Vines woody. Branches shallowly longitudinally 10-grooved. Leaves ternate; petiole 2--11 cm, sparsely puberulous, glabrescent; leaflet blades ovate, elliptic-ovate, or narrowly ovate, 7.5--12(--14) × 1.5--5(--9.5) cm, subleathery to papery, both surfaces sparsely puberulous, glabrescent, adaxially smooth or rarely finely rugose, base rounded, subcordate, or broadly cuneate, margin entire, apex acuminate to acute; basal veins abaxially prominent. Cymes axillary or terminal, usually paniclelike and many flowered, rarely 1-flowered; peduncle 2.6--7.5 cm, sparsely puberulous; bracts subulate, 3.5--6 mm. Flowers 1.6--2.5 cm in diam. Pedicel 0.6--1.6 cm, puberulous or rarely glabrous. Sepals 4, white, spreading, narrowly oblong to lanceolate, 8--13 × 2.2--4 mm, abaxially glabrous, adaxially glabrous, margin abaxially velutinous, apex ± obtuse. Stamens 5--9.5 mm, glabrous; anthers narrowly oblong to linear, 3--5.5 mm, apex minutely apiculate. Ovaries puberulous. Style 5--9 mm, densely villous. Achenes falcate-lanceolate, 5--7 × 1.8--2 mm, pubescent; persistent style 2--4 cm, yellow plumose. Fl. Jun--Aug, fr. Aug--Oct.

Forests, forest margins, scrub, slopes, along streams; near sea level to 1800 m. Fujian, Guangdong, Guangxi, S Guizhou, Hainan, Hubei, S Hunan, Jiangxi, Sichuan, Taiwan, S Yunnan, S Zhejiang [Japan (including Ryukyu Islands), Laos, Myanmar, Philippines, Vietnam].