An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta 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 has the largest number of oak species, with approximately 160 species in Mexico, of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species.
Quercus petraea, commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an unofficial emblem in Wales and Cornwall.
Quercus macrocarpa, the bur oak or burr oak, is a species of oak tree native to eastern North America. It is in the white oak section, Quercus sect. Quercus, and is also called mossycup oak, mossycup white oak, blue oak, or scrub oak. The acorns are the largest of any North American oak, and are important food for wildlife.
Quercus tomentella, the island oak, island live oak, or Channel Island oak, is an oak in the section Protobalanus. It is native to six islands: five of the Channel Islands of California and Guadalupe Island, part of Baja California.
Quercus pubescens, commonly known as the downy oak, pubescent oak or Italian oak, is a species of white oak native to southern Europe and southwest Asia. It is found from northern Spain (Pyrenees) and France in the West to Turkey and the Caucasus in the East.
Quercus lyrata, the overcup oak, is an oak in the white oak group. The common name, overcup oak, refers to its acorns that are mostly enclosed within the acorn cup. It is native to lowland wetlands in the eastern and south-central United States, in all the coastal states from New Jersey to Texas, inland as far as Oklahoma, Missouri, and Illinois. There are historical reports of it growing in Iowa, but the species appears to have been extirpated there. It is a slow-growing tree that often takes 25 to 30 years to mature. It has an estimated lifespan of 400 years.
Quercus chrysolepis, commonly termed canyon live oak, canyon oak, golden cup oak or maul oak, is a North American species of evergreen oak that is found in Mexico and in the western United States, notably in the California Coast Ranges. This tree is often found near creeks and drainage swales growing in moist cool microhabitats. Its leaves are a glossy dark green on the upper surface with prominent spines; a further identification arises from the leaves of canyon live oak being geometrically flat.
Quercus prinoides, commonly known as dwarf chinkapin oak, dwarf chinquapin oak, dwarf chestnut oak or scrub chestnut oak, is a shrubby, clone-forming oak native to central-eastern North America.
Quercus alnifolia, commonly known as the golden oak, is an evergreen oak species of Cyprus. Its common English name refers to the golden coloured lower surface of its leaves. Quercus alnifolia belongs to the endemic flora of the island and it is confined to the igneous geological complex of the Troodos Mountains. In February 2006, the parliament of Cyprus selected the golden oak to be the country's national tree.
Quercus pagoda, the cherrybark oak, is one of the most highly valued red oaks in the southern United States. It is larger and better formed than southern red oak and commonly grows on more moist sites. Its strong wood and straight form make it an excellent timber tree. Many wildlife species use its acorns as food, and cherrybark oak makes a fine shade tree. Cherrybark oak was formerly considered to be a subspecies of southern red oak, Quercus falcata, subsp pagodifolia.
Quercus palmeri is a species of oak known by the common name Palmer oak, or Palmer's oak. It is native to California, Baja California, Southern Nevada, and in Arizona through the transition zone to the eastern Mogollon Rim, where it grows in canyons, mountain slopes, washes, and other dry habitats.
Quercus turbinella is a North American species of oak known by the common names shrub oak, turbinella oak, shrub live oak, and gray oak. It is native to Arizona, California, New Mexico, Utah, Colorado, and Nevada in the western United States. It also occurs in northern Mexico.
Quercus ithaburensis, the Mount Tabor oak, is a tree in the beech family Fagaceae. It is found from southeastern Italy to the Palestine region. It is the national tree of Jordan. Two subspecies are accepted, Quercus ithaburensis subsp. ithaburensis and Quercus ithaburensis subsp. macrolepis. Together with Quercus brantii, it forms a clade of distinct, closely related species within the oak section Cerris.
Quercus pungens, commonly known as the sandpaper oak or scrub oak, is a North American species evergreen or sub-evergreen shrub or small tree in the white oak group. There is one recognised variety, Quercus pungens var. vaseyana, the Vasey shin oak. Sandpaper oak hybridizes with gray oak in the Guadalupe Mountains of New Mexico and Texas.
Quercus mohriana, commonly known as the Mohr oak, shin oak or scrub oak, is a North American evergreen shrub or small tree in the white oak group and is native to the south-central United States and north-central Mexico. The species epithet mohriana honors the pharmacist and botanist Charles Mohr of Alabama.
Quercus grisea, commonly known as the gray oak, shin oak or scrub oak, is a North American species deciduous or evergreen shrub or medium-sized tree in the white oak group. It is native to the mountains of the southwestern United States and northern Mexico. It hybridises with four other oak species where the ranges overlap, the Arizona white oak (Q. arizonica), the Gambel oak (Q. gambelii), the Mohr oak (Q. mohriana) and the sandpaper oak (Q. pungens).
Quercus geminata, commonly called sand live oak, is an evergreen oak tree native to the coastal regions of the subtropical southeastern United States, along the Atlantic Coast from southern Florida northward to southeastern Virginia and along the Gulf Coast westward to southern Mississippi, on seacoast dunes and on white sands in evergreen oak scrubs.
Quercus hypoleucoides, the silverleaf oak or the whiteleaf oak is a North American species of oak tree or shrub. It grows in the southwestern United States and northern Mexico.
Quercus pyrenaica, also known as Pyrenean oak, or Spanish oak is a tree native to southwestern Europe and northwestern North Africa. Despite its common name, it is rarely found in the Pyrenees Mountains and is more abundant in northern Portugal and north and northwestern Spain.
Quercus mulleri is a rare Mexican species of oak. It has been found only in a small area of the Sierra de Miahuatlán, a sub-range of the Sierra Madre del Sur in southern Oaxaca state.
