Terrestrial or epiphytic, caulescent, clambering or erect, coarse herbs or shrubs, without modified stems. Stems rarely branched. Leaves opposite, usually equal in a pair, venation pinnate, foliar nectaries absent. Flowers solitary or in fasciculate few-flowered, epedunculate inflorescences; bracteoles small; pedicellate. Calyx lobes 5, nearly free, ovate to cordate at base; corolla yellow or red, tubular, limb of 5 lobes; stamens included, filaments basally connate, anthers coherent or becoming free, dehiscing by longitudinal slits, thecae parallel; staminode small; disc a single dorsal, large, sometimes 2-lobed gland; ovary superior, stigma stomatomorphic to 2-lobed. Fruit a fleshy, green capsule, loculicidally dehiscent, 2-valved, valves opening slightly.
C America present, Guianas present, Hispaniola present, Northern America, Southern America: Bolivia (Bolivia present), Suriname present, northern S America present
A genus of about 60 species mainly in C America and northern S America, from Mexico to Bolivia and Suriname, as well as Hispaniola; 2 species in the Guianas.