Erect shrub to nearly 3 m high with stems densely puberulent at first. Petioles to c. 6 cm long, purplish. Lamina 6-17 × 2.5-8 cm, ovate or elliptic-ovate, puberulent, densely so on veins above and generally below, dotted with red or dark red glands on both sides (more obvious when dry), irregularly dentate-serrate; base narrow-cuneate; apex acute. Infl. a loose, erect panicle to c. 30 cm tall, purple, with 2-3 pairs of branches; lower bracts mostly c. 1 cm long, broad-ovate or oblong, dotted with red glands. Pedicels slender, > calyx, almost glabrous or glandular-puberulent. Calyx teeth 3-5 mm long, accrescent, ciliate, dotted with glands; upper tooth ovate, obtuse; lower 4 teeth lanceolate-subulate. Corolla purplish, violet or bluish violet; tube (1)-1.3-1.5 cm long, narrow, glandular-puberulent outside, gradually widening to apex; upper lip ± erect, c. 5 mm long, with 2 rounded lobes; lower lip boat-shaped, horizontal to deflexed. Stamens free at base, the longer lower pair c. 1.5 cm long, becoming exserted. Style 2-2.5 cm long, long-exserted. Nutlets c. 2 mm long, broad-oblong, brown.