Description from Flora of China
Shrubs or small trees to 5 m. Branchlets glabrous, puberulent, or pubescent. Petiole 1-3 cm; leaf blade ovate, ovate-orbicular, to reniform, slightly broader than long or slightly narrower than long, 2.5-10(-14) × 2.5-8(-15) cm, glabrous or pubescent, villous to glabrescent, base subcordate or truncate to broadly cuneate, apex abruptly acute to long acuminate. Panicles erect, lateral, congested or lax, 4-16(-20) × 3-8(-10) cm. Pedicel 0-3 mm, glabrous or pubescent. Calyx 2-3 mm. Corolla purple, lilac, or sometimes white; tube subcylindric, 0.6-1.7(-2.2) cm; lobes ovate-orbicular to oblong or obovate-orbicular, 4-8(-10) mm, spreading. Anthers yellow, inserted 0-4 mm from mouth of corolla tube. Capsule obovate-elliptic, ovate, to oblong-lanceolate, 0.7-1.5(-2) cm, smooth.
Woods, thickets, valleys, along streams, roadsides, gravely mountains; 100-2600 m. Gansu, Hebei, Henan, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, NW Sichuan; widely cultivated in several other provinces [Korea]