Leaves linear, 8--15 cm, 4--5 mm wide at middle, veins 12--20. Scapes ca. 30, 14--20 cm, 3--5-ribbed; sheath 5--8 cm; receptacle glabrescent, occasionally with some short hairs; heads straw-colored at base, black at apex, turbinate, 3--4 × 4--6 mm; involucral bracts yellowish green, ovate, 1.5--2(--3.8) × 1.2--2(--2.6) mm, usually silky, glabrescent; floral bracts obovate to oblanceolate, glabrescent. Male flowers: sepals spathelike, 1.4--2 mm, glabrescent, apex 3-lobed or truncate; petals 3, subulate, subequal, fleshy, glabrescent, gland black; anthers black. Female flowers: sepals black, spathelike, 1.8--2.2 mm, glabrescent, basally connate, apex 3-lobed; petals 3, spatulate, fleshy, adaxially villous, glabrous at apex, gland black; ovary 3-loculed; style 3-cleft. Seeds narrowly ovoid, 0.7--0.8 mm; testa hexagonally reticulate, prickles 1 or 2(--4) per cell, T-shaped or linear. Fl. and fr. Aug--Nov.

Rice fields, damp soil, near marshes; near sea level to 3500 m. Anhui, Guizhou, Heilongjiang, Hubei, Jiangxi, Liaoning, SW Sichuan, Xizang, Yunnan [Bhutan, India, Japan, Korea, Nepal, Philippines, Sikkim, Thailand].