Description from Flora of China
Herbs perennial, repent at base, with underground globose root tubers. Stems 0.5-1.5 m tall, erect to ascending, puberulent or pilose, many leafed at base. Stem leaves opposite; petiole equal to or longer than blade; leaf blade broadly lanceolate to ovate, 1.5-20 × 0.5-8.5 cm, papery, minutely hirsute, adaxially olive green, abaxially greenish, sparsely brown glandular, base cuneate to rounded, rarely shallow cordate, margin crenate, apex obtuse to acuminate. Panicles terminal and axillary, 7-20 × 3-6 cm; cymes helicoid, 11-13-flowered, pedunculate; floral leaves bractlike, ovate; bracteoles linear, 3-5 mm, slightly longer than pedicels. Calyx campanulate, ca. 2 mm, ca. 1.7 mm wide at mouth, base sparsely villous outside, sparsely red-brown glandular, 2-lipped to 2/3 its length; teeth ovate-triangular, lower 2 longer; fruiting calyx elongated, 4.5-5 mm. Corolla white or rose, with purple spots on limb, 2-7 mm; tube 3.7-5 mm, straight; upper lip 1.6-2 mm, lower lip slightly longer. Stamens and style much exserted. Nutlets brown, compressed ovoid, ca. 1 × 0.75 mm, glabrous, smooth. Fl. and fr. Aug-Dec.
Hills, forests, ravines, thickets, rice paddies, streamsides; 400-3000 m. Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Xizang, Yunnan, Zhejiang [India, Laos, Myanmar, Nepal, Thailand, Vietnam]