Description from Flora of China
Lianas woody, latex white. Leaves opposite. Cymes corymbose or paniculate, dichotomous, terminal or axillary, pedunculate. Flowers small. Calyx with basal glands inside or 5-scaled. Corolla salverform, tube short, hairy inside distally, faucal scales absent, lobes overlapping to right. Stamens inserted at middle of corolla tube or at throat; filaments long, strongly intertwisted or geniculate; anthers narrowly sagittate, exserted, glutinous, connivent into a subcylindric cone, adherent to middle of pistil head, cells with an empty tail; disc 5-lobed or 5-scaled. Ovaries 2; ovules numerous in each carpel. Style filiform; pistil head thickened, apex entire or 2-cleft. Follicles 2, terete, parallel or divergent. Seeds linear or oblong, apex crowned with coma; endosperm scanty; cotyledons very narrowly oblong, flat, radicle superior.
About 50 species: SE Asia, Pacific Islands; two species in China.