Rhizome neck 10–13 cm, 1–2 cm in diam. Culms 2–4 m, 1–2 cm in diam.; internodes terete, 11–20 cm, initially sparsely white powdery, glabrous; wall 2–3 mm thick; supra-nodal ridges weakly prominent; sheath scar prominent. Branches 15–18 per node, deflexed. Culm sheaths persistent, purple or purple-brown, triangular-elliptic, usually longer than internodes, leathery, glabrous or sparsely white-gray setose, longitudinal ribs prominent, margins glabrous, apex triangular; auricles and oral setae absent; ligule purple, arcuate, ca. 1 mm, margin densely ciliolate; blade reflexed or erect, triangular or linear-lanceolate. Leaves 2 or 3 per ultimate branch; sheath purple, margin densely gray-brown ciliate apically; auricles absent; oral setae absent or obscure; ligule truncate or arcuate, ca. 1 mm, margin initially white ciliolate; blade linear-lanceolate, 3.8–7.5 × 0.6–1 cm, glabrous, secondary veins 3-or 4-paired, transverse veins distinct, base cuneate, one margin spinescent-serrulate, other margin obscure. Inflorescence a raceme, subtended by 1–3 spathes; spikelets 1.1–2.5 cm; rachilla 1.5–3 mm; florets 2 or 3. Glumes 1 or 2, leathery, apex acuminate or obtuse; lemma slightly setulose, apex obtuse; palea sparsely setose, keels serrulate, apex bifid; lodicules ciliate. Anthers yellow. Ovary ovoid, glabrous; style 1; stigmas 3. Caryopsis yellow-brown to dark brown, ovoid, glabrous. New shoots late Apr–May.