Stems climbing to several meters tall, glabrous. Petiole 2--8 cm; leaf blade ± triangular with basal lobes 1/3--1/2 as long as midvein, glabrous; sinus with parallel sides. Peduncles sometimes paired in leaf axils, not exceeding leaf; bracteoles ± overlapping each other, saccate, apex ± acute to ± obtuse. Corolla white or rarely pinkish, 4.3--6(--7.2) cm; stamens 2.3--3.3 cm; anthers (2.5--)3--5(--5.5) mm.

* Roadsides, fields, streamsides, forest margins; 100-2600 m. Anhui, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Yunnan, Zhejiang