Vines woody. Branches not grooved or very shallowly 4--8-grooved, sparsely puberulous, glabrescent. Leaves ternate; petiole 2--3(--6) cm; leaflet blades narrowly ovate, lanceolate, or elliptic, rarely linear-lanceolate, 2--8.5(--11) × (0.3--)0.8--3.5(--5) cm, subleathery, abaxially sparsely puberulous or glabrous, adaxially glabrous, base broadly cuneate to rounded, margin entire, apex acuminate; basal veins nearly flat. Flowers usually 2--4, sometimes borne together with 2 to several leaves from axillary buds of old branches, 1.4--1.7 cm in diam. Pedicel 0.5--2.4 cm, yellowish velutinous. Sepals 4, white, erect, obovate-oblong to suboblong, 1.2--2 × 0.5--0.8 cm, abaxially yellowish velutinous, adaxially glabrous, apex ± obtuse. Stamens 0.9--1.4 cm, glabrous; anthers narrowly oblong, 3--3.2 mm, apex obtuse. Ovaries glabrous. Style 0.9--1.2 cm, densely villous. Achenes lanceolate, 5.5--8 × 1.5--3 mm, glabrous; persistent style 1--1.6 cm, plumose. Fl. Dec--Mar, fr. Jul--Oct.

Forests, scrub, along streams, stony slopes; 1500--3500 m. W Guangxi, SW Guizhou, SW Sichuan, Yunnan [N Myanmar, N Vietnam].