Japan Flora: Rhizomes tufted; culms slender, erect, 20-60 cm. long, glabrous; leaf­blades glaucous, somewhat soft, nearly glabrous, 3-5 mm. wide, densely puncticulate, the sheaths light ferrugineous, thinly membranous, the ligule light ferrugineous and very thin; spikes 3 or 4, erect, the terminal staminate, linear, sessile, 1-3 cm. long, light ferruneous, the lateral pistillate, cylindric, densely many-flowered, erect, 1-4 cm. long, the upper ones nearly sessile, the lower long-peduncled, the lower bracts leaf­like, longer than the culm, long-sheathing; pistillate scales nar­rowly ovate, obtuse, pale ferrugineous; perigynia much longer than the scales, 2.5 mm. long, broadly ellipsoidal, ascending, compressed-trigonous, grayish green, frequendy brownish when dried, densely papillose, with several raised nerves, rounded and abruptly short-beaked, the mouth ferrugineous, hyaline, entire; stigmas 3, short.  May-June. Wet places in lowlands.

Honshu, Shikoku, Kyushu. s. Korea, Ryukyus, Formosa, China, and India.