Dwarf shrubs or perennial herbs, trailing or erect, evergreen or deciduous. Leaves opposite; petiole prominent. Flowers solitary in leaf-axils, pedicellate; sepals linear, lacking basal glands but with 2 marginal glands; corolla usually blue; corolla-tube cylindric, hairy or thickened at throat; corolla-lobes broad, twisted, spreading; stamens enclosed in corolla-tube, inserted c. halfway along tube on short filaments, anthers hairy on back, hooded, coherent around the style head; nectary scales 2, alternating with the ovaries; carpels free except at style; style filiform, style head with a circular tuft of hairs around a thickened rim. Fruit usually of 2 erect or divergent cylindric follicles; seeds lacking wings or hairs.
7 species from Europe and Africa; 1 (possibly 2) species naturalised in Australia.