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 in 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 kelloggii, the California black oak or Kellogg oak, is an oak in the red oak section native to western North America. Although genetically separated from them for more than 20 million years, its leaves are remarkably similar in appearance to several other members of the red oak section including the red oak and the black oak found in eastern and central North America.
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 garryana is an oak tree species of the Pacific Northwest, with a range stretching from southern California to southwestern British Columbia. It is commonly known as the Garry Oak, Oregon white oak or Oregon oak. It grows from sea level to an altitude of 690 feet in the northern part of its range, and from 980 to 5,900 ft in the south of the range in California. The eponymous Nicholas Garry was deputy governor of the Hudson's Bay Company.
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 agrifolia, the California live oak, or coast live oak, is a highly variable, often evergreen oak tree, a type of live oak, native to the California Floristic Province. It 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 coccinea, the scarlet oak, is a deciduous tree in the red oak section Lobatae of the genus Quercus, in the family Fagaceae.
Aesculus californica, commonly known as the California buckeye or California horse-chestnut, is a species of buckeye native to California and southwestern Oregon.
Quercus lobata, commonly called the valley oak or roble, grows into the largest of California oaks. It is endemic to California, growing in interior valleys and foothills from Siskiyou County to San Diego County. Mature specimens may attain an age of up to 600 years. This deciduous oak requires year-round access to groundwater.
Salinan was the indigenous language of the Salinan people of the central coast of California. It has been extinct since the death of the last speaker in 1958.
California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico. Oak woodland is widespread at lower elevations in coastal California; in interior valleys of the Coast Ranges, Transverse Ranges and Peninsular Ranges; and in a ring around the California Central Valley grasslands. The dominant trees are oaks, interspersed with other broadleaf and coniferous trees, with an understory of grasses, herbs, geophytes, and California native plants.
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 durata, commonly known as leather oak, is a species of oak endemic to California, common in the Coast Ranges and the foothills of the Sierra Nevada. The common name "leather oak" is derived from the leathery texture on the lop of its leaves. Taxonomically it is placed in the white oak group.
Quercus dumosa is a species of plant in the family Fagaceae, belonging to the white oak section of the oak genus (Quercus). This tree goes by the common names coastal sage scrub oak and Nuttall's scrub oak.
Quercus × alvordiana, the Alvord oak, is a hybrid oak in the genus Quercus. It has been reported to be a hybrid between Quercus douglasii and Quercus turbinella, or between Q. douglasii and Quercus john-tuckeri, which was formerly considered to be a variety of Q. turbinella.
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 turbinella is a North American species of oak known by the common names shruboak, 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 pacifica is a species of oak known by the common names island scrub oak, Channel Island scrub oak, and Pacific oak.
Notholithocarpus densiflorus, commonly known as the tanoak or tanbark-oak, is a broadleaf tree in the family Fagaceae, and the type species of the genus Notholithocarpus. It is native to the far western United States, particularly Oregon and California. It ranges from 15–40 meters in height, with a trunk diameter of 60–190 centimeters.
An oak woodland is a plant community with a tree canopy dominated by oaks. In terms of canopy closure, oak woodlands are intermediate between oak savanna, which is more open, and oak forest, which is more closed. Although the community is named for the dominance of oak trees, the understory vegetation is often diverse and includes many species of grasses, sedges, forbs, ferns, shrubs, and other plants.
Leaves and acorn
Leaves in lobed form
