Description from Flora of China
Annuals, 3-30 cm tall, glabrous or sparsely pubescent. Primary root perpendicular, elongated or shortened; fibrous roots numerous, scattered or tufted. Stems 1 or more, erect, ascending, or procumbent-ascending, rooting from prostate nodes. Basal leaves early deciduous or few to numerous and sometimes rosulate; leaf blade obovate-spatulate to ovate-oblanceolate, 2-6 cm, membranous to papery, base cuneate and decurrent, margin coarsely and irregularly toothed or pinnately parted with 1 or 2 lobules, rarely subentire, apex entire or obscurely and sparsely toothed. Stem leaves opposite or few alternate. Racemes terminal, elongated to apically fascicled, usually 3-20-flowered, lax. Pedicel 3-12 mm. Calyx campanulate, 3-8 mm, enlarged in fruit or not; lobes ovate, almost as long as tube, apex acute. Corolla white, purple, or blue, ca. 1 cm; lower lip middle lobe smaller than lateral lobes, slightly exserted, obovate; upper lip lobes ovate-triangular. Ovary glabrous. Capsule globose. Fl. and fr. Apr-Oct.
Wet grassland, along streams, trailsides, waste fields, wet places and edge of forests, grassland on mountain slopes; 1200-3800 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Bhutan, NW India, Indonesia, Japan (Ryukyu Islands), Kashmir, Korea, Nepal, New Guinea, Philippines, Russia, Sikkim, Thailand, Vietnam].