An oak is a hardwood tree or shrub in the genus Quercus of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisphere; it includes some 500 species, both deciduous and evergreen. Fossil oaks date back to the Middle Eocene. Molecular phylogeny shows that the genus is divided into Old World and New World clades, but many oak species hybridise freely, making the genus's history difficult to resolve.
Quercus rubra, the northern red oak, is an oak tree in the red oak group. It is a native of North America, in the eastern and central United States and southeast and south-central Canada. It has been introduced to small areas in Western Europe, where it can frequently be seen cultivated in gardens and parks. It prefers good soil that is slightly acidic. Often simply called red oak, northern red oak is so named to distinguish it from southern red oak (Q. falcata), also known as the Spanish oak. Northern red oak is sometimes called champion oak.
Quercus muehlenbergii, the chinquapinoak, is a deciduous species of tree in the white oak group. The species was often called Quercus acuminata in older literature. Quercus muehlenbergii is native to eastern and central North America. It ranges from Vermont to Minnesota, south to the Florida panhandle, and west to New Mexico in the United States. In Canada it is only found in southern Ontario, and in Mexico it ranges from Coahuila south to Hidalgo.
Quercus velutina, the black oak, is a species of oak in the red oak group, native and widespread in eastern and central North America. It is sometimes called the eastern black oak.
Quercus virginiana, also known as the southern live oak, is an evergreen oak tree endemic to the Southeastern United States. Though many other species are loosely called live oak, the southern live oak is particularly iconic of the Old South. Many very large and old specimens of live oak can be found today in the Deep South region of the United States.
Quercus laevis, the turkey oak, is a member of the red oak group of oaks. It is native to the southeastern United States. The name turkey oak derives from the resemblance of the leaves to a turkey's foot. A Turkish and southern European species Quercus cerris is also commonly referred to as Turkey oak, so Quercus laevis is sometimes referred to as American turkey oak to distinguish it from the European species.
Quercus agrifolia, the California live oak, or coast live oak, is an evergreen live oak native to the California Floristic Province. Live oaks are so-called because they keep living leaves on the tree all year, adding young leaves and shedding dead leaves simultaneously rather than dropping dead leaves en masse in the autumn like a true deciduous tree. Coast live oaks may be shrubby, depending on age and growing location, but is generally a medium-sized tree. It grows west of the Sierra Nevada mountain range from Mendocino County, California, south to northern Baja California in Mexico. It is classified in the red oak section of oaks.
Quercus fusiformis, commonly known as escarpment live oak, plateau live oak, plateau oak, or Texas live oak, is an evergreen or nearly evergreen tree. Its native range includes the Quartz Mountains and Wichita Mountains in southwestern Oklahoma, through Texas, to the Mexican states of Coahuila, Tamaulipas, and Nuevo León.
Quercus laurifolia is a medium-sized semi-evergreen oak in the red oak section Quercus sect. Lobatae. It is native to the southeastern and south-central United States.
The fox squirrel, also known as the eastern fox squirrel or Bryant's fox squirrel, is the largest species of tree squirrel native to North America. Despite the differences in size and coloration, it is sometimes mistaken for American red squirrels or eastern gray squirrels in areas where the species co-exist.
Quercus gambelii, with the common name Gambel oak, is a deciduous small tree or large shrub that is widespread in the foothills and lower mountains of western North America. It is also regionally called scrub oak, oak brush, and white oak.
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 vacciniifolia, the huckleberry oak, is a member of the Protobalanus section of genus Quercus. It has evergreen foliage, short styles, very bitter acorns that mature in 18 months, and a woolly acorn shell interior.
Quercus arizonica, the Arizona white oak, is a North American tree species in the beech family. It is found in Arizona, New Mexico, western Texas, Sonora, Chihuahua, Coahuila, Sinaloa, and Durango.
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 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.
The Southeastern conifer forests are a temperate coniferous forest ecoregion of the southeastern United States. It is the largest conifer forest ecoregion east of the Mississippi River. It is also the southernmost instance of temperate coniferous forest within the Nearctic realm.
Quercus subgenus Quercus is one of the two subgenera into which the genus Quercus was divided in a 2017 classification. It contains about 190 species divided among five sections. It may be called the New World clade or the high-latitude clade; most species are native to the Americas, the others being found in Eurasia and northernmost North Africa.
