Japan Flora: Rhizomes abbreviated; culms distinctly compressed to ancipital above, glabrous, 20-80 cm. long; leaves flat, 1.5-3 mm. wide, glabrous, abruptly acuminate, the sheath distichous, minutely ciliate along the dorsal margin of the mouth; inflorescence umbelliform, compound, 2 to 7(-10) cm. long, the bracts linear, shorter than the inflorescence; spikelets numerous, broadly lanceolate to narrowly ovate, 5-8 mm. long, 1.5-2 mm. wide, acute, angled; scales membranous, oblong, about 3 mm. long, acute, reddish brown, keeled; achenes about 1 mm. long, whitish, smooth or sparsely verrucose, the reticulations transversely oblong, not elevated; stamens 3, the anthers linear, about 15 mm. long.            July-Oct.

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