Description from Flora of China
Herbs perennial, stoloniferous. Stems erect, 30-70 cm tall, basally glabrous or subglabrous, apically glandular pubescent or glabrous. Petiole 1-3 cm, subglabrous; blade ovate to ovate-oblong, 3-10 cm, subglabrous or very sparsely puberulent, base rounded, broadly cuneate to cuneate, margin double crenate-serrate, apex acute to short acuminate. Spikes on apical parts of stem and branches, 3-7 cm, densely glandular pubescent; verticillasters close together, 2-flowered; bracts lanceolate. Pedicel 1-2 mm, densely glandular villous. Calyx campanulate, 2.8-4 × 2.2 mm; teeth straight, subequal, less than 1/2 as long as calyx tube, upper 3 ovate-triangular, lower 2 triangular. Corolla white, reddish, or purplish, 6.5-7.5 mm, tube ca. 3 mm; middle lobe circular, lateral lobes ovate-triangular, obtuse. Ovary apically bullate, hairy. Style as long as stamens. Nutlets yellow-brown, oblate, ca. 1.3 mm. Fl. Jun-Nov (Jun-Sep in the Chang Jiang basin; Jun-Nov in Guangdong and S Yunnan).
Moist forests, ravines, thickets on slopes; 100-2500 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [India, Indonesia, Japan, Korea, Myanmar, Philippines]