Description from Flora of China
Lianas. Inflorescences umbel-like clusters of cymules; peduncle and pedicels long and slender. Sepals overlapping, with 5 basal glands. Corolla rotate to shallowly bowl-shaped, deeply 5-divided; lobes overlapping to right. Corona lobes 5, ± spreading, thick fleshy, adnate to stamens, outer angle obtuse or rectangular, interior angle produced into an acute tooth incumbent to anthers. Anthers with membranous apical appendages; pollinia 2 per pollinarium, oblong, erect. Stigma head umbonate or thick conical. Follicles widely divergent, thick, finely longitudinally ribbed or corrugate, not winged [or winged]. Seeds comose.
About 12 species: southern Asia, Africa; four species in China.