Lianas or twining herbs. Leaves linear to lanceolate, usually with minute, pale, adaxial dots. Inflorescences extra-axillary, with 1 to few, umbel-like, rarely elongated cymules. Sepals valvate, often with 5 basal glands. Corolla urceolate or campanulate, lobes valvate. Corona inserted at base of gynostegium, ringlike, shallowly 5-cleft or toothed. Filaments connate into a short tube; anther appendages incurved; pollinia 2 per pollinarium, oblong, pendulous. Stigma head discoid. Follicles usually 1, narrowly lanceolate in outline.

About 13 species: all endemic to China.