Description from Flora of China
Herbs erect. Stems ca. 50 cm, subglabrous to sparsely retrorse pubescent or short pilose, unbranched or few branched toward apex. Petiole 0-1.5 cm, upper leaves sessile; leaf blade lanceolate, 5-13 × 1.3-3.3 cm, adaxially minutely dotted or sparsely short pilose, slightly puberulent on midrib, abaxially glabrous or sparsely short pilose, base attenuate, decurrent into petiole, apex long acuminate. Verticillasters 8-10-flowered; bracteoles ca. 1 mm, subulate, deciduous. Pedicel ca. 2 mm. Calyx obconical, ca. 5 mm, sparsely fine strigose, glabrous inside, inconspicuously 5-veined; teeth broadly ovate-triangular, ca. 2 mm, equal, apex long acuminate. Corolla ca. 1.5 cm, glabrous, villous annulate inside; tube ca. 6 mm, uniformly wide; upper lip oblong, erect, margin entire; lower lip horizontally spreading, spotted inside, middle lobe trapeziform. Ovary apex puberulent. Nutlets brown, triquetrous, oblong, truncate, puberulent, base attenuate. Fl. Apr-Aug, fr. Aug-Sep.
* Broad-leaved forests, valley forests, streamsides, shady areas, grasslands; 600-1700 m. Guangdong, Guangxi, Hunan, Jiangxi.