Perennial shrubs or subshrubs; branches quadrangular, becoming terete and woody at base; hairs stellate. Leaves petiolate, opposite, simple, coarsely toothed. Inflorescence leafy, thyrse-like with sessile, usually many-flowered cymes forming dense pseudowhorls in distal axils; flowering internodes apparent. Calyx with stellate hairs, equally 10-lobed, lobes narrowly triangular, apices setiform, recurved; corolla 2-lipped, adaxial lip narrowly oblong, stiffly erect, deeply 2-lobed, abaxial lobe 3-lobed, central lobe longer and much broader than lateral ones; stamens 4, fertile, anthers with 2 fertile locules, divergent to nearly right-angles from attachment of the filament. Mericarps 3-keeled.
About 40 species, from temperate Eurasia and the Mediterranean region; 1 species naturalised in Australia.