Leaves linear, 10--35 cm × 2--3 mm, sparsely villous, veins 10--15. Scapes ca. 10, 15--75 cm, 5--7-ribbed; sheath 6--20 cm, villous; receptacle villous; heads subglobose, not compressed, ca. 6 mm in diam., glaucous, base truncate; involucral bracts reflexed, orbicular-reniform to ovate, 2--2.5 mm in diam., rigid, abaxially sparsely villous; floral bracts obovate, abaxially densely white clavate hairy toward apex. Male flowers: sepals spathelike, 2--2.3 mm, abaxially hairy toward 3-lobed apex, posterior lobe linear, glabrous, lateral lobes boatlike, winged; petals 3, linear, white clavate hairy at apex, gland black, ovate; anthers black. Female flowers: sepals 3, free, 2--2.3 mm, posterior one linear, glabrous, lateral ones broadly winged, pubescent; petals 3, linear, fleshy, villous at center, white clavate hairy at apex, gland black, elliptic; ovary 3-loculed; style 3-cleft. Seeds ovoid, 0.6--0.8 mm; testa hexagonally reticulate, prickles 1 or 2 per cell, T-shaped. Fl. and fr. summer to autumn.

Ponds, marshlands, sandy soil; 100--2000 m. Fujian, Guangdong, Jiangxi, Yunnan [Cambodia, W Malaysia, Thailand, Vietnam; Australia, Pacific Islands].