Description from Flora of China
Vines, without tendrils. Leaves opposite, 1-pinnately compound; leaflets 3-5(-7), entire. Inflorescences racemose, terminal. Calyx campanulate, apex subtruncate; teeth 5, short acute. Corolla white, tube very long, narrowly cylindric, slightly bilabiate; lobes ovate-rounded, subequal, patent. Stamens 4 and didynamous or 5, inserted high in corolla tube; anthers divergent, ellipsoid, longitudinally dehiscing, apex with a caudate appendage. Disc cushionlike. Ovary short terete; ovules in several rows. Style filiform; stigma compressed. Capsule dehiscing septicidally, long ellipsoid, compressed, with a persistent calyx. Seeds numerous, compressed, rounded, transparent winged.
About three to five species: Cambodia, China, NE India, Indonesia, Malaysia, Myanmar, Philippines, Thailand; two species in China.