Description from Flora of China
Annuals or short-lived perennials. Rhizomes absent. Culms sparsely tufted, 6-35 cm tall, thin, slightly compressed, striate, smooth, glabrous. Leaves bladeless; basal sheaths glumelike; apical sheaths cylindric, apex obliquely truncate. Involucral bracts absent. Inflorescences reduced to a single terminal spikelet, ovoid to narrowly ovoid, 5-10 × 2-3 mm, with several to 10 or more flowers. Glumes laxly spirally imbricate, greenish white and sometimes laterally with brown specks, broadly ovate to elliptic, 2.8-4 mm, thickly papery, with several faint veins forming an abaxial green keel, apex obtuse and mucronate. Stamens 2; anthers linear. Style long and compressed, sparsely ciliate, basally inflated; stigmas 2, straight. Nutlet with a short brown stipe, globose-obovoid, ca. 1.5 mm, biconvex, with transverse wavy reticulation. Fl. and fr. Jul-Aug.
Open wet places, sandy soil grasslands, watersides, grasslands by water; low elevations. Fujian, Guangdong, Hainan [India, Indonesia, Japan (Ryukyu Islands), Laos, Malaysia, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Australia].