Deciduous or evergreen trees. Leaves alternate, simple, serrate, lobed or pinnatifid, rarely entire. Male and female flowers in separate inflorescences. Male flowers borne in pendent catkins; perianth 4-7-lobed; stamens (4-)6(-12). Female flowers solitary or borne in spikes; ovary usually 3-celled, surrounded by an involucre of imbricated bracts which become the cup of the fruit. Fruit a spherical to oblong nut (an acorn), surrounded at the base or almost enclosed by a cup-like involucre.
Derivation of name: an ancient Latin name. Worldwide: c. 400 species in mainly Northern temperate regions, also in the subtropics and mountains of the tropics, extending south to SE Asia and the Andes of Colombia. Zimbabwe: 8 cultivated taxa. |