Description from Flora of China
Lianas woody, robust, with latex. Leaves opposite, usually with petiolar glands. Inflorescences terminal or axillary cymes; bracteoles leafy, large. Flowers large, fragrant. Sepals free, bearing many basal glands inside; lobes leafy, large. Corolla white, funnelform, tube short or long, limb widely campanulate, throat not scaly, lobes overlapping to right. Stamens inserted at distal narrow portion of corolla tube; filaments arcuate, long, thickened distally; anthers sagittate, usually exserted, connivent, adherent to pistil head, cells spurred at base; disc ringlike, shallowly 5-lobed. Ovaries 2, connate, surrounded by disc; ovules numerous in each locule. Style long; pistil head fusiform. Follicles elongated, thick, hard. Seeds compressed, apex attenuate, coma silky; cotyledons leaflike or thick, radicle short.
Nine species: E and SE Asia, five species in China.