Rhizome neck more than 20 cm; internodes solid. Culms to 3 m, 0.5–1 cm in diam.; internodes terete, 25–40 cm, conspicuously longitudinally ribbed, glabrous, initially with white powdery ring below each node, nearly solid; supra-nodal ridges weakly prominent; sheath scar weakly prominent. Branches 6–10 per node. Culm sheaths persistent, narrowly triangular, 1/3–1/2 as long as internodes, leathery, conspicuously longitudinally ribbed, glabrous or sparsely brown setulose, margins initially densely brown setulose, longitudinal ribs prominent; auricles absent; oral setae 2–8, erect, yellow-brown, 5–10 mm; ligule truncate or convex, ca. 1 mm, glabrous; blade linear-lanceolate, revolute, glabrous, margins serrulate. Leaves 2–5 per ultimate branch; sheaths glabrous; auricles absent; oral setae absent or initially 1–3, gray, 2–3 mm; ligule truncate, glabrous; blade lanceolate, 11–22.5 × 1.2–1.8 cm, glabrous, secondary veins 4- or 5-paired, transverse veins not prominent, base cuneate, one margin serrulate, other margin obscurely so. Inflorescence unknown. New shoots Jul–Aug.

* About 2200 m. SW Sichuan.