Herbs perennial. Rhizome nodes forming woody tubers 0.5-2 cm in diam. Stems ascending, slender, flexuous, 30-60 cm, densely dusty puberulent, leafless at base. Petiole 0.5-4 cm; leaf blade lanceolate, rarely ovate, 2.5-15 × 1-4.5 cm, glabrous, yellow glandular, dusty puberulent on veins, base cuneate-decurrent, margin coarsely to double serrate, apex long acuminate to acute. Racemes terminal, slender, 10-20 cm, loose, densely glandular puberulent; verticillasters 2(-6)-flowered; peduncle 1-2.5 mm; bracts lanceolate to subulate, ca. 2 mm. Pedicel 3.5-5 mm, with 1 scalelike bracteole at base. Calyx campanulate, ca. 4 mm, glandular puberulent, obscurely 10-veined, nearly 2-lipped; teeth triangular to triangular-lanceolate, apex subulate. Corolla purple, ca. 2.1 cm; tube ca. 1.8 cm, throat ca. 4 mm wide, very finely puberulent, subglabrous inside; upper lip ca. 3 mm, lobes circular; lower lip ca. 4 mm, middle lobe slightly longer, lateral lobes ca. 2 mm wide. Anterior stamens longer, included. Fl. Sep-Nov.