Twining rarely erect shrubs. Leaves opposite, cordate. Flowers in umbelloid or paniculate cymes. Calyx 5-lobed, lobes ovate-oblong, obtuse. Corolla purple, subcampanulate, puberulous outside, lobes 5, imbricate in bud . Corona single, consisting of 5 flat erect segments, attached to the staminal column. Staminal column arising from or near the base of the corolla. Anthers with connectives produced into membranous appendages ± incumbent on style top. Pollinia 1 in each loculus, erect, without a pellucid margin. Stigma (style apex) depressed, convex, conical or beaked. Follicles with thick pericarp, usually lanceolate, smooth, wrinkled or winged. Seeds comose.