Thamnocalamus spathiflorus (Trin.) Munro

Rhizome neck 3.5–6 cm, 7–20 mm in diam. Culms 3–4 (–5.5) m, 1–2 cm in diam.; internodes terete or slightly flattened above branches, 15–18 cm, grooved, ridged, initially densely white powdery, glabrous; wall 2–3(–4) mm thick; nodes slightly to distinctly swollen; sheath scar prominent, with persistent remains of sheath base. Branches (1–)3–6, erect or deflexed, densely white powdery, glabrous. Culm sheaths deciduous, narrowly rounded or narrowly triangular-rounded, equal to or slightly longer than internodes, leathery, white powdery, glabrous or densely setose, margins yellow-brown ciliate, longitudinal ribs conspicuous; auricles absent or falcate, oral setae absent or prominent; ligule arcuate, ca. 1 mm, glabrous, margins fissured; blade erect, gray or gray-brown, triangular or linear-lanceolate, glabrous, margins usually rolled, serrulate. Leaves 2–5(or 6) per ultimate branch; sheath glabrous; auricles absent or prominent, oral setae absent, or many and readily deciduous, gray, 1–1.5 mm; ligule truncate, ca. 1 mm, margins puberulous; blade narrowly lanceolate, 4.5–9 × 0.5–1 cm, glabrous, secondary veins 2-paired, transverse veins distinct, base broadly cuneate or nearly rounded, margins serrulate. Inflorescence unknown from China. New shoots May–Jun.

S Xizang [Bhutan, NE and NW India, Nepal].

Coniferous and mixed subalpine forests; 2500–2900 m.