棱纹玉山竹 leng wen yu shan zhu

Rhizome neck 20–50 cm. Culms 1.5–3 m, 4–15 mm in diam.; internodes terete, 13–37 cm, longitudinally ribbed, initially white powdery and brown clavate-setulose below nodes; wall 2–3 mm thick; supra-nodal ridges level or weakly prominent; sheath scar prominent. Branches 1 per node, about as wide as culm. Culm sheath persistent, narrowly triangularly rounded, short, leathery, densely appressed brown clavate-setose, margins brown ciliate; auricles readily deciduous, elliptic, small; oral setae 2–5, 2–4.5 mm; ligule truncate, ca. 1 mm, slightly hairy; blade reflexed, linear-lanceolate, erect or abaxially slightly hairy at base. Leaves 4–14 per ultimate branch; sheath margins glabrous; auricles absent; oral setae absent or few; ligule truncate; blade lanceolate, 16–25 × 1.6–2.5 cm, abaxially white-gray pubescent, secondary veins 5–7-paired, transverse veins distinct, base cuneate. Inflorescence unknown. New shoots Jul–Aug.

* About 1300 m. NE Yunnan.