Vines woody. Branches inconspicuously 4--6-angulate to subterete, glabrous; bud scales deltoid, triangular, or oblong, 0.4--1.8 cm, abaxially apically puberulous. Leaves 2-ternate; petiole 3--6.5 cm; leaflet blades elliptic-ovate, ovate, or lanceolate, 2--7 × 1.1--3 cm, herbaceous to thin papery, both surfaces sparsely puberulous or adaxially glabrous, base broadly cuneate to rounded, margin serrate to denticulate, apex acute to acuminate; basal veins nearly flat. Flowers solitary, 3--6 cm in diam. Pedicel 7--10(--14) cm, sparsely puberulous. Sepals 4, yellow, yellowish, white, purple, or blue, ascending, narrowly oblong, oblong, narrowly ovate, or oblong-obovate, 2.2--4.5 × 1--2 cm, both surfaces puberulous or adaxially glabrous, abaxially margin densely puberulous, apex acute to acuminate. Staminodes linear-spatulate, ca. 1/2 as long as sepals, 2--5 mm wide, abaxially puberulous, adaxially glabrous. Stamens 1--1.4 cm; filaments puberulous; anthers narrowly oblong, 2--3.2 mm, abaxially puberulous on connective. Ovaries puberulous. Style 8--9 mm, densely villous. Achenes obovate, 4--5 × 3--4 mm, puberulous; persistent style 2.5--4.5 cm, plumose. Fl. May--Jul, fr. Jul--Aug.

Forests, forest margins, scrub; 600--2000 m. C Gansu, N Hebei, Heilongjiang, Jilin, Nei Mongol, Ningxia, E Qinghai, N Shanxi, Xinjiang [Japan, Mongolia, Russia; NW Europe].