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 ilex, the evergreen oak, holly oak or holm oak is a large evergreen oak native to the Mediterranean region. It is a member of the Ilex section of the genus, with acorns that mature in a single summer.
Quercus coccifera, the kermes oak, is an oak bush in the Ilex section of the genus. It has many synonyms, including Quercus calliprinos. It is native to the Mediterranean region and Northern African Maghreb, south to north from Morocco to France and west to east from Portugal to Cyprus and Turkey, crossing Spain, Italy, Libya, Balkans, and Greece, including Crete. The Kermes Oak was historically important as the food plant of Kermes scale insects, from which a red dye called crimson was obtained. The etymology of the specific name coccifera is related to the production of red cochineal (crimson) dye and derived from Latin coccum which was from Greek κόκκος, the kermes insect. The Latin -fera means 'bearer'.
Quercus galeanensis is a species of oak tree in the family Fagaceae, native to Northeastern Mexico. The tree is endemic to Mexico, restricted to two subpopulations occupying a narrow band from Galeana in Nuevo León state, to the Miquihuana region in Tamaulipas state. It is an IUCN Red List endangered species, threatened by habitat loss. It is placed in section Lobatae.
Quercus miquihuanensis is a species of oak in the family Fagaceae. It is endemic to the Nuevo León and Tamaulipas states of Mexico. It is an endangered species, threatened by habitat loss. It is placed in section Lobatae.
Quercus vicentensis is a species of oak tree in the family Fagaceae, native to southern Mexico and northern Central America. It is placed in section Quercus.
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 sagrana, also spelt Quercus sagraeana, the Cuban oak, is a medium-sized evergreen tree native to western Cuba in the Cuban pine forests ecoregion. It is the only oak native to the Caribbean.
Quercus franchetii, commonly known as the zhui lian li evergreen oak, is a species of oak in the Ilex section of the genus, native to a wide area of eastern Asia. It is an oak native to China, northern Thailand and Vietnam, growing at altitudes between 800 and 2,600 metres.
Quercus phillyreoides is a species of flowering plant in the genus Quercus, placed in subgenus Cerris and section Ilex. It is evergreen, withstands frost and can be grown in hardiness zone 7. It is native to southern China, the Ryukyu Islands, and Japan, and has been introduced to Korea.
Quercus leucotrichophora is a tree belonging to Family Fagaceae; commonly known as Banjh oak, Banj oak (Uttarakhand) and Ban oak (Himachal). In Nepal, it is known as Banjhi, Rainj, Khasarant, Tikhe bhanjh in standard Nepali and Sulsing in Tamang language. It is classified in subgenus Cerris, section Ilex. Some authors named it as Quercus incana Roxburgh, which is now treated as a synonym.
Quercus semecarpifolia is an Asian species of oak. It is native to the Himalayas and nearby mountains in Tibet, Afghanistan, India, Nepal, and Pakistan, where it is referred to as kharsu. It is classified in subgenus Cerris, section Ilex.
Quercus setulosa is the accepted name of an oak species in genus Quercus of the family Fagaceae. It is now placed in section Ilex of subgenus Cerris.
Bassettia pallida is a species of gall wasp found in the Southern United States. This species was described by American entomologist William Harris Ashmead in 1896. B. pallida reproduces asexually in galls it induces on oak trees. The parasite Euderus set, a eulophid wasp, has B. pallida as a host and manipulates its behavior.
Jeannine Cavender-Bares is a Distinguished McKnight University Professor at the University of Minnesota in the Department of Ecology, Evolution & Behavior. Her research integrates evolutionary biology, ecology, and physiology by studying the functional traits of plants, with a particular focus on oaks.
Quercus aquifolioides is a species of oak native to south-central China and Tibet. It is in the subgenus Cerris, section Ilex. It is a shrub or small tree adapted to high elevations.
Quercus pannosa is a species of oak native to south-central China. An evergreen tree or shrub, it is found at very high elevations, flourishing at up to 4,270 metres above sea level. It is classified in subgenus Cerris, section Ilex.
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.
Quercus subgenus Cerris is one of the two subgenera into which the genus Quercus was divided in a 2017 classification. It contains about 140 species divided among three sections. It may be called the Old World clade or the mid-latitude clade; all species are native to Eurasia and North Africa.
