Japan Flora: Culms slender, 30-60 cm. long, smooth, very loosely few-leaved; leaves 2-3.5 mm. wide; corymbs 3-5, erect, interrupted, the peduncles unequal; spikelets broadly lanceolate, 7-8 mm. long, with 4 or 5 scales, usually 2-flowered, dark brown; achenes broadly obovate, glabrous, 2-2.2 mm. long, with inconspicuous transverse wrinkles, the beak slightly shorter than the achene, dekoid, flattened, glabrous; bristles 6, slender, 4-5.5 nun. long, antrorsely scabrous. July-Oct. Wet and swampy places.
Honshu (centr. distr. and westw.), Shikoku, Kyushu. Korea, Ryukyus, Formosa, China, India, and Malaysia.