Rhizome neck 4–20 cm; internodes solid. Culms to 4.5 m, 1–2 cm in diam.; internodes terete, 25–40 cm, glabrous or initially distally brown setulose; wall 2–3.5 mm thick; nodes with level supra-nodal ridge; sheath scar prominent, glabrous or initially slightly setose. Branches 10–19. Culm sheaths gradually deciduous or persistent, triangularly narrowly rounded, shorter than internode, leathery, prominently longitudinally ribbed, brown to dark brown setose, margins densely brown ciliolate; auricles absent; ligule arcuate, ca. 1 mm; blade readily deciduous, revolute. Leaves 2–4 per ultimate branch; sheath glabrous; auricles absent; oral setae few, 2–4 mm; ligule truncate or convex, glabrous, margins slightly fissured; blade narrowly lanceolate, 3–11 × 0.5–0.8 cm, secondary veins 3- or 4-paired, transverse veins distinct, adaxially and basally sparsely setose, base cuneate or broadly so, margins serrulate. Inflorescence unknown.

* About 2400 m. S Xizang.