Description from Flora of China
Lianas woody, latex white. Leaves opposite. Cymes axillary, long pendunculate, with 2 or 3 monochasial branches. Calyx deeply divided, with basal glands inside. Corolla subcampanulate, tube cylindric, slightly inflated distally, throat without scales, lobes overlapping to right. Stamens inserted at middle of corolla tube; filaments short; anthers sagittate, included, adherent to pistil head at middle, cells with an empty tail; disc ringlike, as long as ovary, apex entire or 5-lobed. Ovaries 2, free. Style filiform; pistil head cylindric, apex long pubescent. Follicles 2, ellipsoid to narrowly so, connate. Seeds ovate, apex comose.
One species: China, Laos, Myanmar, Thailand, Vietnam.