Vines perennial, herbaceous. Stems to 1 m, shallowly 4--6-grooved, puberulous; nodes swollen. Leaves 1- or 2-ternate; petiole 2--4 cm; leaflet blades narrowly ovate to lanceolate, 1--6 × 0.4--2 cm, papery, both surfaces very sparsely puberulous to subglabrous, base rounded to broadly cuneate, margin entire, apex acute; basal veins abaxially nearly flat. Cymes axillary, 1-flowered; peduncle 1--4 cm; bracts sessile or subsessile, broadly ovate to ovate-triangular, 1.4--3 cm. Flowers 3.6--5 cm in diam. Pedicel 3.7--8.5 cm, densely puberulous. Sepals 6, white, obovate to rhombic-obovate, 2--3 × 1--1.5 cm, abaxially densely velutinous along midvein, adaxially glabrous, margin glabrous, apex acute. Stamens if fertile 4--8 mm, glabrous; anthers oblong to linear, 2.5--3.5 mm, apex obtuse. Stamens if becoming staminodes 1--1.2 cm, glabrous, apex attenuate. Ovaries puberulous. Style ca. 3.5 mm, densely pubescent from base to middle, glabrous apically from middle; stigma dilated. Achenes broadly obovate to rhombic-orbicular, ca. 3.5 × 3 mm, puberulous; persistent style ca. 8 mm, basally spreading puberulous, apically glabrous. Fl. Apr--Jun.

* Scrub, thickets, along streams; ca. 1700 m. Guangdong, N Guangxi, Hubei, Hunan, W Jiangxi, SW Yunnan, Zhejiang.