Buxus is a genus of about 70 species in the family Buxaceae. They are slow-growing evergreen shrubs and small trees, growing to 2-12 m (rarely 15 m) tall. The leaves are opposite, rounded to lanceolate, and leathery; they are small in most species, typically 1.5-5 cm long and 0.3-2.5 cm broad, but up to 11 cm long and 5 cm broad in B. macrocarpa. The flowers are small and yellow-green, monoecious with both sexes present on a plant. The fruit is a small capsule 0.5-1.5 cm long (to 3 cm in B. macrocarpa), containing several small seeds.
The genus splits into three genetically distinct sections, each section in a different region, with the Eurasian species in one section, the African (except northwest Africa) and Madagascan species in the second, and the American species in the third.