Twining shrub. Rootstock woody. Leaves opposite. Flowers in subsessile lateral cymes. Calyx 5-partite, glandular inside the base. Corolla greenish purple, rotate, lobes valvate, glabrous. Corona of 5 fleshy lobes from below the sinus. Staminal corona absent. Filaments free, anther tips connivent over style apex. Pollen granular, usually cohering in masses in pairs in each cell. Pollen carriers obconical. Style apex 5-gonous, flat on the top. Follicle terete, slender, smooth.