Perennial, erect or procumbent herbs with milky latex. Leaves opposite without glands. Flowers solitary axillary. Calyx lobes more or less equal, eglandular inside. Corolla infundibuliform, blue, purple or white, corona absent. Stamens 5, included, anthers hairy at the tip, broadly oblong with an enlarged connective. Carpels 2, free, with numerous ovules in each carpel, nectaries 2, alternating with the carpel. Style filiform; stigma capitate, hairy. Follicles 2, terete, with cylindric to subcylindrical seeds.