Rhizome neck more than 37 cm; internodes solid, 6–10 mm in diam. Culms 3–5 m, 1–2.5 cm in diam.; internodes terete, 25–40 cm, not ribbed, initially thickly white powdery below nodes, glabrous, nearly solid; supra-nodal ridge weakly prominent; sheath scar prominent. Branches 5–8, deflexed. Culm sheaths persistent, triangularly narrowly rounded, shorter than internodes, prominently longitudinally ribbed, leathery, with densely appressed brown clavate-setose, margins glabrous; auricles absent; oral setae absent or present; ligule convex or truncate, 1–3 mm, sparsely ciliate; blade easily deciduous, linear-lanceolate, glabrous, margins serrulate, revolute. Leaves 4–6 per ultimate branch; sheath purple or purple-green, glabrous; auricles absent; oral setae absent or rarely present; ligule arcuate, 1–2 mm, glabrous; blade lanceolate, 7.5–15.5 × 1.2–2.1 cm, glabrous, secondary veins 3–5-paired, transverse veins slightly visible, base cuneate, one margin serrulate, other obscurely so. Inflorescence unknown. New shoots Aug–Sep.