Japan Flora: Rhizomes tufted, sometimes creeping; culms 20-40 cm. long, 3-angled, almost smooth; leaves longer than the culms, the blades 6-7 mm. wide, rather thick, green, nearly glabrous, long-attenuate, the basal sheaths light brown, sparingly fibrous when withered or old; spikes 3 or 4, the terminal staminate^ linear, light brown, 2.5-3 cm. long, 2-2.5 mm. across, the lateral pistillate, erect, linear-cylindric, 1.5-2 cm. long, with a few staminate flowers at the apex, 5 mm. thick, the peduncles nearly included, the bracts spathaceous, 7-15 mm. long, pale green, with a setaceous short blade; pistillate scales oblong, very obtuse and mucronate, pale and slightly tinged with red, the midrib green, 3-nerved; perigynia about 3.5 mm. long, ovoid to ellipsoid, trigonous or lenticular, glabrous, pale green, many-ribbed, the beak smooth, short, hyaline, subentire; achenes narrowed above and crowned by a depressed disc about 0.7 mm. across at apex; stigmas (2-) 3. June.

Hon­shu (Hachijo Isl. in Izu).