Vines woody. Branches fistulose, shallowly 10--18-grooved, densely furfuraceous at nodes, elsewhere glabrous. Leaves pinnate, 7-foliolate; petiole ca. 7 cm, glabrous, base with stipulelike projections ca. 8 mm and abaxially densely furfuraceous; leaflet blades ovate, 4--6 × 2.2--4 cm, papery, both surfaces glabrous, base rounded, margin entire, apex acuminate; basal veins 5, abaxially nearly flat, adaxially inconspicuous. Cymes axillary, 3-flowered; peduncle 7.8--14 cm, glabrous; bracts caducous. Flowers ca. 5 cm in diam.; pedicel robust, 6--11 cm, glabrous. Sepals 4, white, spreading, oblong-lanceolate, 2.7--3.2 × 0.6--0.9 cm, abaxially densely fulvous furfuraceous-velutinous, adaxially glabrous, margin whitish velutinous, apex acute. Stamens unequal, glabrous; outer stamens ca. 2 cm, filaments linear, ca. 1.8 cm, anthers oblong, ca. 1.5 mm, connective projections subulate, 0.5--0.7 mm; inner stamens 0.7--1.1 cm, filaments 3.6--6.5 mm, anthers narrowly oblong, ca. 2 mm, connective projections ca. 1 mm. Ovaries densely pubescent; style ca. 8 mm, densely villous. Fl. Sep.

* Mixed forests; ca. 1500 m. SE Yunnan (Xichou Xian).