Herbs twining, to 5 m. Stems pubescent along 1 side; axillary glands villous. Petiole 1.5-2 cm, slightly flattened, pubescent; leaf blade elliptic, ca. 9 × 5.3 cm, thin papery, pubescent, glabrescent, base rounded or truncate, margin ciliate, apex acute; lateral veins 5 or 6 pairs, flattened adaxially, elevated abaxially. Inflorescences umbel-like; peduncle to 6 cm, puberulent; cymules solitary or 2 close together. Pedicel ca. 8 mm, glabrescent. Sepals linear-lanceolate, ca. 2.5 × 0.7 mm, villous, ciliate. Corolla white, rotate, ca. 7 mm in diam., glabrous; tube ca. 1 mm; lobes elliptic, ca. 3 × 2.5 mm. Corona lobes ovate, apex acute. Anther appendages ovate; pollinia subglobose, horizontal. Stigma head discoid. Fl. May-Aug.

* Montane forests; ca. 2100 m. Sichuan, Yunnan.