Usually twining shrub, glabrous. Leaves opposite. Flowers small, in lateral paniculate cymes. Calyx 5-partite, with 5 scales within. Corolla campanulate, lobes 5, imbricate to the right in bud. Corona of 5 processes or lobes arising from about the middle of the corolla tube. Staminal corona absent. Filaments free, broad, inserted towards the base of the corolla tube; anthers sagittate, connivent over the dilated part of the style. Pollen masses granular, cohering in pairs in each cell. Pollen carriers narrow. Stigma conical. Follicles 2, terete, smooth. seeds comose.