Description from
Flora of China
Shrubs or lianas. Cymes extra-axillary or terminal, lax, irregularly forked. Calyx glands 5, minute. Corolla rotate; tube short, overlapping to right. Corona lobes 5, slender, inflexed, adnate to filaments. Stamens inserted at corolla base; filaments distinct, threadlike, alternate with minute teeth; anthers connivent, adnate to stigma head, appendages membranous; pollen tetrads in solitary masses in each anther cell, pollen carriers erect; retinaculum minute, dilated at base. Stigma head convex, angular. Follicles paired, divaricate, cylindric, ovoid, or beaked.
About five species: SE Asia, one in China.