Japan Flora: Rather soft perennial; culms 10-30 cm. long, slightly curved, smooth, densely pilose; leaves flat, 2-3 mm. wide, abruptly acute, pilose, the sheaths acutely angled, wingless, pilose; partial panicles 3-5, bearing rather few spikelets, 7~15 mm. long, on arcuate or declined pedun­cles; spikelets 2-4 mm. long; achenes whitish, lustrous, globose, 1.5 mm. across, glabrous, with coarse somewhat imperfect reticulations; hypogynium appressed, the lobes deltoid, very obtuse, slightly thickened on margin, flat, with a somewhat elevated longitudinal line in the center. July.-Oct. Wet places; Honshu (Kadzusa Prov. and westw.), Shikoku, Kyu­shu; rare. Ryukyus, Formosa, China, India, Ceylon, Aus­tralia, and Malaysia.

var. glabrescens (Koidz.) Ohwi & T. Koyama. Nearly glabrous throughout一July-Oct. Wet places; Honshu, Shikoku, Kyushu; very  rare. s. Korea.