Description from Flora of China
Herbs pyramidal, perennial. Stems purplish-red when dry, erect, puberulent, angles narrowly winged, much branched. Petiole 4-7 mm; leaf blade linear-lanceolate, 1.2-3.6 cm × 3.5-9 mm, herbaceous, adaxially appressed puberulent, abaxially glabrous, midrib and veins sparsely puberulent, base cuneate-decurrent, margin remotely 1- or 2-undulate-crenate, apex obtuse. Racemes terminal, 1.5-5 cm; bracts entire, longer than calyx. Pedicel 2.5-3 mm, densely puberulent. Calyx ca. 2 mm, puberulent; scutellum ca. 0.75 mm. Corolla purple, to 1.3 cm, puberulent outside, glabrous inside; tube base saccate, throat to 3 mm wide; middle lobe of lower lip subcircular, ca. 3 mm wide, apex emarginate; lateral lobes ovate, ca. 2 mm wide. Fl. Aug-Oct, fr. Nov.
* Slopes. Guangdong, Guangxi.