Culms 8–10 m, 4–5 cm in diam., basally slightly flexuose, apically slightly drooping; internodes 30–35 cm, basal ca. 3 usually with purple streaks, with rings of brown silky hairs below and above sheath scars; wall thick; branching from base. Branches solitary on basal nodes, 3 to many on other nodes; branchlets of lower branches sometimes shortened into weak thorns. Culm sheaths deciduous, ribbed-striate when dry, densely stiffly dark brown strigose, apex usually subtruncate; auricles unequal, larger auricle to 1.5 × size of smaller one, elliptic, usually wrinkled, ca. 1 cm; oral setae ca. 1 cm; ligule ca. 3 mm, finely dentate and fimbriate; blade erect, ovate-triangular to narrowly ovate, base ca. 3/4 width of sheath apex, glabrous or abaxially sparsely stiffly dark brown strigose. Leaf blade linear-lanceolate, 8–14 × 1.1–1.5 cm, abaxially densely pubescent, adaxially sparsely pilose near base. Inflorescence unknown.

* Low hills. Hainan.