Rhizome neck 4–13 cm, 7–10 mm in diam., internodes 2–8 mm. Culms 3–5 m, 0.6–1.3 cm in diam.; internodes terete, 15–18 cm, smooth, initially slightly white powdery; wall 2–3 mm thick; nodes with level or prominent supra-nodal ridge on branching nodes; sheath scar prominent. Branches 4–15 per node, slender. Culm sheaths deciduous, light yellow, oblong-ovate, ca. 2/3 as long as internodes, leathery, glabrous, longitudinal ribs conspicuous; auricles and oral setae absent; ligule truncate, ca. 0.7 mm, glabrous; blade reflexed, linear or linear-triangular, glabrous. Leaves 2–5 per ultimate branch; sheath glabrous; auricles and oral setae absent; ligule truncate or arcuate, ca. 1 mm, glabrous; blade linear-lanceolate or lanceolate, 7–11 × 0.4–1 cm, glabrous, secondary veins 3- or 4-paired, transverse veins distinct, base cuneate or broadly cuneate, margins smooth or spinescent-serrulate initially. Inflorescence racemose, subtended by 1–4 purple spathes; spikelets 5–10, 1.5–2.5 cm, unilateral, rachilla internodes 0.5–1 mm; florets 2–4. Glumes narrowly lanceolate, papery, abaxially puberulous at apex; lemma ovate-lanceolate, puberulous, apex mucronate to long mucronate; palea keels serrulate, apex bifid; lodicules ovate. Anthers yellow. Ovary ovoid, glabrous; style 1; stigmas 3. Caryopsis ovoid. New shoots May.

The shoots are fragrant and are eaten by the giant panda.

* 1900–3200 m. S Gansu, N Sichuan.