Annual or perennial, taprooted or rhizomatous herbs or subshrubs, unarmed, usually hairy. Lvs usually opposite, rarely in whorls of 3 or alternate, usually toothed or lobed. Infl. usually of 1 or more terminal spikes, these often corymbosely or paniculately arranged; fls sessile or subsessile, usually rather small, bracteate. Calyx tubular, 5-ribbed and unequally 5-toothed, ± accrescent. Corolla salverform; tube straight or curved, usually > calyx; limb 5-lobed and ± 2-lipped, the lobes obtuse or emarginate. Stamens 4, didynamous, included. Style included. Ovary 4-celled; ovules 1 to each cell. Fr. dry, separating into 4 nutlets.