Annual-perennial herbs to shrubs of varying habit, mat forming - erect subshrubs. Leaves simple, basal or cauline or both, basal often forming a rosette, cauline opposite rarely alternate. Inflorescence various: racemes, cymes, verticillate clusters or solitary. Flowers variously coloured: blue, purple, violet, pink, white, yellow, 4-8 (-10) merous, bisexual, regular actino-zygomorphic. Calyx also variable with 4-8 (-10) united, or free or semiunited sepals, or calyx divided from one side. Corolla 4-8 (-10) merous, provided with or without appendages or subsidiary lobes, fimbriate or fimbriae absent, nectaries either epipetalous or at base of ovary or absent. Ovary superior, unilocular, with parietal placentation. Fruit a 2 valved dehiscent capsule. Seeds few to many.