Plants perennial or annual, erect trailing or decumbent, glabrous, pubescent, or hirsute. Leaves simple, alternate or forming rosettes at the base. Inflorescence 1-many flowered, with racemes or spikes. Flowers blue to purple or white. Sepals 5, with or without reflexed appendages between lobes; calyx tube adnate to the ovary, segments 5-lobed. Corolla campanulate, funnel-shaped or tubular. Stamens 5, free, filaments dilated at the base. Ovary 3-locular; style cylindrical; stigmas 3. Fruit a capsule, elongated to ovoid, obovoid or round, with membran¬ous walls; dehiscence by irregular pores at the bases or the sides. Seeds minute, numerous.