Description from Flora of China
Herbs annual or biennial, stoloniferous. Stems 10-30 cm tall, white villous or lanate-villous especially on young parts. Basal leaves numerous, longer than stem leaves; petiole 1-2.5 cm or more, narrowly winged, purplish green or greenish, villous; leaf blade 3-6(-14) × 1.5-2.5(-5) cm, sparsely strigose to pilose, base attenuate-decurrent, ciliate, apex obtuse to rounded. Verticillasters many flowered, basally widely spaced, apically crowded in interrupted spikes 7-12 cm; apical floral leaves bractlike, lanceolate. Pedicel short. Calyx funnelform, 5-8 mm, margin pilose; teeth triangular, to 1/2 as long as calyx. Corolla tubular, straight, basally slightly swollen, 8-10 mm, pilose, villous annulate inside; upper lip of limb straight, circular, apex emarginate; middle lobe of lower lip narrowly flabellate to obcordate, lateral lobes oblong to subelliptic. Nutlets areole to nearly 2/3 as long as adaxial side of nutlet. Fl. Mar-Jul, fr. May-Nov.
Streamsides, roadsides, wet grassy slopes, wet areas in bamboo forests; 400-2300 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Qinghai, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Korea]