Perennial herbs, usually with creeping non-flowering stems and ascending flowering stems. Lvs simple, reniform to ± orbicular, toothed. Verticels 2-5-flowered, axillary, secund. Bracts resembling ordinary lvs. Calyx tubular or tubular-campanulate, 15-veined, not gibbous at base, somewhat 2-lipped, with an upper lip of 3 teeth and a lower of 2. Corolla 2-lipped; tube straight, widened towards apex; upper lip flat, subentire or with 2 teeth; lower lip of 3 teeth, hairy towards base. Stamens lying below upper lip; anther cells at right angles to each other. Style gynobasic, its branches equal. Nutlets smooth, ± obovoid.