Oak

oak, (genus Quercus), genus of about 450 species of ornamental and timber trees and shrubs in the beech family (Fagaceae), distributed throughout the north temperate zone and at high altitudes in the tropics. Acorns provide food for small game animals and are used to fatten swine and poultry; the acorns of some species can be made into a flour for human consumption. Red- and white-oak lumber is used in construction, flooring, furniture, millwork, cooperage, and the production of crossties, structural timbers, and mine props.

Many plants commonly called “oak” are not Quercus species—e.g., African oak, Australian oak, bull oak, Jerusalem oak, poison oak, river oak, she-oak, silky oak, tanbark oak, Tasmanian oak, and tulip oak.