid on back, apex awned; awn geniculate with brown twisted column, 5–6 mm; callus hairs ca. 1/3 length of lemma. Fl. and fr. Jul–Sep.