Herbs perennial, weak, glabrous, dioecious, rarely monoecious. Tuber brownish, conic, 5-10 × 3-4 mm, sometimes underground internodes becoming a tuber. Stems often simple, thin, 3-12 × 0.1 cm, succulent. Leaves crowded at stem apex, opposite or 4-6 in whorl; stipules persistent, deltoid, ca. 1 mm, membranous, apex obtuse; petiole unequal in length, 0.1-0.7 cm; leaf blade ovate to ovate- or elliptic-lanceolate, unequal in size, 0.8-4 × 0.5-1.4 cm, submembranous, 3-veined, lateral veins several, reticulate, glabrous, adaxial surface sometimes sparsely pilose on veins, cystoliths fusiform, slightly conspicuous abaxially, base cordate or obtuse, margin sharply serrate, often with a glandular dot by tooth tip abaxially, apex acuminate, sometimes acute. Inflorescences solitary, in upper nodes, a capitulum, peduncle slender, 0.5-2 cm; of several unisexual or rarely bisexual flowers, female peduncle 0.2-2 cm. Bisexual flowers: perianth lobes 3; ovate, ca. 1.5 mm, stamens 3; ovary ellipsoid, ca. 0.8 mm. Male flowers: pedicel 1-1.5 mm; in bud ca. 1.8 mm; perianth lobes (3 or)4, ovate, connate 1/2 of length, subapically corniculate, stamens (3-)4; rudimentary ovary narrowly conic. Female perianth lobes unequal, largest lobe 1/2 as long as achene, subapically corniculate. Achene obliquely ovoid, 1-1.2 mm, slightly compressed, smooth, enclosed by persistent perianth. Fl. Jun-Jul, fr. Jul-Sep.

Abies and Rhododendron forests, shaded moist places, mossy rocks, wet mossy trees; 2500-3500 m. S Xizang, NW Yunnan [Bhutan, Nepal, Sikkim].