Large twining shrubs or trees with milky latex. Leaves opposite elliptic, oblong to lanceolate, glabrous minutely dotted. Inflorescence of axillary and dischotomously branched peduncled cyme or fasicles with white flowers. Calyx 5-partite, glandular or eglandular inside with narrow acute, ovate-lanceolate lobes. Corolla hypocrateriform or somewhat rotate with naked throat, tube cylindrical, lobes almost twice the length of the tube, broad, strongly overlapping to the right in bud. Stamens partly exerted, inserted at the top of corolla tube, filaments shorts anthers connivent and adhering to stigma; connective with a large dorsal gland. Disc 5-lobed, annular or cupular. Carpels 2; ovules many; style filiform, pubescent, with somewhat annulate thick stigma. Fruit oblong, acuminate, splitting from below into two distinct follicles along the ventral suture. Seeds biseriate, ovate compressed, acuminate, comose at the apex.