Japan Flora: Tufted and rhizomatous; culms 30-60 cm. long, glabrous; leaves fascicled, the blades 3-5 mm. wide, flat，deep green, stiff, coriaceous, lustrous above, the margins prominently antrorsely scabrous on the upper half and retrorsely so on the lower half, the basal sheaths brown, dark brown fibrous; inflorescence much interrupted; spikes 斗-10, on simple or forked peduncles, soli­tary or ternate at each node, often all androgynous, 15-3 cm. long, the pistillate slightly shorter than the staminate, few­flowered, the bracts short-bladed, long-sheathing at base; pistil­late scales ovate, dark brown, obtuse; perigynia 5-6 mm. long, twice as long as the scale, obliquely spreading, obovate-fusi­form, plano-convex, many-nerved, sparsely hairy, gradually narrowed at both ends, with a short, recurved 2-toothed beak; stigmas 3. Apr.-May. Woods in hills and low mountains.

Honshu, Shikoku, Kyushu.