Twining, glabrous herbs or undershrubs. Leaves opposite, ovate-lanceolate to linear-lanceolate. Flowers in lax racemoid or umbelloid cymes, solitary at nodes. Calyx lobes lanceolate, acute, glandular inside. Corolla shallowly campanulate to almost rotate, glabrous outside, lobes about as long as the tube, imbricate in bud. Corona in 2 series, the outer a densely pubescent annulus at the base of the corolla tube, the inner of 5 ovate-lanceolate segments attached to the staminal column and longer than anthers. Stamens inserted at the base of the corolla tube, filaments short, connate, anthers tipped by membranous appendages. Pollinia solitary in each anther loculus, pendulous, without a pellucid margin. Style apex truncate or convex. Follicles often solitary, oblong and obtuse or lanceolate and acute. Seeds comose.