Description from Flora of China
Herbs 60-100(-120) cm tall, erect to climbing. Stems minutely puberulent, soon glabrous; internodes 0.5-8(-12) cm. Petiole 0.3-2.3 cm; leaf blade oblong, triangular-ovate, or ovate, sometimes deeply 3-lobed, 1-5 X 0.8-2 cm, papery, base cuneate, subrounded, or subcordate, margin serrate, apex short acuminate to acute. Cyme usually 1-flowered; bracts awl-shaped. Open flowers: Calyx 10-veined; teeth 5, 5-8 X 1 mm, margin entire, ciliate, apex acuminate. Corolla bluish purple to purple, 1.4-1.8 cm, tube ca. 12 X 2 mm; lower lip wedge-shaped to obovate-triangular, middle lobe 8-5.5 mm, lateral lobes 3-5 mm; upper lip broadly elliptic, ca. 4 X 3 mm. Cleistogamous flowers: Calyx ca. 3 mm. Corolla ca. 1.5 mm, lower lip with middle lobe ca. 0.5 mm and lateral lobes ca. 0.2 mm; upper lip ovate to subrounded, ca. 0.2 mm. Nutlets ca. 5 X 2.8 mm.
* 600-1900 m. Fujian, Guangdong, Guangxi, Hainan, Hunan, Jiangxi, Sichuan, NE Yunnan