Japan Flora: Rhizomes very short or nearly absent; culms erect, slightly compressed, 10-60 cm, long; leaves rather firm, 0.7-1 mm. wide, abruptly obtuse, glabrous; inflorescence of a single spikelet, rarely to 3, the bract wanting or 1, short, rarely to 5 cm. long; spikelet oblong to ovoid, 8-25 mm. long, 4-7 mm. thick, terete, lustrous, yellowish stramineous, partially reddish brown; scales rather firm, not keeled, elliptic, 4-6 mm. long, obtuse and mucronate; achenes obovate-orbicular, biconvex, dark brown at maturity, nearly smooth, distinctly stiped, the body 1-1.2 mm. long; stamens 3, the anthers linear, 1.2-1.8 mm. long. July-Oct. Rather common in wet places in mountains or in lowlands.
Hokkaido, Honshu, Shikoku, Kyushu. Korea, Manchuria, Ryukyus, Formosa, China, India, and Malaysia.
var. pacifica (Ohwi) Ohwi. Plant very slender; spikelet 7-15 mm. long, 2.5-3 mm. wide, paler, stramineous; scales membranous, 3-4 mm. long; stamens 2; otherwise as in the typical phase. Cliffs along seashores and in wet places in lowlands near the sea; Honshu (Hachijo Isl. in Izu), Shikoku, Kyushu; rare. Ryukyus.