Vines woody, turning black on drying. Branches shallowly 8--10-grooved, sparsely puberulous, glabrescent. Leaves pinnate or 2-pinnate, 5--11-foliolate; petiole 1.2--5.5 cm; leaflet blades ovate, triangular-ovate, or lanceolate, 1.2--7.8 × 0.5--3 cm, papery, undivided or sometimes 3-lobed, both surfaces subglabrous to sparsely puberulous on veins, base cuneate, rounded, or subcordate, margin entire, apex acute, attenuate, or acute; basal veins abaxially ± prominent. Cymes axillary or terminal, 1--3(--5)-flowered; peduncle 1--7.6 cm, sparsely puberulous; bracts often petiolate, ovate, narrowly ovate, or elliptic, 0.8--5 cm, rarely ternate. Flowers 2.5--4.8 cm in diam. Pedicel 3--8 cm, subglabrous to sparsely puberulous. Sepals (4 or)5 or 6(or 7), white, spreading, oblong, obovate-oblong, or lanceolate, 1.2--2.6 × 0.4--0.8 cm, abaxially glabrous except for velutinous margin, adaxially glabrous, apex acute to obtuse. Stamens 5--8 mm, glabrous; anthers linear, 3.8--4.5 mm, often longer than filaments, apex minutely apiculate. Ovaries densely pubescent. Style ca. 4 mm, densely villous. Achenes elliptic to ovate, 4.5--5 × 2.8--3 mm, appressed pubescent; persistent style to 2.5 cm, brown-yellow plumose. Fl. Apr--Jun, fr. Aug--Nov.