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|Foliage and acorns of Quercus robur|
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. The second greatest center of oak diversity is China, which contains approximately 100 species.
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.
A shrub or bush is a small- to medium-sized woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. They are distinguished from trees by their multiple stems and shorter height, and are usually under 6 m (20 ft) tall. Plants of many species may grow either into shrubs or trees, depending on their growing conditions. Small, low shrubs, generally less than 2 m (6.6 ft) tall, such as lavender, periwinkle and most small garden varieties of rose, are often termed "subshrubs".
A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.
Oaks have spirally arranged leaves, with lobate margins in many species; some have serrated leaves or entire leaves with smooth margins. Many deciduous species are marcescent, not dropping dead leaves until spring. In spring, a single oak tree produces both male flowers (in the form of catkins) and small female flowers.The fruit is a nut called an acorn or oak nut borne in a cup-like structure known as a cupule; each acorn contains one seed (rarely two or three) and takes 6–18 months to mature, depending on their species. The acorns and leaves contain tannic acid, which helps to guard from fungi and insects. The live oaks are distinguished for being evergreen, but are not actually a distinct group and instead are dispersed across the genus.
In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point.
A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated. They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping. They are found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae. For some time, they were believed to be a key synapomorphy among the proposed Hamamelididae, also known as Amentiferae. Based on molecular phylogeny work, it is now believed that Hamamelididae is a polyphyletic group. This suggests that the catkin flower arrangement has arisen at least twice independently by convergent evolution, in Fagales and in Salicaceae. Such a convergent evolution raises questions about what the ancestral inflorescence characters might be and how catkins did evolve in these two lineages.
A nut is a fruit composed of an inedible hard shell and a seed, which is generally edible. In general usage, a wide variety of dried seeds are called nuts, but in a botanical context "nut" implies that the shell does not open to release the seed (indehiscent). The translation of "nut" in certain languages frequently requires paraphrases, as the word is ambiguous.
The oak tree is a flowering plant. Oaks may be divided into two genera (sometimes referred to as subgenera) and a number of sections:
The flowering plants, also known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families, approximately 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, and the production of fruits that contain the seeds. Etymologically, angiosperm means a plant that produces seeds within an enclosure; in other words, a fruiting plant. The term comes from the Greek words angeion and sperma ("seed").
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections may in turn be divided into subsections.
The genus Quercus is divided into the following sections:
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west and the Mediterranean Sea to the south. It comprises the westernmost part of Eurasia.
Asia is Earth's largest and most populous continent, located primarily in the Eastern and Northern Hemispheres. It shares the continental landmass of Eurasia with the continent of Europe and the continental landmass of Afro-Eurasia with both Europe and Africa. Asia covers an area of 44,579,000 square kilometres (17,212,000 sq mi), about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements, as well as vast barely populated regions. Its 4.5 billion people constitute roughly 60% of the world's population.
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.
In biology, a subgenus is a taxonomic rank directly below genus.
Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.
Castanopsis, commonly called chinquapin or chinkapin, is a genus of evergreen trees belonging to the beech family, Fagaceae. The genus contains about 120 species, which are today restricted to tropical and subtropical eastern Asia. A total of 58 species are native to China, with 30 endemic; the other species occur further south, through Indochina to Indonesia, mountainous areas of Taiwan, and also in Japan. The English name chinkapin is shared with other related plants, including the golden chinkapins of the Pacific United States, which are sometimes included within Castanopsis but are more often considered a separate but very closely related genus, Chrysolepis.
Interspecific hybridization is quite common among oaks but usually between species within the same section only and most common in the white oak group (subgenus Quercus, section Quercus; see List of Quercus species ). Inter-section hybrids, except between species of sections Quercus and Mesobalanus, are unknown. Recent systematic studies appear to confirm a high tendency of Quercus species to hybridize because of a combination of factors. White oaks are unable to discriminate against pollination by other species in the same section. Because they are wind pollinated and they have weak internal barriers to hybridization, hybridization produces functional seeds and fertile hybrid offspring.Ecological stresses, especially near habitat margins, can also cause a breakdown of mate recognition as well as a reduction of male function (pollen quantity and quality) in one parent species.
Frequent hybridization among oaks has consequences for oak populations around the world; most notably, hybridization has produced large populations of hybrids with copious amounts of introgression, and the evolution of new species.Frequent hybridization and high levels of introgression have caused different species in the same populations to share up to 50% of their genetic information. Having high rates of hybridization and introgression produces genetic data that often does not differentiate between two clearly morphologically distinct species, but instead differentiates populations. Numerous hypotheses have been proposed to explain how oak species are able to remain morphologically and ecologically distinct with such high levels of gene flow, but the phenomenon is still largely a mystery to botanists.
The Fagaceae, or beech family, to which the oaks belong, is a very slow evolving clade compared to other angiosperms,and the patterns of hybridization and introgression in Quercus pose a great challenge to the concept of a species since a species is often defined as a group of "actually or potentially interbreeding populations which are reproductively isolated from other such groups." By this definition, many species of Quercus would be lumped together according to their geographic and ecological habitat, despite clear distinctions in morphology and, to a large extent, genetic data.
Oak wood has a density of about 0.75 g / cm3 (0.43 oz/cu in ) creating great strength and hardness. The wood is very resistant to insect and fungal attack because of its high tannin content. It also has very appealing grain markings, particularly when quartersawn. Oak planking was common on high status Viking longships in the 9th and 10th centuries. The wood was hewn from green logs, by axe and wedge, to produce radial planks, similar to quarter-sawn timber. Wide, quarter-sawn boards of oak have been prized since the Middle Ages for use in interior panelling of prestigious buildings such as the debating chamber of the House of Commons in London and in the construction of fine furniture. Oak wood, from Quercus robur and Quercus petraea , was used in Europe for the construction of ships, especially naval men of war, until the 19th century, and was the principal timber used in the construction of European timber-framed buildings. Today oak wood is still commonly used for furniture making and flooring, timber frame buildings, and veneer production.
Barrels in which wines, sherry, and spirits such as brandy, Irish whiskey, Scotch whisky and Bourbon whiskey are aged are made from European and American oak, with single barrel whiskey fetching a premium. The use of oak in wine can add many different dimensions to wine based on the type and style of the oak. Oak barrels, which may be charred before use, contribute to the colour, taste, and aroma of the contents, imparting a desirable oaky vanillin flavour to these drinks. The great dilemma for wine producers is to choose between French and American oakwoods. French oaks (Quercus robur, Q. petraea) give the wine greater refinement and are chosen for the best wines since they increase the price compared to those aged in American oak wood. American oak contributes greater texture and resistance to ageing, but produces more powerful wine bouquets. Oak wood chips are used for smoking fish, meat, cheeses,and other foods.
Japanese oak is used in the making of professional drums from the manufacturer Yamaha Drums. The higher density of oak gives the drum a brighter and louder tone compared to traditional drum materials such as maple and birch. In hill states of India, besides fuelwood and timber, the local people use oak wood for making agricultural implements. The leaves are used as fodder during lean period and bedding for livestock.
The bark of the cork oak is used to produce wine stoppers (corks). This species grows in the Mediterranean Sea region, with Portugal, Spain, Algeria, and Morocco producing most of the world's supply.
Of the North American oaks, the northern red oak is one of the most prized of the red oak group for lumber, much of which is marketed as red oak regardless of the species of origin. It is not good for outdoor use due to its open capillaries unless the wood is treated. If the wood is properly treated with preservatives, it will not rot as quickly as cured white oak heartwood. The closed cell structure of white oaks prevents them from absorbing preservatives. With northern red oak, one can blow air through an end grain piece 10 inches long to make bubbles come out in a glass of water. These openings give fungus easy access when the finish deteriorates. Shumard oak, a member of the red oak subgenus, provides timber which is described as "mechanically superior" to northern red oak. Cherrybark oak is another type of red oak which provides excellent timber.
The standard for the lumber of the white oak group – all of which is marketed as white oak – is the Quercus alba . White oak is often used to make wine barrels. The wood of the deciduous pedunculate oak and sessile oak accounts for most of the European oak production, but evergreen species, such as Holm oak and cork oak also produce valuable timber.
The bark of the white oak is dried and used in medical preparations. Oak bark is also rich in tannin, and is used by tanners for tanning leather. Acorns are used for making flour or roasted for acorn coffee.
Oak galls were used for centuries as a main ingredient in iron gall ink, a kind of manuscript ink, harvested at a specific time of year.In Korea, oak bark is used to make shingles for traditional roof construction.
Oaks are keystone species in a wide range of habitats from Mediterranean semi-desert to subtropical rainforest. For example, oak trees are important components of hardwood forests, and certain species are particularly known to grow in associations with members of the Ericaceae in oak–heath forests.A number of kinds of truffles, including the two well known varieties, the black Périgord truffle and the white Piedmont truffle, have symbiotic relationships with oak trees. Similarly many other mushrooms such as Ramaria flavosaponaria also associate with oaks. The European pied flycatcher is an example of an animal species that often depends upon oak trees.
Many species of oaks are under threat of extinction in the wild, largely due to land use changes, livestock grazing and unsustainable harvesting. For example, over the past 200 years, large areas of oak forest in the highlands of Mexico, Central America and the northern Andes have been cleared for coffee plantations and cattle ranching. There is a continuing threat to these forests from exploitation for timber, fuelwood and charcoal.In the USA, entire oak ecosystems have declined due to a combination of factors still imperfectly known, but thought to include fire suppression, increased consumption of acorns by growing mammal populations, herbivory of seedlings, and introduced pests. In a recent survey, 78 wild oak species have been identified as being in danger of extinction, from a global total of over 500 species. The proportion under threat may be much higher in reality, as there is insufficient information about over 300 species, making it near impossible to form any judgement of their status.
In the Himalayan region of India, oak forests are being invaded by pine forests due to the increase in temperature. The associated species of pine forest may cross frontiers and become new elements of the oak forests.
In eastern North America, rare species of oak trees include scarlet oak ( Quercus coccinea ), chinkapin oak ( Quercus muehlenbergii ), and post oak ( Quercus stellata ).
The mature trees shed varying numbers of acorns annually. Scientists suggest that shedding excess numbers allows the oaks to satiate nut gathering species, improving the chances of germination. Every four to ten years, certain oak populations will synchronize to produce almost no acorns at all, only to rain them down excessively the following year, known as a "mast" year. The year preceding the mast year is thought to starve off the mammal populations feeding on the supply, thereby increasing the effectiveness of the overproduction in the mast year that follows.This is necessary to the survival of any given oak species, as only one in 10,000 acorns results in an eventual tree.
Beginning 1 November 2011, a project began to sequence the entire oak genome. The goal of the project is to create a high resolution sequence of the Quercus robur genome, and to study genetic diversity by comparison of the genomes of different species.Current research has compiled genomic data from many different sources and techniques to create a genome map with 89% coverage of the genome. The project is still in the process of annotating this genome.
Sudden oak death (Phytophthora ramorum) is a water mould that can kill oaks within just a few weeks. Oak wilt, caused by the fungus Ceratocystis fagacearum (a fungus closely related to Dutch elm disease), is also a lethal disease of some oaks, particularly the red oaks (the white oaks can be infected but generally live longer). Other dangers include wood-boring beetles, as well as root rot in older trees which may not be apparent on the outside, often being discovered only when the trees come down in a strong gale. Oak apples are galls on oaks made by the gall wasp. The female kermes scale causes galls to grow on kermes oak. Oaks are used as food plants by the larvae of Lepidoptera (butterfly and moth) species such as the gypsy moth, Lymantria dispar, which can defoliate oak and other broadleaved tree species in North America.
A considerable number of galls are found on oak leaves, buds, flowers, roots, etc. Examples are oak artichoke gall, oak marble gall, oak apple gall, knopper gall, and spangle gall.
A number of species of fungus cause powdery mildew on oak species. In Europe the species Erysiphe alphitoides is the most common cause.
A new and yet little understood disease of mature oaks, acute oak decline, has been reported in parts of the UK since 2009.
Oak processionary moth (Thaumetopoea processionea) has become a serious threat in the UK since 2006. The caterpillars of this species defoliate the trees, and are hazardous to human health; their bodies are covered with poisonous hairs which can cause rashes and respiratory problems.
In California, oaks are affected by the fungal disease Foamy bark canker.
The leaves and acorns of the oak tree are poisonous to cattle, horses, sheep, and goats in large amounts due to the toxin tannic acid, and cause kidney damage and gastroenteritis. Symptoms of poisoning include lack of appetite, depression, constipation, diarrhea (which may contain blood), blood in urine, and colic. The exception to livestock and oak toxicity is the domestic pig, which may be fed entirely on acorns in the right conditions, and has traditionally been pastured in oak woodlands (such as the Spanish dehesa and the English system of pannage) for hundreds of years.
Acorns are also edible to humans, after leaching of the tannins.
The oak is a common symbol of strength and endurance and has been chosen as the national tree of many countries. Already an ancient Germanic symbol (in the form of the Donar Oak, for instance), certainly since the early nineteenth century, it stands for the nation of Germany and oak branches are thus displayed on some German coins, both of the former Deutsche Mark and the current Euro currency.In 2004 the Arbor Day Foundation held a vote for the official National Tree of the United States of America. In November 2004, the United States Congress passed legislation designating the oak as America's National Tree.
Other countries have also designated the oak as their national tree including Bulgaria, Cyprus (Golden Oak), England, Estonia, France, Germany, Moldova, Jordan, Latvia, Lithuania, Poland, Romania, Serbia, and Wales.
The oak is the emblem of County Londonderry in Northern Ireland, as a vast amount of the county was covered in forests of the tree until relatively recently. The name of the county comes from the city of Derry, which originally in Irish was known as Doire meaning oak.
The Irish County Kildare derives its name from the town of Kildare which originally in Irish was Cill Dara meaning the Church of the Oak or Oak Church.
Iowa designated the oak as its official state tree in 1961; and the White Oak is the state tree of Connecticut, Illinois and Maryland. The Northern Red Oak is the provincial tree of Prince Edward Island, as well as the state tree of New Jersey. The Live Oak is the state tree of Georgia, USA.
The oak is a national symbol from the Basque Country, specially in the province of Biscay.
The oak is a symbol of the East Bay of the San Francisco Bay Area; the coat-of-arms and flag of Oakland, California feature the oak and the logo of the East Bay Regional Park District is an oak leaf.
The coat-of-arms of Vest-Agder, Norway, and Blekinge, Sweden, features oak trees.
The coat-of-arms of the municipality Eigersund, Norway features an oak leaf.
Oak leaves are traditionally an important part of German Army regalia.[ citation needed ] The Nazi party used the traditional German eagle, standing atop of a swastika inside a wreath of oak leaves. It is also known as the Iron Eagle. During the Third Reich of Nazi Germany, oak leaves were used for military valor decoration on the Knights Cross of the Iron Cross. They also symbolize rank in the United States Armed Forces. A gold oak leaf indicates an O-4 (Major or Lt. Commander), whereas a silver oak leaf indicates an O-5 (Lt. Colonel or Commander). Arrangements of oak leaves, acorns and sprigs indicate different branches of the United States Navy Staff corps officers. Oak leaves are embroidered onto the covers (hats) worn by field grade officers and flag officers in the United States armed services.
If a member of the United States Army or Air Force earns multiple awards of the same medal, then instead of wearing a ribbon or medal for each award, he or she wears one metal representation of an "oak leaf cluster" attached to the appropriate ribbon for each subsequent award.
The oak tree is used as a symbol by a number of political parties. It is the symbol of Toryism (on account of the Royal Oak) and the Conservative Party in the United Kingdom,and formerly of the Progressive Democrats in Ireland and the Democrats of the Left in Italy. In the cultural arena, the oakleaf is the symbol of the National Trust (UK), The Woodland Trust, and The Royal Oak Foundation.
In Greek mythology, the oak is the tree sacred to Zeus, king of the gods. In Zeus's oracle in Dodona, Epirus, the sacred oak was the centerpiece of the precinct, and the priests would divine the pronouncements of the god by interpreting the rustling of the oak's leaves.
In Baltic and Slavic mythology, the oak is the sacred tree of Latvian Pērkons, Lithuanian Perkūnas, Prussian Perkūns and Slavic Perun,the god of thunder and one of the most important deities in the Baltic and Slavic pantheons.
In Celtic polytheism, the name of the oak tree was part of the Proto-Celtic word for 'druid': *derwo-weyd- > *druwid-; however, Proto-Celtic *derwo- (and *dru-) can also be adjectives for 'strong' and 'firm', so Ranko Matasovic interprets that *druwid- may mean 'strong knowledge'. As in other Indo-European faiths, Taranis, being a thunder god, was associated with the oak tree.The Indo-Europeans worshiped the oak and connected it with a thunder or lightning god; "tree" and drus may also be cognate with "Druid," the Celtic priest to whom the oak was sacred. There has even been a study that shows that oaks are more likely to be struck by lightning than any other tree of the same height.
In Norse mythology, the oak was sacred to the thunder god, Thor. Thor's Oak was a sacred tree of the Germanic Chatti tribe.
In the Bible, the oak tree at Shechem is the site where Jacob buries the foreign gods of his people (Gen. 35:4) . In addition, Joshua erects a stone under an oak tree as the first covenant of the Lord (Josh. 24.25–7). In Isaiah 61, the prophet refers to the Israelites as "Oaks of Righteousness." Absalom's long hair (2 Samuel 18:9) gets caught in an oak tree, and allows Joab to kill him.
The badnjak is central tradition in Serbian Orthodox Church Christmas celebration where young and straight oak, is ceremonially felled early on the morning of Christmas Eve.
In some traditions of Wicca, the Oak King is one of the two faces of the Sun God. He is born on Yule and rules from Ostara to Mabon.[ citation needed ]
Several singular oak trees, such as the Royal Oak in Britain and the Charter Oak in the United States, are of great historical or cultural importance; for a list of important oaks, see Individual oak trees.
"The Proscribed Royalist, 1651", a famous painting by John Everett Millais, depicted a Royalist fleeing from Cromwell's forces and hidden in an oak. Millais painted the picture in Hayes, Kent, from a local oak tree that became known as the Millais Oak.
Approximately 50 km west of Toronto, Canada is the town of Oakville, ON, famous for its history as a shipbuilding port on Lake Ontario.[ clarification needed ]
The city of Raleigh, N.C., is known as "The City of Oaks."
The Jurupa Oak tree – a clonal colony of Quercus palmeria or Palmer’s oak found in Riverside County, California – is an estimated 13,000 years old.
Large groups of very old oak trees are rare[ why? ]. One of the oldest groups of oak trees, found in Poland, is about 480 years old, which was assessed by dendrochronological methods.
In the Roman Republic, a crown of oak leaves was given to those who had saved the life of a citizen in battle; it was called the "civic oak crown".
Linnaeus described only five species of oak from eastern North America, based on general leaf form. These were white oak, Quercus alba; chestnut oak, Q. montana; red oak, Q. rubra; willow oak Q. phellos; and water oak, Q. nigra. Because he was dealing with confusing leaf forms, the Q. montana and Q. rubra specimens actually included mixed foliage of more than one species.
Quercus rubra, commonly called northern red oak or champion oak, is an oak 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 grows from the north end of the Great Lakes, east to Nova Scotia, south as far as Georgia, Alabama, and Louisiana, and west to Oklahoma, Kansas, Nebraska, and Minnesota. 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, also known as the Spanish oak. It is also the state tree of New Jersey and the provincial tree of Prince Edward Island.
Quercus montana, the chestnut oak, is a species of oak in the white oak group, Quercus sect. Quercus. It is native to the eastern United States, where it is one of the most important ridgetop trees from southern Maine southwest to central Mississippi, with an outlying northwestern population in southern Michigan. It is also sometimes called "rock oak" because of its presence in montane and other rocky habitats. As a consequence of its dry habitat and ridgetop exposure, it is not usually a large tree, typically 18–22 m (59–72 ft) tall; occasional specimens growing in better conditions can however become large, with trees up to 40–43 m (131–141 ft) tall known. They tend to have a similar spread of 18–22 m (59–72 ft). A 10-year-old sapling grown in full sun will stand about 5 m (16 ft) tall. This species is often an important canopy species in an oak-heath forest.
Quercus alba, the white oak, is one of the preeminent hardwoods of eastern and central North America. It is a long-lived oak, native to eastern and central North America and found from Minnesota, Ontario, Quebec, and southern Maine south as far as northern Florida and eastern Texas. Specimens have been documented to be over 450 years old.
Quercus muehlenbergii, the chinkapin oak, is an oak 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, ranging from Vermont west to Wisconsin and south to South Carolina, western Florida, New Mexico, and northeastern Mexico from Coahuila south to Hidalgo.
Quercus velutina, the eastern black oak or more commonly known as simply black oak, is a species in the red oak group of oaks. It is widespread in eastern and central North America, found in all the coastal states from Maine to Texas, inland as far as Michigan, Ontario, Minnesota, Nebraska, Kansas, Oklahoma, and eastern Texas.
Quercus robur, commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is native to most of Europe west of the Caucasus. The tree is widely cultivated in temperate regions and has escaped into the wild in scattered parts of China and North America.
Quercus ilex, the evergreen oak, holly oak or holm oak, is a large evergreen oak native to the Mediterranean region. It takes its name from holm, an ancient name for holly. It is a member of the Cerris section of the genus, with acorns that mature in a single summer.
Quercus garryana, the Garry oak, Oregon white oak, or Oregon oak, is a tree species with a range stretching from southern California to southwestern British Columbia. It grows from sea level to 210 meters (690 ft) altitude in the northern part of its range, and at 300 to 1,800 meters in the south of the range in California. The eponymous Nicholas Garry was deputy governor of the Hudson's Bay Company, 1822–35.
Quercus cerris, the Turkey oak or Austrian oak, is an oak native to south-eastern Europe and Asia Minor. It is the type species of Quercus sect. Cerris, a section of the genus characterised by shoot buds surrounded by soft bristles, bristle-tipped leaf lobes, and acorns that usually mature in 18 months.
Quercus petraea, commonly known as the sessile oak, Cornish oak, or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran.
Quercus virginiana, also known as the southern live oak, is an evergreen oak tree native 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 southern United States.
Quercus macrocarpa, the bur oak, sometimes spelled burr oak, is a species of oak in the white oak section Quercus sect. Quercus, native to North America in the eastern and central United States and eastern and central Canada. This plant is also called mossycup oak and mossycup white oak.
Quercus stellata, the post oak or iron oak, is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry, poor soils, and is resistant to rot, fire, and drought. Interbreeding occurs among white oaks, thus many hybrid species combinations occur.
Quercus lobata, commonly called the valley oak or roble, grows into the largest of North American 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.
Quercus faginea, the Portuguese oak or Valencian oak, is a species of oak native to the western Mediterranean region in the Iberian Peninsula and the Balearic Islands. Similar trees in the Atlas Mountains of northwest Africa are usually included in this species, or sometimes treated as a distinct species Quercus tlemcenensis. It occurs in mountains from sea level to 1900 m altitude, and flourishes in a variety of soils and climates.
Quercus nigra, the water oak, is an oak in the red oak group, native to the eastern and south-central United States, found in all the coastal states from New Jersey to Texas, and inland as far as Oklahoma, Kentucky, and southern Missouri. It occurs in lowlands and up to 450 m (1500 ft) altitude.
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 rapid identification arises from the leaves of canyon live oak being geometrically flat. They are often sympatric with Quercus agrifolia and several other oak species. Fossil data supports a much wider distribution throughout the western United States during the early Holocene period.
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 leucotrichophora is a tree belonging to Family Fagaceae; commonly known as Banjh oak. In Nepal, it is known as Banjhi, Rainj, Khasarant, Tikhe bhanjh in Standard Nepali and Sulsing in Tamang language. Some authors named it as Quercus incana Roxburgh.
|url=(help). Taylor & Francis, Ltd. 77 (6): 903–919. doi:10.2307/3793302. ISSN 0027-5514. JSTOR 3793302. OCLC 7377077277.
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