Perennial, 60-150 cm. Rhizome short, horizontal, covered by brown or dark-brown scales. Stem 2-8 mm diam., trigonous, edges obtuse below, smooth, sides in upper part often concave. Leaves basal, shorter than stem; sheaths up to 20 cm, yellowish or brown, soft, one side scarious, mouth margin concave; blades 50 cm or longer, 6-12 mm wide, flat or folded, keeled, margins narrowly revolute, smooth or distally scabrous, apex long-attenuate, trigonous, scabrous. Inflorescence a compound anthelodium, 10-25 cm; bracts, 6-9 lowermost leaf-like, longest more than 50 cm; primary branches mostly 6-9, to 15 cm, with tubular prophyll up to 20 mm; secondary anthelodia 4-10 cm; cluster of spikes 30-50 mm long, with 30-60 spikes; spikes spirally arranged, reflexed, 7-13 x c. 2 mm, glume-like bract 1.5-2 mm, acute, glume-like prophyll 1.6-2 mm, binerved; rachis rigid, flat, reddish brown, internodes c. 1 mm; glumes 2.5-2.8 mm, acute, midnerve area green, sides with 2-3 conspicuous veins and often with reddish-brown zone, margins widely scarious, basal edges extending down to next node. Nut 1.3-1.5 x 0.4-0.5 mm, ovoid, trigonous, grey-brown, very finely reticulate.

Fl. Per.: July-August.

Type: "East India", Roxburgh; ex Hrb. Forsyth in Hrb. Bentham, (K!).

Open wet places, swamps, rice fields; Distribution: Pantropical; in SE Asia from Pakistan, India and Sri Lanka to S. China, Philippines, Malaysia and SE Australia.