Eriocaulon trilobum Buchanan-Hamilton ex Körnicke.

Leaves linear, 3--4.5 cm, ca. 3 mm wide at middle, veins ca. 10. Scapes 5--10, 10--15 cm; sheath ca. 4 cm; receptacle glabrous, slimy; heads black, subglobose, 3--3.5 mm; involucral bracts oblong-obovate, 1.5--1.9 × 1.2--1.4 mm, membranous, abaxially blackish toward apex, glabrous, apex truncate; floral bracts blackish, oblong to obovate, abaxially white clavate hairy toward apex. Male flowers: sepals spathelike, apex 3-cleft, posterior cleft blackish, flat, 1.6--1.8 mm, lateral clefts boatlike, abaxially hairy along midvein and at apex; petals 3, small, anterior one slightly larger than others, white clavate hairy toward apex, gland brown to black; anthers black, large. Female flowers: sepals 3, blackish, free, abaxially white clavate hairy toward apex, lateral ones boatlike, 1 or both narrowly keeled; petals 3, oblanceolate-linear, membranous, anterior one hairy adaxially and at apex, margin shortly hairy, apex emarginate, gland brown to black; ovary 3-loculed; style 3-parted. Seeds ovoid, ca. 0.5 mm; testa hexagonally reticulate, prickles 3 or 4 per cell, linear. Fl. and fr. Jul--Nov.

Valleys, ponds; 2300--2800 m. Guizhou, Sichuan, Xizang, Yunnan [Bangladesh, India, Indonesia, Nepal, Sri Lanka, Thailand].