Vines suffruticose. Branches shallowly 4--6-grooved, subglabrous or only sparsely puberulous on nodes. Leaves ternate; petiole 2--6 cm; leaflet blades ovate-lanceolate, oblong, or ovate, 3.5--10 × 1--4.2 cm, papery, both surfaces glabrous or subglabrous or adaxially puberulous on midvein, abaxially pilose on basal veins, glaucous, base rounded to subcordate, margin entire or 1- to few dentate, apex acuminate to narrowly acuminate; basal veins abaxially ± prominent. Flowers axillary, solitary, 2--3 cm in diam. Pedicel 3--10 cm, glabrous or puberulous. Sepals 4, yellowish, erect, ovate-oblong to oblong-lanceolate, (1.5--)2.2--2.9 × 0.5--1 cm, abaxially occasionally with a narrow longitudinal wing on midvein and glabrous except for velutinous margin, adaxially densely puberulous near apex, apex acuminate. Stamens 1.4--2.2 cm; filaments apically pubescent; anthers narrowly oblong, ca. 4 mm, abaxially densely pubescent on connective, apex with a 1--1.5 mm apicula. Ovaries puberulous. Style (5--)9 mm, densely villous. Achenes narrowly obovate, 4--5 × ca. 2 mm, puberulous; persistent style ca. 2.5 cm, plumose. Fl. Jun--Jul, fr. Jul--Aug.

* Forests, forest margins, slopes, scrub; 2200--3700 m. S Gansu, W Hubei, S Shaanxi, SW to W Sichuan.