Japan Flora: Rhizomes tufted; culms 15-30 cm. long, capil­lary, smooth; leaf-blades 0.3-1 mm. wide, sometimes flattish, at least the outer always filiform-involute, the sheaths stramin­eous green; spikes 2 or 3, erect, the terminal staminate, linear, often slightly brownish, 1-1.5 cm. long, the others pistillate, short-cylindric, loosely few-flowered, 7-15 mm. long, on short usually included peduncles, the lowest one sometimes slightly exserted, the lowest bract somewhat leaflike, longer than the spike, long-sheathing; perigynia 2.5-35 mm. long, glabrous. Apr.-June. Woods in hills and mountains.

Hokkaido, Honshu, Shikoku, Kyushu; rather common. Formosa.