Rhizome neck 3–5 cm. Culms 2.5–6 m, 1–2.5 cm in diam.; internodes terete, 22–28 cm, densely and prominently longitudinally ribbed, initially densely white powdery, white-gray setulose below node; wall 3.5–6 mm thick; supra-nodal ridges weakly prominent; sheath scar prominent. Branches 5–10 per node, nearly solid. Culm sheaths persistent, narrowly triangular, shorter than internode, leathery, proximally densely gray setose, margins glabrous, apex triangular; auricles absent; oral setae absent or few, yellow, 2–6 mm; ligule truncate or arcuate, 1–2 mm, glabrous; blade reflexed, linear-lanceolate. Leaves 2–4 per ultimate branch; sheath glabrous; auricles and oral setae absent; ligule arcuate or truncate, ca. 0.5 mm, glabrous; blade narrowly lanceolate, 4–8.5 × 0.6–0.8 cm, glabrous, secondary veins 3- or 4-paired, transverse veins slightly distinct, base cuneate, margins nearly smooth, or one margin spinescent-serrulate and other margin smooth, apex long acuminate. Inflorescence unknown. New shoots late Aug–early Sep.

* About 2900 m. SW Yunnan.