Japan Flora: Culms slender, obtusely angled, smooth, 10-50 cm. long; leaves 1-2 mm. wide; corymbs simple, with 1-5 rays to 8 cm. long; bracts 2 to 4, the lower ones longer than the inflorescence; spikelets linear, 1-2.5 cm. long, 1-2.5 mm. wide, yellowish brown, strongly compressed; scales narrowly ovate, 1.5-2 mm. long, obtuse, entire; achenes 1/3-2/5 as long as the scale, biconvex, dark brown, obovate; sdgmas 2. Aug.-Oct. Wet places.
Honshu, Shikoku, Kyushu; common. Korea, Manchuria, China, Formosa, Malaysia, India, Australia, s. Europe, and tropical Africa.