Herbs perennial, rhizomatous. Stems slender, flexuous, base prostrate, ca. 50 cm, angles and nodes hispid. Petiole ca. 1.5 cm; leaf blade triangular-cordate to hastate-triangular, ca. 3 × 2.5 cm, base cordate to truncate, margin crenate, apex obtuse. Spikes lax; verticillasters 5- or 6-flowered, widely spaced; upper floral leaves subsessile, ovate-triangular, remotely crenate, shorter than calyx tube; bracteoles ca. 1 mm, early deciduous. Pedicel less than 1 mm. Calyx obconical, ca. 6 mm, minutely hispid, conspicuously 10-veined; teeth ca. 2 × 2 mm, apical spine ca. 1 mm. Corolla reddish to purple red, ca. 1.5 cm; tube ca. 1.1 cm, puberulent, saccate; upper lip erect, oblong-ovate, ca. 4 × 3 mm; lower lip spreading, ca. 6 × 6 mm; middle lobe circular, ca. 3.5 mm in diam.; lateral lobes ovate, ca. 1.5 mm wide. Nutlets ovoid to obovoid, 1.5-3 mm in diam., brownish, smooth to tuberculate. Fl. Jul-Aug, fr. Sep, sometimes fl. and fr. Nov.