Description from Flora of China
Shrubs or trees, unarmed. Raphides absent. Leaves opposite or rarely verticillate, sometimes with domatia; stipules persistent or caducous, interpetiolar, generally triangular. Inflorescence terminal or infrequently axillary, congested-cymose to paniculate or corymbiform, several to many flowered, pedunculate, bracteate. Flowers sessile to pedicellate, bisexual, distylous. Calyx limb 4- or 5-lobed, with lobes often unequal. Corolla white, yellow, orange, or red, funnelform or salverform with tube often slender and prolonged, inside glabrous or villous, with thickened annular ring at throat; lobes 4 or 5, imbricate in bud, with margins frequently crisped. Stamens 4 or 5, inserted in corolla throat, included or exserted; filaments short or reduced; anthers dorsifixed. Ovary 2-celled, ovules numerous in each cell on axile placentas; stigmas capitate or 2-lobed, included or exserted. Fruit capsular, globose to depressed globose or dicoccous, loculicidally dehiscent into 2 valves with these valves often then splitting, woody to papery, with calyx limb persistent; seeds numerous, small, fusiform or discoid, flattened, winged; endosperm fleshy; embryo small, clavate.
This genus was formerly circumscribed broadly, to include as many as 140 species, but neotropical taxonomists now separate the species formerly treated in Rondeletia s.l. into a number of smaller genera, notably Arachnothryx Planchon and Rogiera Planchon. The cultivated species treated here belongs to Rondeletia s.s.
About 20 species: tropical America, one species widely cultivated in tropical regions; one species (introduced) in China.
(Authors: Chen Tao (陈涛); Charlotte M. Taylor)