Branched to nearly unbranched shrubs, treelets, or trees 1-10 m high. Leaves sessile or petiolate, 3-60 cm long; camptodromous-veined. Inflorescences terminal, cymose or sometimes a thyrse; bracts and bracteoles leaf-like or scale-like towards inflorescence apex. Flowers pedicellate, 5-merous, slightly zygomorphic; calyx fused for ca. 1/2 of length, leathery to thin-leathery, campanulate, lobes of various shapes, with dorsally thickened glandular area, not keeled or winged, apex of various shapes; corolla bud apex rounded; corolla fused for ca. 3/4 of length, fleshy in most species, funnel-shaped, tubular, or salver-shaped; androecium zygomorphic with stamens and style bent towards bottom of corolla mouth; stamens inserted in corolla tube, of unequal length, base of filaments without appendages or a corona, anthers linear; pollen in monads; pistil with nectary disk around base, stigma bilamellate. Fruit a capsule, with calyx persistent and corolla deciduous; seeds angular, rounded, or flat, testa pattern with concave and/or dome-like cells.
Andes: present Atlantic forest of SE Brazil: present Dominican Republic: present Greater Antilles: present Guyana, Republic of: present Jamaica: present Mt. Ayanganna: present Southern America:, Bolivia (Bolivia ‒ present); Colombia (Colombia ‒ present); Costa Rica (Costa Rica ‒ present); Cuba (Cuba ‒ present); Ecuador (Ecuador ‒ present); Panamá (Panamá ‒ present); Peru (Peru ‒ present); Venezuela (Venezuela ‒ present) Venezuelan tepuis: present tepuis of Venezuela and Guyana: present
A neotropical genus of about 110 species, from Costa Rica, Panama, the Greater Antilles of the Caribbean (Jamaica, Cuba, and the Dominican Republic), the Andes (Venezuela, Colombia, Ecuador, Peru, and Bolivia), the tepuis of Venezuela and Guyana and the Atlantic forest of SE Brazil; 1 species in Guyana (Mt. Ayanganna); on the Venezuelan tepuis an additional 5 species occur.