Vines woody. Branches shallowly 6--8-grooved, puberulous, often glabrescent. Leaves ternate; petiole 2--6 cm; leaflet blades narrowly ovate to broadly lanceolate, 5--12 × 1.5--5 cm, papery, both surfaces sparsely puberulous, base rounded, margin denticulate, apex acuminate; basal veins abaxially ± prominent. Cymes axillary, 1--7-flowered; peduncle 0.2--3.5 cm, appressed puberulous; bracts narrowly triangular to linear, 3--8 mm. Flowers 1.2--1.5 cm in diam. Pedicel 1--3 cm, densely appressed puberulous. Sepals 4, white or yellowish, erect, ovate-oblong, 12--17 × 4--6 mm, abaxially densely puberulous, adaxially glabrous, margin abaxially velutinous, apex acute. Stamens as long as sepals; filaments densely villous; anthers oblong, 1.5--2 mm, glabrous, apex obtuse. Ovaries puberulous. Style 7--10 mm, densely villous. Achenes elliptic, ca. 3 × 1.4 mm, puberulous; persistent style to 3 cm, plumose. Fl. Oct--Nov, fr. Apr--May.