Rhynchospora rubra (Lour.) Makino

Perennial (always?), with short rhizome; stolons wanting. Stems tufted, slender, trigonous, or triquetrous in the upper part, striate, smooth, 25-70(-120)cm by 1-2(-3)mm. Leaves basal and 1-2 cauline at the base of the stem, much shorter than to as long as the stems, rather rigid, keeled, gradually attenuate, scaberulous on the margins near the apex, 2-3(-5) mm wide. Inflorescence capitate, globose, dense, 1-1½ cm across. Involucral bracts 4-8, rigid, unequal, patent, finally reflexed, not sheathing, densely ciliate at the dilated base, exceeding the inflorescence, the lowest keeled by the strong midnerve, up to 7½ cm long. Spikelets ovate-lanceolate, compressed, acuminate, (2-)3(-4)-flowered, reddish-brown, 5-8 mm long; lower flower ♀ (very rarely with a single stamen), upper one(s) ♂. Glumes 6-8, chartaceous, distichous, keeled, acute or minutely mucronulate, the nutbearing one c. 2 mm longer than the next lower one. Bristles in the female flower 3-6, thin, whitish, antrorsely scabrous,often ciliate or shortly plumose at the base, usually shorter than the nut (see note), in the lowest ♂ flower 0-3, in the other flowers absent. Stamens (2-)3; anthers destitute of pollen at the base, 2-3 mm long. Style very long, shortly bilobed. Style-base shortly pyramidal, usually much depressed (broader than high) and suddenly dilated at the base, much narrower than the nut (c. ½ mm wide), puncticulate, stramineous. Nut broadly obovate, rarely oblongobovate, laterally compressed, turgidly biconvex, castaneous, acutely margined, minutely puncticulate, scabrous at the apex (more rarely all over), 1¼-1¾ by 1-1½ mm; epidermal cells minute, isodiametric.

In dry open countries, on road-sides and grassy hills, in lalang-fields, in savannah-forests, at low and medium altitudes, in Java up to 400 m, in Sumatra up to 1300 m, in New Guinea up to 1000 m.