Stems to 1 m, subglabrous, much branched. Petiole 0.3-1.8 cm, adaxially puberulent; leaf blade ovate-lanceolate to rhombic-lanceolate, 1.2-3.5 × 0.5-1.8 cm, papery, adaxially glabrous or subglabrous, abaxially gray, glabrous, sparsely impressed glandular, base attenuate, margin remotely acute serrate, apex acuminate to acute. Racemes numerous, 3-15 cm; bracts needlelike to linear-lanceolate, subglabrous, base broadly cuneate, apex acuminate, to 1 mm, rarely to 4 mm in fruit; rachis subglabrous. Pedicel ca. 1 mm, to 4 mm in fruit, finely puberulent. Calyx ca. 2 × 2-2.6 mm, dilated to ca. 3.5 × 4 mm in fruit, veins minutely hispid; upper lip reflexed, teeth ovate-triangular, middle tooth shorter than lateral; lower lip erect, teeth to slightly longer than upper lip. Corolla purplish, 4-5 mm, puberulent, inside obscurely hairy annulate or without hairy annulus. Nutlets gray-brown, subglobose, 1-1.6 mm in diam., loosely netted. Fl. and fr. May-Nov.