Rhizome neck 4–8 cm. Culms 3–7 m, 1.5–2.5 cm in diam.; internodes terete, 26–30 cm, initially white powdery; wall 4–8 mm thick or nearly solid; supra-nodal ridges level or weakly prominent; sheath scar prominent, initially pale yellow setose. Branches 4–23 per node. Culm sheaths triangularly narrowly rounded, shorter than internode, leathery, rigid, setose, proximally more densely so, longitudinal ribs prominent, margins densely ciliate, apex broadly triangular; auricles absent or small; oral setae few, 2–5 mm; ligule convex or concave, 1–3 mm; blade reflexed, narrowly triangular, margins apically rolled. Leaves 3 or 4 per ultimate branch; sheath glabrous; auricles absent; oral setae few, 3–6 mm; ligule convex, ca. 0.5 mm; blade linear-lanceolate, 4–9.5 × 0.8–1.2 cm, glabrous, secondary veins 3-or 4-paired, transverse veins distinct, base cuneate, margins spinescent-serrulate, apex long acuminate. Inflorescence unknown. New shoots Aug.