Japan Flora: Culms tufted, 5-15 cm. long, soft; leaves 3-5 cm. long, filiform, flaccid, 0.25-0.5 mm. wide; inflorescence umbelliform, nearly simple, bearing to 20 spike­lets, the bracts 3-10, filiform, the lower 1 or 2 longer than the inflorescence; spikelets ovoid-globular to oblong, pale green, 3-6 mm. long, 2-2.5 mm. across, densely many-flowered; scales oblong, thin-membranous, about 1 mm. long, obtuse and awned; achenes narrowly oblong, 0.7 mm. long, short-stiped, with 4-6 clavate-globular tubercles along the margins, the reticulations oblong-hexagonal.      Wet places in lowlands. 

Honshu, Shikoku, Kyushu. s. Korea, Manchuria, Amur, and Ussuri