Description from Flora of China
Shrubs erect, canescent. Leaves opposite, broad, subsessile. Cymes extra-axillary or terminal, umbel-like, long pedunculate. Calyx with basal glands. Corolla bowl-shaped to subrotate, divided to middle; lobes valvate or overlapping to right. Corona lobes 5, adnate to gynostegium, fleshy, laterally compressed, apex with a tubercle on each side, with abaxial, basal, revolute spur. Filaments connate; anther appendages incurved; pollinia 2 per pollinarium, oblong, pendulous. Styles long; stigma head slightly convex. Follicles ovoid, subglobose, or oblong-lanceolate, mesocarp inflated.
Three species: northern Africa, Arabia, and tropical Asia; two species in China.