Perennial herb with stems ascending to c. 60 cm tall. Lower lvs shortly petiolate, the upper sessile. Lamina 2.5-12 × 1.5-8 cm, broad-ovate, or broad-elliptic to suborbicular, mostly glabrous, membranous, crenate, sometimes basal teeth again divided; apex usually rounded. Upper lvs wider than long, amplexicaul, sometimes hairy. Fls solitary in axils of upper lvs. Pedicels 1-4 cm long at anthesis, slender, usually densely glandular-hairy. Calyx 1.2-1.7 cm long, tubular-campanulate, accrescent and becoming inflated; teeth glandular-hairy, much < tube, the uppermost longer than lower. Corolla 3-4.5 cm long, strongly irregular, yellow with red dots in throat on bearded lower lip; upper lip with pouch ± closing throat. Capsule c. 10 mm long, oblong. Seeds reticulate.