Erect annual or perennial herbs. Lvs opposite, with milky latex. Fls axillary, solitary or in pairs, 5-merous. Calyx small, deeply lobed, without basal glands. Corolla salverform; tube narrow, throat closed by hairs; limb patent, twisted anticlockwise in bud. Filaments very short; anthers oblong, connivent into cone around stigma, the base shortly sagittate and connective not spreading. Disc consisting of 2 glands alternating with ovary. Carpels 2; ovules many; style uniformly slender; stigma with thin transparent collar at base. Follicle cylindric, erect or partly so. Seeds 15-30 per follicle, tuberculate; coma 0.