Vines woody. Branches terete, often shallowly 4--10-grooved, puberulous, glabrescent. Leaves ternate; petiole 2.5--9 cm; leaflet blades ovate, rhombic-ovate, or elliptic, 1.8--7(--14) × 1--5 cm, papery to herbaceous, undivided or 3-lobed, both surfaces sparsely puberulous, base broadly cuneate to rounded, margin sparsely dentate or occasionally entire, apex acuminate or acuminate; basal veins abaxially nearly flat. Flowers (1 or)2--4(--6) borne together with several leaves from axillary buds of old branches, 1.5--11 cm in diam. Pedicel 1--20 cm, sparsely puberulous. Sepals 4, white or sometimes tinged pink, spreading, obovate to oblong-obovate, (0.7--)1.3--6.5 × (0.3--)1--2.5 (--3.5) cm, abaxially puberulous, adaxially glabrous, apex rounded to rarely emarginate or short acuminate. Stamens 6--18 mm, glabrous; anthers narrowly oblong, sometimes linear, (1.5--)2--3(--4) mm, apex obtuse to minutely apiculate. Ovaries glabrous, rarely puberulous. Style 0.5--1 cm, densely villous. Achenes ovate to rhombic-ovate, 4--5 × 3--4 mm, glabrous, rarely appressed puberulous; persistent style 2--6(--7) cm, plumose. Fl. Apr--Sep, fr. Jul--Sep.

Forests, forest margins, slopes, scrub, along streams; 1000--4000 m. S Anhui, NW Fujian, S Gansu, N Guangxi, Guizhou, SW Henan, Hubei, Hunan, Jiangxi, S Ningxia, E Qinghai, S Shaanxi, Sichuan, Taiwan, E and S Xizang, Yunnan, Zhejiang [Afghanistan, Bhutan, N India, Kashmir, N Myanmar, Nepal, N Pakistan, Sikkim].