Annual ± slender herbs with simple petiolate crenate leaves, pilose. Inflorescence of long-pedunculate distant cymes arising from leaf axils. Calyx 18-20-veined, clearly oblique-gibbous, inflated at base, indistinctly bilabiate; tube without an annulus; throat straight or weakly oblique. Corolla blue, white or mauve, bilabiate, ± included in calyx. Stamens 4, didynamous, posterior pair longer than anterior. Nutlets ± globose in outline, tuberculate, with a large curved-concave ventral areole.