Rhizome neck (6–)10–18 cm, 4–15 mm in diam. Culms 2.5–3.5 m, 0.8–1 cm in diam.; internodes terete, 15–17(–20) cm, smooth, initially slightly white powdery, later white waxy, glabrous; wall 1.5–3.2 mm thick, pith thin and closely adnate to inner wall; supra-nodal ridges weakly prominent; sheath scar greatly prominent as a thick broad ridge, initially brown setose. Branches 6–16 per node, deflexed. Culm sheaths gradually deciduous, red-brown, narrowly triangular, much longer than internodes, basally leathery, distally more papery, sparsely brown setose, longitudinal ribs prominent, margins apically densely gray ciliolate; auricles and oral setae absent; ligule truncate or convex, ca. 1 mm, margins usually ciliolate; blade readily deciduous, reflexed, linear-lanceolate, glabrous, margins dentate-serrulate. Leaves 2–4 per ultimate branch; sheath abaxially glabrous, ridged, margins gray ciliate; auricles absent; oral setae few, erect, yellow, 1–1.5 mm; ligule arcuate, ca. 1 mm, glabrous; blade linear-lanceolate, 6–10 × 0.6–0.8 cm, proximally often slightly pilose, secondary veins 2- or 3-paired, transverse veins weakly prominent, base cuneate, margins spinescent-serrulate, apex long acuminate. Inflorescence unknown. New shoots Jun.