Perennial succulent herbs, rarely subshrubs. Stem erect, frequently rhizomatous, or plants tuberous and either acaulescent or shortly stemmed, rarely lianoid or climbing with adventitious roots, or stoloniferous. Leaves simple, rarely palmately compound, alternate or all basal; blade often oblique and asymmetric, rarely symmetric, margin often irregularly serrate and divided, occasionally entire, venation usually palmate; petiole long, weak; stipules membranous, usually deciduous. Flowers unisexual, plants monoecious, rarely dioecious, (1 or) 2-4 to several, rarely numerous, in dichotomous cymes, sometimes in panicle, with pedicels and bracts. Staminate flower: tepals 2 or 4 and decussate, usually outer ones larger, inner ones smaller; stamens usually numerous; filaments free or connate at base; anthers 2-celled, apical or lateral; connectives extended at apex, sometimes apiculate. Pistillate flower: tepals 2-5(-10) ; pistil composed of 2-5(-7) carpels; ovary inferior, 1-3(-7) -loculed; placentae axile or parietal; styles 2 or 3(or more), free or fused at base, forked once or more; stigma turgid, spirally twisted-tortuous or U-shaped, capitate or reniform, setose-papillose. Capsule dry, sometimes berrylike, unequally or subequally 3-winged, rarely wingless and 3- or 4-horned; seeds very numerous, pale brown, oblong, minute, testa reticulate.
More than 1400 species: widely distributed in the tropical and subtropical regions of the world, with ca. 150 species in Africa, more than 600 species in Central and South America, and more than 600 species in Asia; 173 species (141 endemic) in China.[1]
The Genus Begonia is further organized into finer groupings including: