Rhizomatous, strongly aromatic or foetid perennial herb, to 80-(100) cm tall, densely hirsute, with many glandular hairs, also with sessile, white, glandular scales. Petioles to 7 cm long in lower lvs, often much less in upper lvs. Lamina 5-10 × 3-6 cm, usually ovate, sometimes oblong-ovate, deeply crenate-serrate and teeth often mucronulate; base cordate; apex acute. Bracts remotely toothed or entire, very different from foliage lvs. Calyx 6-8 mm long; tube > teeth; teeth c. 3 mm long, narrow-triangular, acuminate, ± purple. Corolla 12-16 mm long, reddish purple with whitish markings on the downward curved, spathulate, lower lip; tube exserted from calyx; upper lip hooded, with dense simple and glandular hairs outside; lower lip c. 9 mm long × 8 mm across lateral lobes, > upper lip. Nutlets c. 1.5-2 mm diam., broad-obovoid or suborbicular, trigonous, smooth, almost black.