Japan Flora: Rhi­zomes short; culins tufted, sharply angled, scabrous; leaf­blades 2-4 mm. wide, thin, flat, bright green; inflorescence rather dense, looser toward base, the lowest bract setaceous; spik效 7-9, gynecandrous, each with a few staminate flowers at base, oblong to slenderly so, 3-4 mm. across, pale green; pistillate scales membranous, ovate, faintly nerved, acute and mucronate; perigynia slightly longer than the scales, plano­convex, ovate-lanceolate, thin, faintly nerved, about 4 mm. long, gradually long-beaked, scabrous and 2-toothed at apex; stigmas 2.  June-July. Wet grassy places in alpine and subalpine zones in the middle part of Honshu.