Description from Flora of China
Herbs ascending, sometimes stoloniferous. Stems 20-30 cm tall, pubescent, branched apically. Petiole narrowly winged, 1-3 cm; leaf blade obovate to oblong-obovate, rarely triangular-obovate, 3-4(-10) × 2(-5) cm, subglabrous, pubescent along midrib, base cuneate to decurrent, margin coarsely dentate to irregularly crenate, sparsely ciliate, apex obtuse to subrounded. Verticillasters 12- or more flowered, in terminal spikes 5-12 cm; apical floral leaves bractlike, ovate to ovate-lanceolate, margin dentate to entire, smallest ca. 8 × 4 mm. Calyx campanulate, 3.5-4.5 × 3-3.5 mm; teeth ovate-triangular, to 1/2 as long as calyx, ciliate, sparsely villous. Corolla white, tubular, straight, slightly bent, 6-8 mm, tube glabrous, limb ± villous, villous annulate inside; upper lip semicircular, 2-lobed; lower lip projected, with middle lobe narrowly cordate, ca. 2 × 1.5 mm, apex emarginate; lateral lobes oblong, ca. 1.5 × 1 mm. Nutlets areole to 2/3 length of adaxial side of nutlet. Fl. and fr. Mar-Jun.
Wet grasslands. Fujian, Guangdong, Jiangxi, Taiwan [Japan (Ryukyu Islands), Vietnam].