Japan Flora: Rhizomes loosely tufted; culms 5-40 cm. long; leaf-blades flat, rather thick, glabrous, deep green, broadly linear, 8-12 mm. wide, the basal sheaths pale; spikes 2-4, the terminal lincar-clavate, 1-2 cm. long, the others pistillate, oblong, peduncled, rather densely flowered, the lowest bract leaflike, long-sheathing; pistillate scales elliptic, rounded at the apex and mucronate, pale green; perigynia longer than the scales, 5-6 mm. long, obliquely spreading, broadly ellipsoid, loosely pubescent, inconspicuously 3-angled, green, abruptly short-beaked, with a hyaline emarginate tip; achenes ellipsoid, with a short annulate beak, 3-angled, each angle with a con­striction near the middle; stigmas 3.  May-June. Woods and thickets in low mountains.

Hokkaido, Honshu (Japan Sea side in n. and centr. distr.). s. Kuriles.

var. papillaticulmis (Ohwi) Ohwi. Leaves 4-8 mm. wide; terminal spike linear; perigynia rather long-beaked. Honshu (Pacific side of centr. part and Kinki Distr.), Shikoku, Kyushu.

var. subdita (Ohwi) Ohwi. Plant slender; leaf-blades 2-4 mm. wide, paler green; perigynia 5-6 mm. long. Woods on hillsides; Honshu (Tokaido and s. Kinki Distr.), Shikoku.