An oak is a tree or shrub in the genus Quercus; Latin "oak tree" of the beech family, Fagaceae. There are approximately 600 extant species of oaks.
The common name "oak" also appears in the names of species in related genera, notably Lithocarpus (stone oaks), as well as in those of unrelated species such as Grevillea robusta (silky oaks) and the Casuarinaceae (she-oaks).
The genus Quercus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America contains the largest number of oak species, with approximately 90 occurring in the United States, while Mexico has 160 species of which 109 are endemic.
This page uses material from the Wikipedia article "Oak", which is released under the Creative Commons Attribution-Share-Alike License 3.0.