Description from Flora of China
Ischaemum zeylanicum Hackel ex Trimen, Syst. Cat. Pl. Ceylon 107. 1885.
Perennial, tufted. Culms erect, slender, branching, 20–60 cm tall. Leaves mostly basal, slightly overlapping; leaf sheaths glabrous, keeled; leaf blades flat or folded, (1–)3–10 × 0.1–0.5 cm, glabrous, apex rounded, cuspidate; ligule 0.3–0.6 mm, ciliolate or glabrous. Raceme erect or curved, 3–6 cm; rachis internodes clavate, 2–3 mm; nodes minutely hairy, hairs ca. 0.1 mm. Sessile spikelet 4–5 mm; lower glume elliptic-ovate, papery, glabrous, inconspicuously veined, marginal spines terete, equaling or much longer than glume width, 1.5–2.5 mm, apex acute, flanked by narrow wings. Pedicelled spikelet a very small rudiment; pedicel subulate.
A few specimens from China have the long spikelet spines of this species, which is otherwise known only from Sri Lanka.
Herbage of hill slopes; 800–1500 m. W Guangxi, SE Yunnan [Sri Lanka].