A tree usually 15–18 meters (50–60 feet) high, maximum height 100 ft, with broad pyramidal head when young, becoming in old age broad-topped and open. Trunk up to 1 m (40 inches) in diameter (rarely 1.4 m or 56 in). It reaches its largest size in southern Illinois and Indiana, although the national champion is 104' by 68' in Cincinnati, Ohio.
Bark: Light brown, scaly; on young stems light brown, smooth.  Branchlets slender, dark green and shining at first, later become light brown, finally dark brown.
Wood: Pale reddish brown, sapwood lighter; heavy, hard coarse-grained, checks badly in drying; used for shingles and sometimes in construction.  Sp. gr., 0.7529; weight of cu. ft., 46.92 lbs.
Winter buds: Light brown, ovate, acute, one-eight inch long.
Leaves: Alternate, oblong or obovate, four to six inches long, one to two inches wide, wedge-shaped or rounded at base, acute or rounded at apex, sometimes entire or with undulated margins, sometimes more or less three-lobed.  They come out of the bud involute, bright red, covered with rusty down above and white tomentum below.  When full grown are dark green, smooth and shining above, pale green or pale brown, downy below; midribs stout yellow, grooved above, primary veins slender.  In autumn they become dark red above, pale beneath, midribs darken, then the leaf.  Petioles stout, hairy, flattened, grooved.  Stipules about one-half inch long, caducous.
Flowers: May, when leaves are half grown.  Staminate flowers borne on tomentose aments two to three inches long.  Bracts linear-lanceoate.  Calyx pale yellow, downy, four-lobed; stamens four to five; anthers yellow.  Pistillate flowers borne on slender tomentose peduncles.  Involucres scales are downy, about as long as the calyx lobes; stigmas short, reflexed, greenish-yellow.
Acorns: Ripen in autumn of second year, about 18 months after pollination. Stalked, solitary or in pairs; nut almost spherical, 9–18 millimeters or 1⁄2 to 2⁄3 in long; cup embraces one-half to two-thirds nut, is cup-shaped covered with light red brown, downy scales, rounded or acute at apex. Kernel very bitter.
It is distinguished from most other oaks by its leaves, which are shaped like laurel leaves, 8–20 cm (4–10 in) long and 1.5–7.5 cm (1⁄2–3 in) broad with an untoothed margin; they are bright green above, paler and somewhat downy beneath.


It is native primarily to the Midwestern and Upper South regions of North America, from southern New York west to northern Illinois and eastern Kansas, and south to central Alabama and Arkansas. It is abundant in the lower Ohio Valley and middle Mississippi Valley, and rare in the east.
It is most commonly found growing in uplands with good drainage, less often along lowland streams, at altitudes of 100–700 m (330–2,300 ft).


In the past, the wood was important for making shingles, from which the common name derives.


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.
Its thick, ridged bark is characteristic and resembles alligator hide. The valley oak's deeply lobed leaves assist in identification.


The valley oak may surpass 30 meters (98 feet) in height, with a sturdy trunk possibly exceeding 3 m (10 ft) in diameter. The "Henley Oak", in Covelo, California, is the tallest known valley oak, at 47 m (153 ft).
The branches have an irregular, spreading and arching appearance that produce a profound leafless silhouette in the clear winter sky. During autumn, the leaves turn a yellow to light orange color but become brown later in the season. In advancing age, the branches assume a drooping characteristic. The tree's pewter-colored rippled bark adds to the attractive aesthetic of this species.
Typically, the leaves are 5–10 centimeters (2–4 inches) long and are roundly and deeply lobed. The leaf width is approximately one half its length. Each leaf is matte green with an underneath pale green appearance; moreover, the leaf is covered with abundant soft fuzz, yielding an almost velvety feeling. When a fresh leaf is rubbed or broken, an aromatic scent is exuded, evoking a forest odor. The wood is a dull brown approaching yellow.
The acorns are medium to dark brown and range from 2 to 3 cm (3⁄4 to 1+1⁄4 in) in length. The caps have deep stippling and are found most often as singlets, but occasionally as doublets. The acorns ripen from October to November. Viable acorns germinate in their first winter, and none remain by mid-winter.


Valley oak is of the white oak evolutionary lineage, which is officially known as the subgenus Lepidobalanus. This subgenus comprises numerous oaks from California and elsewhere, which species share similar leaves, acorns, bark and wood pulp. Early settlers used a variety of common names for the valley oak including: white oak, bottom oak, swamp oak, water oak and mush oak. The Spaniards, because the tree looked like the white oaks in Europe, called the tree "roble".
The Concow tribe call the acorns lō-ē’ (Konkow language).


Valley oak tolerates cool wet winters and hot dry summers, but requires abundant water. It is most abundant in rich deep soils of valley floors below 600 meters (2000 feet) in elevation. Valley oak is found in dense riparian forests, open foothill woodlands and valley savannas. Commonly associated trees are coast live oak, interior live oak, blue oak, California black walnut, California sycamore and gray pine.
The valley oak is widely distributed in: the California Central Valley; many smaller valleys such as the San Fernando Valley (original Spanish place-name from oak savannah), Conejo Valley, and Santa Ynez Valley; the Inner Coast Ranges south of the Eel River; and the Transverse Ranges from the Tehachapi Mountains to the Simi Hills, Santa Susana Mountains. It is also present on Santa Cruz Island and Catalina Island in the Pacific Ocean. Some of the most picturesque stands are found in Sonoma Valley, Round Valley in Mendocino County and the southern Salinas Valley near the up-river reaches of the Salinas River.


Like many oaks, valley oaks can tolerate wildfires. Although smaller individuals may be top-killed, most resprout from the root crown.
A variety of mammals and birds eat the acorns, including the acorn woodpecker, California scrub jay, yellow-billed magpie, and California ground squirrel. The acorns are also attacked by bruchid beetles, but can survive moderate levels of infestation.
Globular galls up to several centimeters in diameter are frequently attached to twigs of mature specimens of valley oak. These house the larval stage of small indigenous wasps Andricus quercuscalifornicus. A related wasp species, A. kingi, produces small galls shaped like Hershey's kisses on leaf surfaces. The valley oak is the only known food plant of Chionodes petalumensis caterpillars.


The acorns are sweet and edible; Native Americans including the Southern Paiute people roasted them and ground the edible portion into meal to make into bread and mush.
Difficulties in acquiring valley oak wood as well as issues stemming from its drying such as cracking and warping have shifted its consumption from a general purpose lumber to a primarily niche product. Valley oak wood has a small, but significant market for use in cabinetry though, and is also suitable for hardwood flooring. Tyloses present in the pores of valley oak wood increase its impermeability to fluids allowing it to be used in the production of water-tight vessels. Such vessels include wine barrels where valley oak wood sees limited role in the composition of and where it has similar properties to other white oaks such as a reduced tannin load compared to the red oaks and an open grain that allows for an increased transfer of oxygen.


Quercus macrocarpa, the bur oak, commonly spelled 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 (thus the species name macrocarpa, from Ancient Greek μακρός makrós "large" and καρπός karpós "fruit"), and are important food for wildlife.


Quercus macrocarpa is a large deciduous tree growing up to 30 metres (98 feet), rarely 50 m (160 ft), in height, and is one of the most massive oaks with a trunk diameter of up to 3 m (10 ft); reports of taller trees occur, but have not been verified. It is one of the slowest-growing oaks, with a growth rate of 30 centimetres (1 ft) per year when young. However, other sources state that a bur oak tree that is planted in the ground grows up to 91 cm (3 ft) per year. A 20-year-old tree will be about 18 m (60 ft) tall if grown in full sun. Naturally occurring saplings in forests will typically be older. Bur oaks commonly get to be 200 to 300 years old, and may live up to 400 years. The bark is gray with distinct vertical ridges.
The leaves are 7–15 cm (2+3⁄4–6 in) long and 5–13 cm (2–5 in) broad, variable in shape, with a lobed margin. Most often, the basal two-thirds is narrower and deeply lobed, while the apical third is wider and has shallow lobes or large teeth. They usually do not show strong fall color, although fine golden hues are occasionally seen. The flowers are greenish-yellow catkins, produced in the spring. The acorns are very large, 2.5–5 cm (1–2 in) long and 2–4 cm (3⁄4–1+1⁄2 in) broad, having a large cup that wraps much of the way around the nut, with large overlapping scales and often a fringe at the edge of the cup.
The wood when sawn transversely shows the characteristic annual rings formed by secondary thickening.
Bur oak is sometimes confused with other members of the white oak section, such as Quercus bicolor (swamp white oak), Quercus lyrata (overcup oak), and Quercus alba (white oak). It hybridises with several other species of oaks.


Two varieties are accepted in Kew's Plants of the World Online:
Quercus macrocarpa var. macrocarpa
Quercus macrocarpa var. depressa (Nutt.) Engelm.


Quercus macrocarpa is widespread in the Atlantic coastal plain from New Brunswick to North Carolina, west as far as Alberta, eastern Montana, Wyoming, and northeastern New Mexico. The vast majority of the populations are found in the eastern Great Plains, the Mississippi–Missouri–Ohio Valley, and the Great Lakes region.
Bur oaks primarily grow in a temperate climate on the western oak–hickory forested regions in the United States and into Canada. It commonly grows in the open, away from dense forest canopy. For this reason, it is an important tree on the eastern prairies, often found near waterways in otherwise more forested areas, where there is a break in the canopy. It is drought resistant, possibly because of its long taproot. At the end of the growing season, a one-year sapling may have a taproot 1.37 m (4+1⁄2 ft) deep and a lateral root spread of 76 cm (2+1⁄2 ft). The West Virginia state champion bur oak has a trunk diameter of almost 3 m (10 ft).
Large bur oaks, older than 12 years, are fire-tolerant because of their thick bark. One of the bur oak's most common habitats, especially in Midwestern United States, is the oak savanna, where fires often occurred in early spring or late fall. Without fires, bur oak is often succeeded by other tree and shrub species that are more shade-tolerant. Older bur oaks may survive in dense woodlands for 80 years, until they are weakened by wood-rot fungi in the lower branches killed by shade, and by 100 to 110 years, they are often snapped by wind storms.


The acorns are the largest of any North American oak and are an important wildlife food; American black bears sometimes tear off branches to get them. However, heavy nut crops are borne only every few years. In this evolutionary strategy, known as masting, the large seed crop every few years overwhelms the ability of seed predators to eat the acorns, thus ensuring the survival of some seeds. Other wildlife, such as deer and porcupine, eat the leaves, twigs and bark. Cattle are heavy browsers in some areas. The bur oak is the only known foodplant of Bucculatrix recognita caterpillars.
Many species of arthropods form galls on the leaves and twigs, including Aceria querci (a mite) and numerous cynipid wasps:  Acraspis macrocarpae, Acraspis villosa, Andricus chinquapin, Andricus dimorphus, Andricus foliaformis, Andricus flavohirtus, Andricus quercuspetiolicola, Callirhytis flavipes, Disholcaspis quercusmamma, Neuroterus floccosus, Neuroterus saltarius, Neuroterus umbilicatus, Philonix nigra, and Phylloteras poculum.


Bur oak blight is caused by a fungal pathogen Tubakia iowensis. It forms black pustules on the petioles and causes leaf discoloration and death, making the tree more susceptible to other secondary issues such as Armillaria root rot or Agrilus bilineatus (two-lined chestnut borer).


Quercus macrocarpa is cultivated by plant nurseries for use in gardens, in parks, and on urban sidewalks. Among the white oaks, it is one of the most tolerant of urban conditions, and is one of the fastest-growing of the group. It has been planted in many climates, ranging northwards to Anchorage, Alaska, and as far south as Mission, Texas. It withstands chinook conditions in Calgary, Alberta. It is drought tolerant.
Coppicing has been shown to produce superior growth.


The wood of Quercus macrocarpa is commercially valuable; it is durable, used for flooring, fence posts, cabinets, and barrels. The acorns can be eaten boiled and raw. Native Americans have used the astringent bark to treat wounds, sores, rashes, and diarrhea.


Quercus marilandica, the blackjack oak, is a small oak, one of the red oak group Quercus sect. Lobatae. It is native to the eastern and central United States.


Quercus marilandica is a small deciduous tree growing to 15 meters (49 feet) tall, with bark cracked into rectangular black plates with narrow orange fissures. The leaves are 7–20 centimeters (3–8 inches) long and broad, and typically flare from a tapered base to a broad three-lobed bell shape with only shallow indentations. They are dark green and glossy above, pubescent underneath, and often remain attached to the twigs through the winter after turning colors from red to brown in the fall. The acorn is small, 12–20 millimeters (1⁄2–3⁄4 in) long and 10–18 mm (3⁄8–3⁄4 in) broad; like those of other red oaks, it takes 18 months to mature.
Blackjack oaks in the Cross Timbers can grow from 15 to 18 m (50 to 60 ft) high but seldom reach more than 12 m (40 ft), with a trunk diameter of 41 cm (16 in). The leaves are from 10 to 25 cm (4 to 10 in) in length and about the same width.


The blackjack oak can be found from Long Island to Florida, west as far as Texas, Oklahoma, and Nebraska. There are reports of a few isolated populations in southern Michigan, but these appear to represent introductions.
The species grows in poor, thin, dry, rocky or sandy soils where few other woody plants can thrive, usually on low ground, from sea level up to approximately 850 m (2,800 ft) in altitude. Some sources say that it does not have the beautiful form of many oaks, but is nonetheless a valuable tree for growing in problem sites. Some say that the tree is "tough but ugly", but also underappreciated. At times the tree has even been actively eradicated to provide room for trees deemed to be more commercially valuable.
It is sometimes an understory tree in pine stands on sandy knolls in the southeastern US. Along the coastal plain of New Jersey the probability of finding this species is increased in relatively sunny, open areas such as those near coastal salt marshes. It often occurs near scarlet and post oaks as well as pitch pine; understory companions include winged sumac, bracken, sweetfern, and bayberry, and can be found as far north as parts of Ohio and New York.
A variety, Quercus marilandica Münchhausen var. ashei Sudworth, grows in the western portions of its range – northern Texas, Oklahoma, and into southern Kansas. In this area, blackjack and post oak form a semi-savanna area composed of forested strips intermixed with prairie grass glades along the eastern edge of the southern Great Plains. This semi-savanna is known as the Cross Timbers. Scrub forms of Q. marilandica dominate on many chert glades along with Q. stellata in Arkansas's Ozark plateau.


Blackjack oak sometimes hybridizes with bear oak (Q. ilicifolia), forming a hybrid known as Q. × brittonii.
Blackjack acorns provide food for both whitetail deer and wild turkey. Blackjacks may, however, cause tannic acid poisoning in cattle.


The wood is very dense and produces a hot flame when burned, which functions as an excellent source of heat for barbecues and wood-burning stoves. However, the wood is not desirable for wood fireplaces because the heat causes popping, thereby increasing the risk of house fires.
Traditionally blackjack wood is used as both a fuel and smoke wood for barbecue in Oklahoma.


Quercus michauxii, the swamp chestnut oak, is a species of oak in the white oak section Quercus section Quercus in the beech family. It is native to bottomlands and wetlands in the southeastern and midwestern United States, in coastal states from New Jersey to Texas, inland primarily in the Mississippi–Ohio Valley as far as Oklahoma, Missouri, Illinois, and Indiana.


The leaves of the swamp chestnut oak are simple (not compound), 4–11 inches (10–28 centimetres) long and 2–7 in (5–18 cm) broad, with 15–20 lobe-like, rounded simple teeth on each side, similar to those of chestnut oak and chinkapin oak (Quercus muehlenbergii), although they generally do not achieve the more slender form that the leaves of those trees may exhibit at times. The leaves turn red in autumn. The fruit is an acorn 2.5–3.5 cm (1–1+1⁄2 in) long and 2–2.5 cm (3⁄4–1 in) broad, borne on a 2–3 cm peduncle, maturing in the fall, about 6 months after pollination. The tree only bears heavy acorn crops at intervals of several years.


The swamp chestnut oak closely resembles the chestnut oak (Quercus montana), and for that reason has sometimes been treated as a variety of that species. However, the swamp chestnut oak is a larger tree which differs in preferred habitat, and the bark does not have the distinctive deep, rugged ridging of the chestnut oak, being thinner, scaly, and paler gray. It typically grows to around 65 ft (20 m) tall, though the tallest specimen currently known is over 150 ft (42 m) tall.
The name Q. prinus was long used by many botanists and foresters for the swamp chestnut oak, even when treated as a species distinct from the chestnut oak, which was then called Q. montana, but the application of the name Q. prinus to the chestnut oak is now often accepted, although sometimes that name is declared to be of uncertain position, unassignable to either species, with the chestnut oak then called Q. montana, as in the Flora of North America.


The acorns of the swamp chestnut oak are eaten by generalist species like chipmunks, squirrels, white-tail deer, wild hogs, and black bears. They are also readily eaten by cattle,  and the species is sometimes called the "cow oak" for this reason.


The wood of the swamp chestnut oak is similar to, and usually marketed mixed with, that of other white oaks. Swamp chestnut oak is also called basket oak, since the wood is easily split into long, thin, flexible strips excellent for basket weaving.
The swamp chestnut oak's acorns are large, relatively sweet, and edible.
The swamp chestnut oak is sometimes cultivated as a large garden tree or street tree, and is quite easy to grow if it is not subject to extreme urban conditions. The current National Champion Swamp Chestnut Oak is in the Stumpy Lake area in Virginia Beach, Virginia. It is 123 ft (37 m) high, with a crown of 109 ft (33 m) and a circumference of 23 ft (7 m).


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, the chestnut oak is not usually a large tree, typically growing to 18–22 metres (59–72 feet) tall; specimens growing in better conditions can grow up to 40–43 m (131–141 ft) tall. 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.
It is readily identified by its massively-ridged dark gray-brown bark, the thickest of any eastern North American oak. The leaves are 12–20 centimetres (4+3⁄4–7+3⁄4 inches) long and 6–10 cm (2+1⁄4–4 in) broad, shallowly lobed with 10–15 rounded lobes on each margin; they are virtually identical to the leaves of swamp chestnut oak and chinkapin oak, but the trees can readily be distinguished by the bark, that of the chinkapin oak being a light ash-gray and somewhat peeling like that of the white oak and that of swamp chestnut oak being paler ash-gray and scaly. The chinkapin oak also has much smaller acorns than the chestnut oak. The chestnut oak is easily distinguished from the swamp white oak because that tree has whitened undersides on the leaves. Another important distinction between the chestnut oak and the swamp chestnut oak is by the habitat; if it grows on a ridge, it is chestnut oak, and if it grows in wet bottomlands, it is probably the more massive swamp chestnut oak; however, this is not fully reliable.
Characteristics include:
Bark: Dark, fissured into broad ridges, scaly. Branchlets stout, at first bronze green, later they become reddish brown, finally dark gray or brown. Heavily charged with tannic acid.
Wood: Dark brown, sapwood lighter; heavy, hard, strong, tough, close-grained, durable in contact with the soil. Specific gravity 0.7499; weight of cubic foot, 21.20 kilograms or 46.73 pounds.
Winter buds: Light chestnut brown, ovate, acute, one-fourth to one-half of an inch long.
Leaves: Alternate, 13 to 23 cm (5 to 9 in) long, 8 to 11 cm (3 to 4+1⁄2 in) wide, obovate to oblong-lanceolate, wedge-shaped or rounded at base, coarsely crenately toothed, teeth rounded or acute, apex rounded or acute. They come out of the bud convolute, yellow green or bronze, shining above, very pubescent below. When full grown are thick, firm, dark yellow green, somewhat shining above, pale green and pubescent below; midribs stout, yellow, primary veins conspicuous. In autumn they turn a dull yellow soon changing to a yellow brown. Petioles stout or slender, short. Stipules linear to lanceolate, caducous.
Flowers: May, when leaves are one-third grown. Staminate flowers are borne in hairy catkins (aments) two to three inches long; calyx pale yellow, hairy, deeply seven to nine-lobed; stamens 7 to 9; anthers bright yellow. Pistillate flowers in short spikes; peduncles green, stout, hairy; involucral scales hairy; stigmas short, bright red.
Acorns: Annual, singly or in pairs; nut oval, rounded or acute at apex, bright chestnut brown, shining, one and a quarter to one and one-half inches in length; cup, cup-shaped or turbinate, usually enclosing one-half or one-third of the nut, thin, light brown and downy within, reddish brown and rough outside, tuberculate near the base. Scales small, much crowded toward the rim sometimes making a fringe. Kernel white, sweetish.
The acorns of the chestnut oak are 1.5–3 cm (1⁄2–1+1⁄4 in) long and 1–2 cm (3⁄8–3⁄4 in) broad, among the largest of Native American oaks, surpassed in size only by the bur oak and possibly swamp chestnut oak.


Extensive confusion between the chestnut oak (Quercus montana) and the swamp chestnut oak (Quercus michauxii) has occurred, and some botanists have considered them to be the same species in the past.
The name Quercus prinus was long used by many botanists and foresters for either the chestnut oak or the swamp chestnut oak, with the former otherwise called Q. montana or the latter otherwise called Q. michauxii. The application of the name Q. montana to the chestnut oak is now accepted, since Q. prinus is of uncertain position, unassignable to either species.
The Latin specific epithet montana refers to mountains or coming from mountains which probably refers to the tree's habitat and its ability to grow on rocks.


This species is a predominant ridge-top tree in eastern North American hardwood forests. Young chestnut oaks are easily capable of reproducing from stump sprouts if cut. A significant amount of chestnut oaks in the Appalachians are trees that regrew from stump sprouts after being logged. It is a long-lived tree, with high-quality timber when well-formed. The acorns of the chestnut oak are a valuable wildlife food.


Chestnut oak trees are generally not the best timber trees because they are usually branched low and not very straight, but when they grow in better conditions, they are valuable for timber, which is marketed as 'mixed white oak'. The bark of chestnut oak has a high tannin content and prior to the 20th century was heavily used in the leather tanning industry, but the wood was usually discarded since it was considered inferior to that of Q. alba. By the late 19th century, as the population of mature white oaks in the eastern US was dwindling, loggers began exploiting chestnut oak wood more heavily. It serves many of the same applications as white oak wood and as it is fairly rot-proof, has also been used for fencing, railroad ties, and other uses where the wood comes into contact with soil. Due to a relatively high density (21 kg or 47 lb per cu. ft), chestnut oak makes excellent firewood.
The acorns can be eaten by humans but, if bitter, may need to have the tannins leached.


Quercus muehlenbergii, the chinquapin or chinkapin oak, is a deciduous species of tree in the white oak group (Quercus sect. Quercus). The species was often called Quercus acuminata in older literature. Quercus muehlenbergii (often misspelled as muhlenbergii) 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.


Chinkapin oak is monoecious in flowering habit; flowers emerge in April to late May or early June. The staminate flowers are borne in catkins that develop from the leaf axils of the previous year, and the pistillate flowers develop from the axils of the current year's leaves. The fruit, an acorn or nut, is borne singly or in pairs, matures in one year, and ripens in September or October. About half of the acorn is enclosed in a thin cup and is chestnut brown to nearly black.
Chinkapin oak is closely related to the smaller but generally similar dwarf chinkapin oak (Quercus prinoides). Chinkapin oak is usually a tree, but occasionally shrubby, while dwarf chinkapin oak is a low-growing, clone-forming shrub. The two species generally occur in different habitats: chinquapin oak is typically found on calcareous soils and rocky slopes, while dwarf chinkapin oak is usually found on acidic substrates, primarily sand or sandy soils, and also dry shales.
Chinkapin oak is also sometimes confused with the related chestnut oak (Quercus montana), which it closely resembles. However, unlike the pointed teeth on the leaves of the chinkapin oak, chestnut oak leaves generally have rounded teeth. The two species have contrasting kinds of bark: chinkapin oak has a gray, flaky bark very similar to that of white oak (Q. alba) but with a more yellow-brown cast to it (hence the occasional name yellow oak for this species), while chestnut oak has dark, solid, deeply ridged bark. The chinkapin oak also has smaller acorns than the chestnut oak or another similar species, the swamp chestnut oak (Q. michauxii), which have some of the largest acorns of any oaks.
Key characteristics of Quercus muehlenbergii include:
Leaf base is typically rounded
Veins and sinuses are regular
Acorns with no stalks or with short stalks less than 8 mm long. The acorns turn chestnut brown in the fall
The leaves have sharp teeth but no bristles, as a member of the white oak subgenus of Quercus


Q. muehlenbergii is generally regarded as a distinct species from the similar-appearing chestnut oak (Q. montana). The tree's scientific name honors Gotthilf Heinrich Ernst Muhlenberg (1753–1815), a Lutheran pastor and amateur botanist in Pennsylvania. In publishing the name Quercus mühlenbergii, German-American botanist George Engelmann mistakenly used an umlaut in spelling Muhlenberg's name, even though Pennsylvania-born Muhlenberg himself did not use an umlaut in his name. Under the modern rules of botanical nomenclature, umlauts are transliterated, with ü becoming ue, hence Engelmann's Quercus mühlenbergii is now presented as Quercus muehlenbergii. In lack of evidence that Engelmann's use of the umlaut was an unintended error, and hence correctable, the muehlenbergii spelling is considered correct, although the more appropriate orthographic variant Quercus muhlenbergii is often seen.
The low-growing, cloning Q. prinoides (dwarf chinkapin oak) is similar to Q. muehlenbergii and has been confused with it in the past, but is now generally accepted as a distinct species. If the two are considered to be conspecific, the earlier-published name Quercus prinoides has priority over Q. muehlenbergii, and the larger chinkapin oak can then be classified as Quercus prinoides var. acuminata, with the dwarf chinkapin oak being Quercus prinoides var. prinoides. Q. prinoides was named and described by the German botanist Karl (Carl) Ludwig Willdenow in 1801, in a German journal article by Muhlenberg.


Chinkapin oak is generally found on well-drained upland soils derived from limestone or where limestone outcrops occur. Occasionally it is found on well-drained limestone soils along streams. Chinkapin oak is generally found on soils that are weakly acid (pH about 6.5) to alkaline (above pH 7.0). It grows on both northerly and southerly aspects but is more common on the warmer southerly aspects. It is absent or rare at high elevations in the Appalachians.


It is rarely a predominant tree, but it grows in association with many other species. It is a component of the forest cover type White Oak-Black Oak-Northern Red Oak (Society of American Foresters Type 52) and the Post Oak-Blackjack Oak (Type 40) (2).
It grows in association with white oak (Quercus alba), black oak (Q. velutina), northern red oak (Q. rubra), scarlet oak (Q. coccinea), sugar maple (Acer saccharum), red maple (A. rubrum), hickories (Carya spp.), black cherry (Prunus serotina), cucumbertree (Magnolia acuminata), white ash (Fraxinus americana), American basswood (Tilia americana), black walnut (Juglans nigra), butternut (J. cinerea), and yellow-poplar (Liriodendron tulipifera). American beech (Fagus grandifolia), shortleaf pine (Pinus echinata), pitch pine (P. rigida), Virginia pine (P. virginiana), Ozark chinkapin (Castanea ozarkensis), eastern redcedar (Juniperus virginiana), bluejack oak (Quercus incana), southern red oak (Q. falcata), blackgum (Nyssa sylvatica), and winged elm (Ulmus alata) also grow in association with chinkapin oak. In the Missouri Ozarks a redcedar-chinkapin oak association has been described.
The most common small tree and shrub species found in association with chinkapin oak include flowering dogwood (Cornus florida), sassafras (Sassafras albidum), sourwood (Oxydendrum arboreum), eastern hophornbeam (Ostrya virginiana), Vaccinium spp., Viburnum spp., hawthorns (Crataegus spp.), and sumacs (Rhus spp.). The most common woody vines are wild grape (Vitis spp.) and greenbrier (Smilax spp.).


Chinkapin oak is classified as intolerant of shade. It withstands moderate shading when young but becomes more intolerant of shade with age. It is regarded as a climax species on dry, drought prone soils, especially those of limestone origin. On more moist sites it is subclimax to climax. It is often found as a component of the climax vegetation in stands on mesic sites with limestone soils. However, many oak-hickory stands on moist sites that contain chinkapin oak are succeeded by a climax forest including beech, maple, and ash.


Severe wildfire kills chinkapin oak saplings and small pole-size trees, but these often resprout. However, fire scars serve as entry points for decay-causing fungi, and the resulting decay can cause serious losses.
Oak wilt (Bretziella fagacearum), a vascular disease, attacks chinkapin oak and usually kills the tree within two to four years. Other diseases that attack chinkapin oak include the cankers Strumella coryneoidea and Nectria galligena, shoestring root rot (Armillarea mellea), anthracnose (Gnomonia veneta), and leaf blister (Taphrina spp.).
The most serious defoliating insects that attack chinkapin oak are the gypsy moth (Lymantria dispar), the orangestriped oakworm (Anisota senatoria), and the variable oakleaf caterpillar (Heterocampa manteo). Insects that bore into the bole and seriously degrade the products cut from infested trees include the carpenterworm (Prionoyxstus robiniae), little carpenterworm (P. macmurtrei), white oak borer (Goes tigrinus), Columbian timber beetle (Corthylus columbianus), oak timberworm (Arrhenodes minutus), and twolined chestnut borer (Agrilus bilineatus). The acorn weevils (Curculio spp.), larvae of moths (Valentinia glandulella and Melissopus latiferreanus), and gall forming cynipids (Callirhytis spp.) feed on the acorns.


Like that of other white oak species, the wood of the chinkapin oak (Q. muehlenbergii) is a durable hardwood prized for many types of construction.
The chinquapin oak is especially known for its sweet and palatable acorns. Indeed, the nuts contained inside of the thin shell are among the sweetest of any oak, with an excellent taste even when eaten raw, providing an excellent source of food for both wildlife and people. The acorns are eaten by squirrels, mice, voles, chipmunks, deer, turkey, and other birds.


Quercus nigra, the water oak, is an oak in the red oak group (Quercus sect. Lobatae), 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 meters (1,480 feet) in elevation.
Other names include spotted oak, duck oak, punk oak, orange oak, and possum oak.


Quercus nigra is a medium-sized deciduous tree, growing to 30 meters (98 feet) tall with a trunk up to 1 m (3 ft 3 in) in diameter. Young trees have a smooth, brown bark that becomes gray-black with rough scaly ridges as the tree matures. The leaves are alternate, simple and tardily deciduous, remaining on the tree until mid-winter; they are 3–12 centimeters (1+1⁄4–4+3⁄4 inches) long and 2–6 cm (3⁄4–2+1⁄4 in) broad, variable in shape, most commonly shaped like a spatula being broad and rounded at the top and narrow and wedged at the base. The margins vary, usually being smooth to shallowly lobed, with a bristle at the apex and lobe tips. The tree is easy to identify by the leaves, which have a lobe that looks as if a drop of water is hanging from the end of the leaf. The top of each leaf is a dull green to bluish green and the bottom is a paler bluish-green. On the bottom portion of the leaves, rusty colored hairs run along the veins. The acorns are arranged singly or in pairs, 10–14 millimeters (3⁄8–1⁄2 in) long and broad, with a shallow cupule; they mature about 18 months after pollination in autumn of the second year.


Water oak serves the same ecological role as weeping willow and other wetland trees. It is adapted to wet, swampy areas, such as along ponds and stream banks, but can also tolerate well-drained sites and even heavy, compacted soils. It grows in sandy soils, red clays, and old fields to the borders of swamps, streams, to bottomlands. Due to its ability to grow and reproduce quickly, the water oak is often the most abundant species in a stand of trees. The tree is relatively short-lived compared to other oaks and may live only 60 to 80 years. It does not compete well and does not tolerate even light shade. Water oak is frequently used to restore bottomland hardwood forests on land that was previously cleared for agriculture or pine plantations. Minimum age for flowering and fruiting is 20 years and the tree produces heavy crops of acorns nearly every year. Water oak is not recommended as an ornamental due to being short-lived, disease-prone, and extremely messy.
Hybrids of water oak are known with southern red oak (Quercus falcata), bluejack oak (Quercus incana), turkey oak (Quercus laevis), blackjack oak (Quercus marilandica), willow oak (Quercus phellos), Shumard oak (Quercus shumardii), and black oak (Quercus velutina).
Water oak acorns are an important food for white-tailed deer, eastern gray squirrel, raccoon, wild turkey, mallard, wood duck, and bobwhite quail. In winter, deer will browse the buds and young twigs.


Water oak has been used for timber and for fuel by people in the southern states since the 17th century. The wood is generally sold as "red oak", mixed with the wood from other red oaks.


Quercus palustris, the pin oak or swamp Spanish oak, is a tree in the red oak section (Quercus sect. Lobatae) of the genus Quercus. Pin oak is one of the most commonly used landscaping oaks in its native range due to its ease of transplant, relatively fast growth, and pollution tolerance.


Pin oak is a medium-sized deciduous tree growing to 18–22 metres (59–72 feet) tall, with a trunk up to 1 m (3+1⁄2 ft) in diameter. It has an 8–14 m (26–46 ft) spread. A 10-year-old tree grown in full sun will be about 8 m (26 ft) tall. Young trees have a straight, columnar trunk with smooth bark and a pyramidal canopy.
By the time the tree is 40 years old, it develops more rough bark with a loose, spreading canopy. This canopy is considered one of the most distinctive features of the pin oak: the upper branches point upwards, the middle branches are at right angles to the trunk, and the lower branches droop downwards.
The leaves are 5–16 centimetres (2–6+1⁄4 inches) long and 5–12 cm (2–4+3⁄4 in) broad, lobed, with five or seven lobes. Each lobe has five to seven bristle-tipped teeth. The sinuses are typically U-shaped and extremely deep cut. In fact, roughly the same amount of sinus area exists as actual leaf area. The leaf is mostly hairless, except for a very characteristic tuft of pale orange-brown down on the lower surface where each lobe vein joins the central vein. Overall autumn leaf coloration is generally bronze, though individual leaves may be red for a time, and is not considered particularly distinctive. The acorns, borne in a shallow, thin cap, are hemispherical, 10–16 millimetres (13⁄32–5⁄8 in) long and 9–15 mm (11⁄32–19⁄32 in) broad, green maturing pale brown about 18 months after pollination. Unless processed using traditional methods, the acorn is unpalatable because the kernel is very bitter.
In its natural environment pin oak is a relatively short-lived, fast-growing pioneer or riparian species with a lifespan of approximately 120 years against many oaks which can live several centuries. Despite this there are many examples of pin oak that exceed this lifespan. It develops a shallow, fibrous root system, unlike many oaks, which have a strong, deep taproot when young.
A characteristic shared by a few other oak species, and also some beeches and hornbeams, is the retention of leaves through the winter on juvenile trees, a natural phenomenon referred to as marcescence. Young trees under 6 m (20 ft) are often covered with leaves year-round, though the leaves die in the fall, remaining attached to the shoots until the new leaves appear in the spring. As with many other oak species, dead pin oak branches  stay on the tree for many years.


Like all oaks, flowering and leaf-out occur in late spring when all frost danger has passed. The flowers are monoecious catkins which, being self-incompatible, require the presence of another oak for pollination. Any species in the red oak group can serve as a pollinator, but in pin oak's natural range, this will usually be northern red oak or scarlet oak. Interspecies hybridization occurs freely. The acorns require two growing seasons to develop.


The Latin specific epithet palustris means "of marshland" or "of swamps", referring to its natural habitat.
The common name "pin oak" is possibly due to the many small, slender twigs, but may also be from the historical use of the hard wood for pins in wooden building construction.


Q. palustris is mainly distributed in the eastern and central United States from Connecticut west to eastern Kansas, and south to Georgia, west to eastern Oklahoma and Kansas. It is also native in the extreme south of Ontario, Canada.
The pin oak is also well adapted to life in Australia (where it has been introduced), and is quite widespread across the Australian continent, especially in the cooler southern States such as Victoria and New South Wales. It is also well adapted to life in South Africa and Argentina, especially in the Río de la Plata region.
It is naturally a wetland tree, confined to acidic soils, and does not tolerate limestone or sandy Florida soil, and grows at low altitudes from sea level up to 350 m (1,148 ft).
It grows primarily on level or nearly level, poorly drained, alluvial floodplain and river-bottom soils with high clay content. They are usually found on sites that flood intermittently during the dormant season, but do not ordinarily flood during the growing season. They do not grow on the lowest, most poorly drained sites that may be covered with standing water through much of the growing season. However, they do grow extensively on poorly drained upland "pin oak flats" on the glacial till plains of southwestern Ohio, southern Illinois and Indiana, and northern Missouri. The level topography and presence of a claypan in the soil of these areas cause these sites to be excessively wet in winter and spring.


Pin oak is a major species in only one forest cover type, pin oak–sweetgum, which is found on bottom lands and some upland sites throughout the central portion of the pin oak range. Pin oak and sweetgum (Liquidambar styraciflua) vary in their relative proportions in this cover type. Large areas of almost pure pin oak occur on the "pin oak flats" of the upland glacial till plains or in the bottom lands of the lower Ohio and central Mississippi River valleys. Associated species in this forest type include red maple (Acer rubrum), American elm (Ulmus americana), black tupelo (Nyssa sylvatica), swamp white oak (Quercus bicolor), willow oak (Quercus phellos), overcup oak (Quercus lyrata), bur oak (Quercus macrocarpa), green ash (Fraxinus pennsylvanica), Nuttall's oak (Quercus texana), swamp chestnut oak (Quercus michauxii), and shellbark (Carya laciniosa) and shagbark (Carya ovata) hickories.
Pin oak is an associated species in silver maple–American elm forests in the bottom lands along the Ohio, Wabash, Mississippi, and Missouri Rivers. A variant of this type, silver maple–American elm–pin oak–sweetgum, is found along major streams in southern Illinois and Indiana.
Pin oak also occurs in black ash–American elm–red maple forests in poorly drained bottom lands in northern Ohio and Indiana along with silver maple (Acer saccharinum), swamp white oak, sycamore (Platanus occidentalis), black tupelo, and eastern cottonwood (Populus deltoides).


Pin oak is classed as intolerant of shade. It is less tolerant than elm, boxelder (Acer negundo), sweetgum, hackberry (Celtis occidentalis), and ash, but is more tolerant than eastern cottonwood and black willow. Pin oak usually grows in even-aged stands of dominant and co-dominant trees. Intermediate and suppressed trees in such stands usually die within a few years of being overtopped. Single pin oaks in mixed stands usually are dominants. Pin oak is considered a subclimax species. It persists on heavy, wet soils because it produces an abundance of acorns which, if released, grow faster on these sites than most of its competitors.
Pin oaks are also classified as allelopathic, meaning they crowd out or otherwise successfully compete with understory vegetation to survive.


Although pin oak is very tolerant of dormant-season flooding, it is much less tolerant of growing-season flooding. Trees may be injured or killed by intermittent growing-season flooding over several successive years. The trees can usually survive one growing season of continuous flooding, but will be killed by continuous flooding over 2 or 3 consecutive years. Pin oak is rated as "intermediately tolerant" to growing-season flooding. Also, since the bark of pin oak is relatively thin, the species is especially susceptible to damage by fire and decay associated with fire wounds.


Due to similarity in leaf shape, the pin oak is often confused with scarlet oak and black oak, and occasionally, red oak. However, it can be distinguished by its distinctive dead branches on the lower trunk ("pins"), and its uniquely shaped crown. The sinuses on pin oak leaves are also deeply cut, often covering just as much area as the leaf itself.
The pin oak is the only known food plant of Bucculatrix domicola caterpillars.


In its native range, pin oak is the most commonly used landscaping oak along with northern red oak due to its ease of transplant, relatively fast growth, and pollution tolerance. However, as it is naturally adapted to moist, acidic soils, it may develop a condition known as iron chlorosis on less suitable locations, causing the tree to shed leaves during the growing season and rot from the top down. Mature pin oaks are often too big to treat and this nutrient deficiency on alkaline soil may eventually kill them. The drooping lower branches can also be a problem, interfering with access for traffic and pedestrians.
It is also cultivated in parks and large gardens in the United Kingdom, and has gained the Royal Horticultural Society's Award of Garden Merit.
The wood is generally marketed as red oak, but is of significantly inferior quality, being somewhat weaker, often with many small knots. The wood is hard and heavy and is used in general construction and for firewood. The bark was used by some Native American tribes to make a drink for treatment of intestinal pain.


Quercus phellos, the willow oak, is a North American species of a deciduous tree in the red oak group of oaks. It is native to the south-central and eastern United States.


It is a medium-sized tree growing to 20–30 meters (65–100 feet) tall (exceptionally to 39 m, 128 ft), with a trunk up to 1–1.5 m (3+1⁄2–5 ft) in diameter (exceptionally 2 m or 6+1⁄2 ft). It is distinguished from most other oaks by its leaves, which are shaped like willow leaves, 5–12 centimeters (2–4+3⁄4 inches) long and 1–2.5 cm (3⁄8–1 in) broad with an entire (untoothed and unlobed) margin; they are bright green above, paler beneath, usually hairless but sometimes downy beneath. The fruit is an acorn, 8–12 millimeters (5⁄16–15⁄32 in) long, and almost as wide as long, with a shallow cup; it is one of the most prolific producers of acorns. The tree starts acorn production around 15 years of age, earlier than many oak species.
Willow oaks can grow moderately fast (height growth up to 60 cm or 2 ft a year), and tend to be conic to oblong when young, rounding out and gaining girth at maturity (i.e. more than 50 years).


The species is most common in the American south and eastern states. It can be found from Long Island Sound south to northern Florida, and west to southernmost Illinois, Missouri, Oklahoma, and eastern Texas. Its natural range extends into southeastern Pennsylvania and southern New Jersey. It has also historically been recorded as occurring in Lancaster, Bucks, Chester, Delaware, and Philadelphia counties, chiefly on wet sites, occasionally in drier, upland ones. Much of that area has been built over and developed since World War II, and the tree is now classified as endangered in the state.
It is most commonly found growing on lowland floodplains, often along streams, but rarely also in uplands with poor drainage, up to 400 m (1,300 ft) in altitude.


Economic uses are primarily as an ornamental tree and the wood for pulp and paper production, but also for lumber; it is often marketed as "red oak" wood.
The willow oak is one of the most popular trees for horticultural planting, due to its rapid growth, hardiness, balance between axial and radial dominance, ability to withstand both sun and shade, light green leaf color and full crown. Despite being heavily used in landscaping in the Southern US (such as Washington, D.C., Charlotte, North Carolina and Atlanta, Georgia) around malls, along roads, etc., the trees tend to grow larger than planners expect, which often leads to cracked sidewalks.


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 robur is a large deciduous tree, with circumference of grand oaks from 4 metres (13 feet) to an exceptional 12 m (39 ft). The Majesty Oak with a circumference of 12.2 m (40 ft) is the thickest tree in Great Britain, and the Kaive Oak in Latvia with a circumference of 10.2 m (33 ft) is the thickest tree in Northern Europe. The largest historical oak was known as the Imperial Oak from Bosnia and Herzegovina. This specimen was recorded at 17.5 m in circumference at breast height and estimated at over 150 m³ in total volume. It collapsed in 1998. The species has lobed and nearly sessile (very short-stalked) leaves 7–14 centimetres (3–5+1⁄2 inches) long. Flowering takes place in mid spring, and the fruit, called acorns, ripen by mid autumn. The acorns are 2–2.5 cm (3⁄4–1 in) long, pedunculate (having a peduncle or acorn-stalk, 3–7 cm (1–3 in) long) with one to four acorns on each peduncle.
It is a long-lived tree, with a large wide spreading crown of rugged branches. While it may naturally live to an age of a few centuries, many of the oldest trees are pollarded or coppiced, both pruning techniques that extend the tree's potential lifespan, if not its health. Two individuals of notable longevity are the Stelmužė Oak in Lithuania and the Granit Oak in Bulgaria, which are believed to be more than 1500 years old, possibly making them the oldest oaks in Europe; another specimen, called the 'Kongeegen' ('Kings Oak'), estimated to be about 1,200 years old, grows in Jaegerspris, Denmark. Yet another can be found in Kvilleken, Sweden, that is over 1000 years old and 14 m (46 ft) around. Of maiden (not pollarded) specimens, one of the oldest is the great oak of Ivenack, Germany. Tree-ring research of this tree and other oaks nearby gives an estimated age of 700 to 800 years. Also the Bowthorpe Oak in Lincolnshire, England is estimated to be 1,000 years old, making it the oldest in the UK, although there is Knightwood Oak in the New Forest that is also said to be as old. The highest density of Q. robur with a circumference of 4 m (13 ft) and more is in Latvia.


Grandinin/roburin E, castalagin/vescalagin, gallic acid, monogalloyl glucose (glucogallin) and valoneic acid dilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, rhamnose, quercitrin and ellagic acid are phenolic compounds found in Q. robur. The heartwood contains triterpene saponins.


Quercus robur (Latin quercus, "oak" + robur "strength, hard timber") is the type species of the genus (the species by which the oak genus Quercus is defined), and a member of the white oak section (Quercus section Quercus). The populations in Italy, southeast Europe, and Asia Minor and the Caucasus are sometimes treated as separate species, Q. brutia Tenore, Q. pedunculiflora K. Koch and Q. haas Kotschy respectively.
A close relative is the sessile oak (Q. petraea), which shares much of its range. Q. robur is distinguished from this species by its leaves having only a very short stalk (petiole) 3–8 millimetres (1⁄8–5⁄16 in) long, and by its pedunculate (stalked) acorns. The two often hybridise in the wild, the hybrid being known as Quercus × rosacea.
Quercus robur should not be confused with Q. rubra, the red oak, which is a native of North America and only distantly related.


Quercus robur is very tolerant to soil conditions and the continental climate but it prefers fertile and well-watered soils. Mature trees tolerate flooding.
Within its native range, Q. robur is valued for its importance to insects and other wildlife. Numerous insects live on the leaves, buds, and in the acorns. Q. robur supports the highest biodiversity of insect herbivores of any British plant (>400 spp) and the quantity of caterpiller species increases with their age. Blue and great tits time their egg hatching to the leaves opening.
The acorns form a valuable food resource for several small mammals and some birds, notably Eurasian jays Garrulus glandarius. Jays were overwhelmingly the primary propagators of oaks before humans began planting them commercially (and still remain the principal propagators for wild oaks), because of their habit of taking acorns from the umbra of its parent tree and burying them undamaged elsewhere. Mammals, notably squirrels who tend to hoard acorns and other nuts, usually leave them too abused to grow in the action of moving or storing them.


A number of cultivars are grown in gardens and parks and in arboreta and botanical gardens. The most common cultivar is Quercus robur 'Fastigiata', and is the exception among Q. robur cultivars that are generally smaller than the standard tree, growing to between 10 and 15 m (35 and 50 ft) and exhibit unusual leaf or crown shape characteristics.
In Australia
English oak is one of the most common park trees in south-eastern Australia, noted for its vigorous, luxuriant growth. In Australia, it grows very quickly to a tree of 20 m (66 ft) tall by up to 20 m (66 ft) broad, with a low-branching canopy. Its trunk and secondary branches are very thick and solid and covered with deep-fissured blackish-grey bark.
The largest example in Australia is in Donnybrook, Western Australia.


Quercus robur 'Fastigiata' ("cypress oak"), probably the most common cultivated form, it grows to a large imposing tree with a narrow columnar habit. The fastigiate oak was originally propagated from an upright tree that was found in central Europe.
Quercus robur 'Concordia' ("golden oak"), a small very slow-growing tree, eventually reaching 10 m (33 ft), with bright golden-yellow leaves throughout spring and summer.  It was originally raised in Van Geert's nursery at Ghent in 1843.
Quercus robur 'Pendula' ("weeping oak"), a small to medium-sized tree with pendulous branches, reaching up to 15 m.
Quercus robur 'Purpurea' is another cultivar growing to 10 m, but with purple-coloured leaves.
Quercus robur 'Filicifolia' ("cut-leaved oak") is a cultivar where the leaf is pinnately divided into fine forward pointing segments.


Acute oak decline
Powdery mildew caused by Erysiphe alphitoides
Sudden oak death


Quercus robur is planted for forestry, and produces a long-lasting and durable heartwood, much in demand for interior and furniture work. The wood of Q. robur is identified by a close examination of a cross-section perpendicular to fibres. The wood is characterised by its distinct (often wide) dark and light brown growth rings. The earlywood displays a vast number of large vessels (around 0.5 mm or 1⁄64 inch in diameter). There are rays of thin (about 0.1 mm or 1⁄256 in) yellow or light brown lines running across the growth rings. The timber is around 720 kilograms (1,590 pounds) per cubic meter in density.


In Germany, the oak tree is used as a typical object and symbol in romanticism. It can be found in several paintings of Caspar David Friedrich and in "Of the life of a Good-For-Nothing" written by Joseph Freiherr von Eichendorff as a symbol of the state protecting every citizen. In those works the oak is shown in different situations, with leaves and flowers or dead without any of its previous beauty. Those conditions are mostly symbols for the conditions Germany is in or going through. Furthermore, the oak's stem is a symbol for Germany's strength and stability. Oak branches were displayed on the reverse of coins of the old Deutsche Mark currency (1 through 10 Pfennigs; the 50 Pfennigs coin showed a woman planting an oak seedling), and are now also displayed on the reverse of German-issue Euro currency coins (1 through 5 cents).


In England, the English oak has assumed the status of a national emblem. This has its origins in the oak tree at Boscobel House, where the future King Charles II hid from his Parliamentarian pursuers in 1650 during the English Civil War; the tree has since been known as the Royal Oak. This event was celebrated nationally on 29 May as Oak Apple Day, which is continued to this day in some communities. 'The Royal Oak' is the third most popular pub name in Britain (with 541 counted in 2007) and has been the name of eight major Royal Navy warships. The naval associations are strengthened by the fact that oak was the main construction material for sailing warships. The Royal Navy was often described as 'The Wooden Walls of Old England' (a paraphrase of the Delphic Oracle) and the Navy’s official quick march is "Heart of Oak". In folklore, the Major Oak is where Robin Hood is purportedly to have taken shelter. Furthermore, the oak is the most common woodland tree in England. An oak tree has been depicted on the reverse of the pound coin (the 1987 and 1992 issues) and a sprig of oak leaves and acorns is the emblem of the National Trust.


The genome of Q. robur has been completely sequenced (GenOak project); a first version was published in 2016. It comprises 12 chromosomes pairs, about 26,000 genes and 750 million bp. This is roughly a quarter of the size of the human genome, which has about 3 billion base pairs.


Quercus rubra, the northern red oak, is an oak tree in the red oak group (Quercus section Lobatae). 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.


In many forests, this deciduous tree grows straight and tall, to 28 metres (92 feet), exceptionally to 43 m (141 ft) tall, with a trunk of up to 50–100 centimetres (20–39 inches) in diameter. Open-grown trees do not get as tall, but can develop a stouter trunk, up to 2 m (6+1⁄2 ft) in diameter. It has stout branches growing at right angles to the stem, forming a narrow round-topped head.
Under optimal conditions and full sun, northern red oak is fast growing and a 10-year-old tree can be 5–6 m (16–20 ft) tall. Trees may live up to 400 years and a living example of 326 years was noted in 2001.
Northern red oak is easy to recognize by its bark, which features ridges that appear to have shiny stripes down the center. A few other oaks have bark with this kind of appearance in the upper tree, but the northern red oak is the only tree with the striping all the way down the trunk.
As with most other deciduous oaks, leafout takes place in spring when day length has reached 13 hours—it is tied entirely to photoperiod and will take place regardless of air temperature. As a consequence (see below), in cooler regions, northern red oaks often lose their flowers to late spring frosts, resulting in no seed crop for the year. The catkins and leaves emerge at the same time. The acorns develop on the tree for two growing seasons and are released from the tree in early October, and leaf drop begins when day length falls under 11 hours. The timing of leafout and leaf drop can vary by as much as three weeks in the northern and southern US. Seedlings emerge in spring when soil temperatures reach 21 °C (70 °F).
Bark: Dark reddish gray brown, with broad, thin, rounded ridges, scaly. On young trees and large stems, smooth and light gray. Rich in tannin. Branchlets slender, at first bright green, shining, then dark red, finally dark brown. Bark is brownish gray, becoming dark brown on old trees.
Wood: Pale reddish brown, sapwood darker, heavy, hard, strong, coarse-grained. Cracks in drying, but when carefully treated could be successfully used for furniture. Also used in construction and for interior finish of houses. Sp. gr., 0.6621; weight of cu. ft., 41.25 lbs.
Winter buds: Dark chestnut brown (reddish brown), ovate, acute, generally 6 mm (1⁄4 in) long
Leaves and acorns: Alternate, seven to nine-lobed, oblong-ovate to oblong, five to ten inches long, four to six inches broad; seven to eleven lobes tapering gradually from broad bases, acute, and usually repandly dentate and terminating with long bristle-pointed teeth; the second pair of lobes from apex are largest; midrib and primary veins conspicuous. Lobes are often less deeply cut than most other oaks of the red oak group. Leaves emerge from the bud convolute, pink, covered with soft silky down above, coated with thick white tomentum below. When full grown are dark green and smooth, sometimes shining above, yellow green, smooth or hairy on the axils of the veins below. In autumn they turn a rich red, sometimes brown. Often the petiole and midvein are a rich red color in midsummer and early autumn, though this is not true of all red oaks. The acorns mature in about 18 months after pollination; solitary or in pairs, sessile or stalked; nut oblong-ovoid with broad flat base, full, with acute apex, one half to one and one-fourth of an inch long, first green, maturing nut-brown; cup, saucer-shaped and shallow, 2 cm (3⁄4 in) wide, usually covering only the base, sometimes one-fourth of the nut, thick, shallow, reddish brown, somewhat downy within, covered with thin imbricated reddish brown scales. Its kernel is white and very bitter.
Red oak acorns, unlike the white oak group, display epigeal dormancy and will not germinate without a minimum of three months' exposure to temperatures below 4 °C (40 °F). They also take two years of growing on the tree before development is completed.


The species grows from the north end of the Great Lakes, east to Nova Scotia, south as far as Georgia, Mississippi, Alabama, and Louisiana, and west to Oklahoma, Kansas, Nebraska, and Minnesota.
It grows rapidly and is tolerant of many soils and varied situations, although it prefers the glacial drift and well-drained borders of streams. In the southeastern United States, it is frequently a part of the canopy in an oak-heath forest, but generally not as important as some other oaks.
Northern red oak is the most common species of oak in the northeastern US after the closely related pin oak (Q. palustris). The red oak group as a whole are more abundant today than they were when European settlement of North America began as forest clearing and exploitation for lumber much reduced the population of the formerly dominant white oaks.


Over the last few decades, the northern red oak has dealt with several environmental factors, mainly disease, predation by insects, and limited opportunities for dispersal. These stresses have impacted the species' ability to proliferate in both the Northeast and Europe. The various environmental responses observed in Quercus rubra across several temperate environmental conditions have allowed for it to serve as a model organism for studying symbiotic relationships, dispersal, and habituation between tree species.


Canker pathogen, Diplodia corticola, has become a major pathogen to the species over the last decade, causing leaf browning, bark cracking and bleeding, and high rates of tree mortality across the northeastern United States. The northern red oak is also characterized as one of the most susceptible species to plant fungi Phytophthora cinnamomi and Phytophthora ramorum, which have caused severe, red-black cankers in the trunk region of the species. Both P. cinnamomi and P. ramorum grow under warmer temperature conditions; as a result, northern red oak trees found in California, France, and northern Spain all have higher incidences of fungal infection.  Oak Wilt caused by the fungus Ceratocystis fagacearum is a major pathogen found in eastern North America that can kill trees quickly.


Northern red oak seedlings have been known to have a high mortality rate in northeast regions prone to spring freeze, particularly in Massachusetts. Acorns produced by oaks in this region are typically smaller in size as an adaptation to frost produced in high latitudes; however, the resulting smaller seedlings have produced limited opportunities for animal consumption and dispersal. Flooding along the continental United States has been shown to be a major issue for the northern red oak, in which decreased phloem transport and photosynthetic activity has been observed, but only after multiple days of flooding, indicating that the northern red oak has adapted moderate resistance to excess water exposure. The northern red oak has also developed tolerance mechanisms for heat stress, particularly observed in deciduous forests in the Southeastern United States, where, during summer heat waves, temperatures can exceed 40 °C (104 °F). The leaves of the northern red oak have been observed to have an acclimation to Rubisco activase activity that is directly correlated to acclimations with repeated exposure to heat waves. Consistent photosynthetic activity in the red oak has also been observed in the presence of high carbon dioxide levels that often occur as a result of elevated temperatures.


Northern red oak kernels have highly concentrated amounts of bitter-tasting tannin, a biochemical classified as a predator deterrent, which has limited appeal for consumption among animals. Despite this, the acorns are eaten by deer, squirrels and birds. In Europe, the acorns are consumed by several moth species, particularly Cydia fagiglandana and Cydia splendana, which increases their niche breadths and reduces their competition with Curculio weevils. Due to this, germination rates among the northern red oak acorns have decreased significantly and resulted in less seed dispersal by animals within Poland. In addition, limited opportunities for dispersal have become costly for the northern red oak in Europe. European animals known for dispersing tendencies, such as the European jay and wood mouse, have been found to be more attracted to local oak species.


Quercus rubra has effective ectomycorrhizal relationships that have been correlated with increased growth rates. Northern red oak trees have been shown to increase growth in the presence of various ascomycetes that coil at the base of the oak trunk. The fungi, which eventually proliferate at the stumps of deciduous trees, have been found to be host-specific to both Quercus rubra and Quercus montana and primarily promote growth upon infection.


It was introduced to Europe in the 1700s and has naturalized throughout most of western and central Europe.
Across western and central Europe, the northern red oak has become the fourth-most significant invasive species, colonizing several regions across Belgium, Germany, Northern Italy, Lithuania, Poland, Ukraine, European Russia, the Urals and Western Siberia). The northern red oak is primarily found on the edges of woodland reserves in Europe, where light availability, tannin concentration, and animal dispersal are the most necessary component for the species' longevity and survival. The high influx of the species in Europe is primarily based on its economic productivity as a fast-growing source of timber; however, it has been linked to lower percentages of trace elements and minerals found in the surrounding soil and reduced richness among native oak species such as Quercus robur.


The northern red oak is one of the most important oaks for timber production in North America. Quality red oak is of high value as lumber and veneer, while defective logs are used as firewood. Other related oaks are also cut and marketed as red oak, although their wood is not always of as high a quality. These include eastern black oak, scarlet oak, pin oak, Shumard oak, southern red oak and other species in the red oak group. Construction uses include flooring, veneer, interior trim, and furniture. It is also used for lumber, railroad ties, and fence posts.
Red oak wood grain is so open that smoke can be blown through it from end-grain to end-grain on a flat-sawn board. For this reason, it is subject to moisture infiltration and is unsuitable for outdoor uses such as boatbuilding or exterior trim.
The acorns can be collected in autumn, shelled, tied up in a cloth, and leached to remove bitterness. They can then be eaten whole or ground into meal.


Quercus rubra is grown in parks and large gardens as a specimen tree. It is not planted as often as the closely related pin oak as it develops a taproot and quickly becomes difficult to transplant, however modern growing pots have made starting seedlings with taproots easier than in the past.


It is the state tree of New Jersey and the provincial tree of Prince Edward Island.


Ashford Oak – A very large Northern Red Oak in Ashford, Connecticut. The tree has suffered falling limbs because of its great age. However, this tree is still a sight to behold; the trunk is 8 m (26 ft) in circumference and the root-knees are also particularly impressive. The oak is located on Giant Oak Lane off U.S. Highway 44. There are several other large oaks in the area.
Chase Creek Red Oak – This forest tree is located on a very rich steep slope in Anne Arundel County, Maryland. It is a high-stump coppice with three leads. It was the state champion oak in Maryland in 2002. The circumference at breast height is 6.7 m (22 ft 0 in), the height 41.5 m (136 ft 2 in) and the spread 29.9 m (98 ft 1 in)
Shera-Blair Red Oak – This majestic red oak tree is located on Shelby Street in the South Frankfort neighborhood in Franklin County, Kentucky, and is the largest red oak tree in the oldest neighborhood in Frankfort, Kentucky. It is in the backyard of a house built in 1914 by architect Arthur Raymond Smith, who at one time worked for D.X. Murphy & Bros., famed architects that designed the twin spires at Churchill Downs. The circumference at breast height is 6.4 m (21 ft 0 in), with the trunk reaching higher than 12 m (40 ft) before the branches begin and an estimated height of 40 m (130 ft).
Zhelevo – At over 250 years old, this tree is among the oldest in Toronto. The trunk has a circumference of 4.95 m (16 ft 3 in) and the canopy is over 24 m (79 ft) tall. The lot where the tree stands has been purchased by the City of Toronto to be turned into a public park.


Quercus shumardii, the Shumard oak, spotted oak, Schneck oak, Shumard red oak, or swamp red oak, is one of the largest of the oak species in the red oak group (Quercus section Lobatae). It is closely related to Quercus buckleyi (Texas red oak), Quercus texana (Nuttall's red oak), and Quercus gravesii (Chisos red oak).


Mature Shumard oaks typically reach heights of 25 to 35 metres (82 to 115 feet), trunk diameter is typically 60 to 100 centimetres (24 to 39 inches), and crown width typically reaches 12 to 18 m (39 to 59 ft) in width. Typical size varies according to region, with larger specimens occurring in the southern portions of its native range in the United States. Record Shumard oaks have been measured at up to 60 m (200 ft) tall, with crowns up to 27.5 m (90 ft) in width. Young specimens generally exhibit conic or ovate crowns, with the upper crown filling in as the tree reaches maturity. Trunks are relatively straight and vertical. Trunks may have deeply fluted buttresses near the ground. Shumard oak is typically found in lowland areas and is able to survive where the soils experience flooding for six weeks of the year.
The young bark of the Shumard oak is light gray, very smooth, and very reflective. Shumard oak bark darkens and develops ridges and furrows as it ages. Occasionally, white splotches are seen on the bark.
Shumard oak twigs terminate in a cluster of buds. The buds are lighter in color than the olive-green twigs. The young twig is highly reflective.
The leaves are arranged alternately and are broadly obovate with 5–9 lobes, each of which is terminated by bristle-tipped teeth. The leaves mature to between 10 and 21 cm (4 and 8 in) in length. The surfaces are glabrous, except for the tufted vein axils. They are dark green on the top, while their bottoms are a slightly lighter shade of green. The leaves turn brown to red in the fall and sometimes have hues of yellow mixed in. Fall colors are relatively late; specimens in central Texas may be at their most red in early December, while Florida specimens may not color substantially until February.
Shumard oaks bear relatively large acorns, which typically reach up to 3 cm (1 in) in diameter. Acorns take between 1.5 and 3 years to fully mature and may go unnoticed during their early stages of development.


Shumard oak is native to the Atlantic coastal plain primarily from North Carolina to northern Florida and west to central Texas; it is also found north in the Mississippi River Valley to central Oklahoma, eastern Kansas, Missouri, southern Illinois, Indiana, western and southern Ohio, Kentucky, and Tennessee. It is found locally north to southern Michigan, southern Pennsylvania, Maryland, western New York, and the extreme south of Ontario, Canada.
It is tolerant of wide ranges of pH levels in soil. It is drought-resistant, and prefers partial to full sunlight. Shumard oaks begin to bear seeds at a minimum of 25 years of age, and the optimum age for seed development is 50. They are known to have reached at least 480 years of age. The roots are intolerant to disturbance.


The acorns of the Shumard oak provide food for various songbirds, game birds such as wild turkey and quail, waterfowl, white-tailed deer, feral hogs, and various rodents such as squirrels. The leaves and twigs can also provide browse for white-tailed deer.
Oak wilt can attack all red oaks, including the Shumard oak. Other diseases that attack Shumard oaks are various fungi that can grow on the leaves, powdery mildew, canker diseases, and shoestring root.


Shumard oak is valued for commercial use and as a shade tree. With the Shumard Oak's ability to tolerate and thrive in a wide range of soil types, it is cultivated at least as far north as Ottawa, Ontario and southern Quebec, and as far south as Lake Worth Beach, Florida.
Shumard oak lumber is grouped with other red oak lumber for use in flooring, furniture, interior trim, decorative molding, paneling, and cabinetry. According to one guide, the lumber of Shumard oak is considered "mechanically superior" to that of other red oaks.


Quercus sinuata is a species of oak comprising two distinct varieties, Quercus sinuata var. breviloba and Quercus sinuata var. sinuata, occurring in southeast North America.


Quercus sinuata is a deciduous tree up to 20 metres (67 feet) tall. Leaves are narrow, with shallow rounded lobes. It tends to grow in wet habitats, such as on river bluffs, river bottoms, and flatwoods, and generally over basic substrates, such as mafic rocks, shells, or calcareous sediment.
There are two varieties, with morphologically intermediate forms sometimes occurring where their ranges overlap:
Quercus sinuata var. breviloba (Torr.) C.H.Mull. – Texas, Oklahoma, Mexico
Quercus sinuata var. sinuata – Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, Carolinas, Texas


Perhaps arising from the classification challenges posed by a lack of morphological consistency among individuals of the species, the common name bastard oak may refer to either var. sinuata or var. breviloba or to any of their intermediate forms. The common names Durand oak and  Durand white oak most often refer to Quercus sinuata var. sinuata. Other common names for Quercus sinuata var. sinuata include bastard white oak and bluff oak, but these names more often refer to Quercus austrina. Common names for Quercus sinuata var. breviloba are Bigelow oak, Bigelow's oak, shallow-lobed oak, white shin oak, scaly-bark oak, limestone Durand oak, and shortlobe oak. Other common names include scrub oak or shin oak, but these names may refer to a number of other low growing, clump forming oak species, subspecies or varieties. For clear differentiation in common reference, American Forests uses Durand Oak to mean Quercus sinuata var. sinuata and Bigelow oak to mean Quercus sinuata var. breviloba, a shrubby variety of Quercus sinuata distinguished in part by its habit of forming clonal colonies in parts of its range.


Quercus sinuata var. breviloba is native to central and north central Texas, south central and southwest Oklahoma, and to Coahuila, Nuevo León, and Tamaulipas in northern Mexico. Quercus sinuata var. sinuata is native to the south-central and southeastern United States from central Texas and southwestern Arkansas to the Carolinas. Their respective ranges intersect in the Hill Country of central Texas, where streams flowing through dry, brushy limestone hills create a mosaic of wet and well drained habitats.


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 areas on the edges of fields, tops of ridges also grows in poor soils, and is resistant to rot, fire, and drought. Interbreeding occurs among white oaks, thus many hybrid species combinations occur.
The species is native to the eastern and central United States, and found along the east coast from Massachusetts to Florida, and as far inland as Nebraska. It is identifiable by the rounded cross-like shape formed by the leaf lobes and hairy underside of the leaves.


Post oak is a relatively small tree, typically 10–15 metres (33–49 feet) tall and trunk 30–60 centimetres (12–24 inches) in diameter, though occasional specimens reach 30 m (98 ft) tall and 140 cm (55 in) in diameter. The leaves have a very distinctive shape, with three perpendicular terminal lobes, shaped much like a Maltese cross. They are leathery, and tomentose (densely short-hairy) beneath. The branching pattern of this tree often gives it a rugged appearance. The acorns are 1.5–2 cm (5⁄8–3⁄4 in) long, and are mature in their first summer.


Both Quercus stellata and Q. alba are in a section of Quercus called the white oaks. In the white oak section, Q. stellata is a sister taxon with Q. alba. Q. stellata is sold and distributed as white oak. One identifiable difference between the two trees is that Q. stellata is 'hairy' on the underside of the leaf.


The specific epithet stellata is Latin for "star"; it is named this because the trichome hairs on the bottom of  the leaves are stellate or star-shaped. Several variants of Q. stellata were named by American botanist Charles Sprague Sargent. The variety most recognised by the United States Forest Service is Q. stellata var. paludosa Sarg (delta post oak).


Varieties include:
var. margarettiae (Ashe) Sarg.
var. paludosa Sarg.
var. boyntonii (Beadle) Sarg.
var. anomala Sarg.
var. attenuata Sarg.
var. araniosa Sarg.
var. palmeri Sarg.
var. parviloba Sarg.
var. rufescens Sarg.


Q. stellata is found in Southeastern United States, in the coast states from Massachusetts, to Texas, and inland to Iowa. In Texas, the Post Oak Savannah extends down to, and ends in, far northwestern Atascosa county where a fairly dense population exists.  Normally found at the edge of a forest, it typically grows in dry, sandy areas, deficient of nutrients.


Q. stellata has the ability to survive fires by having thicker bark. It is useful for fire surveys where the tree rings are used to get a fire history of an area. A tree ring survey of 36 trees in Illinois provided a 226-year tree ring record that indicated that many Q. stellata persisted through annual fire return intervals of 1.44 fires/year for over 100 years.
It is used for food for deer, turkeys, squirrels, and other rodents, but because the nuts contain tannin, it is toxic to cattle.


Because of its ability to grow in dry sites, attractive crown, and strong horizontal branches, it is used in urban forestry. It is resistant to decay, so it is used for railroad ties, siding, planks, construction timbers, stair risers and treads, flooring, pulp, veneer, particle board, fuel, and its namesake fence posts. It is one of the most common types of wood used for Central Texas barbecue.


Quercus suber, commonly called the cork oak,  is a medium-sized, evergreen oak tree in the section Quercus sect. Cerris. It is the primary source of cork for wine bottle stoppers and other uses, such as cork flooring and as the cores of cricket balls.  It is native to southwest Europe and northwest Africa. In the Mediterranean basin the tree is an ancient species with fossil remnants dating back to the Tertiary period.
It endures drought and makes little demand on the soil quality. Cork oak forests are home to a multitude of animal and plant species. Since cork is increasingly being displaced by other materials as a bottle cap, these forests are at risk as part of the cultural landscape and animal species such as the Iberian lynx are threatened with extinction.


The cork oak grows as an evergreen tree, reaching an average height of 10 to 15 metres (33 to 49 feet) or in rare cases up to 25 m and a trunk diameter (DBH) of 50 to 90 centimetres (20 to 35 inches). It forms a dense and asymmetrical crown that starts at a height of 2–3 m (6+1⁄2–10 ft) and spreads widely in free-standing trees. The crown can be divided into several separate, rounded partial crowns.
The young twigs are densely hairy light gray or whitish. Older branches are strong and knotty. Older trees only form short shoots between 7 to 15 cm (3 to 6 in) in length.
The thick, longitudinally cracked cork layers of the gray-brown trunk bark are characteristic of the cork oak. The cambium of the smooth bark of young trees forms a cork layer very early on, which can be 3 to 5 cm (1+1⁄4 to 2 in) thick. The light and spongy cork fabric shows vertical cracks and is white on the outside and red to red-brown on the inside. After the cork has been harvested, the trunk appears reddish brown, but later it is significantly darker. The wood is ring-pored, has a brown heartwood and a light reddish sapwood. The cork oak develops a taproot that reaches a depth of 1 to 2 m (3+1⁄4 to 6+1⁄2 ft) and from which several meters long, horizontally running side roots extend. The trees can reach over 400 years old, and harvested specimens can be 150 to 200 years old.


The leathery leaves are alternate and are 2.5 to 10 cm (1 to 4 in) long and 1.2 to 6.5 cm (1⁄2 to 2+1⁄2 in) wide. The shape varies between round, oval and lanceolate-oval. The leaf blade has five to seven sharp teeth on both edges and a pointed vegetation cone (apex). The midrib stands out clearly on the underside of the leaf, the first-order lateral nerves usually lead to the teeth of the leaf margin. The upper side of the leaf is light green, the underside of the leaf whitish and densely hairy. There is no hair on young trees. The leaf stalks are 6 to 18 millimetres (1⁄4 to 3⁄4 in) long and are also hairy. At the base of the petiole are two narrow, lanceolate, 5 mm (1⁄4 in) long and bright red stipules that fall off in the first year. The new leaves appear in April and May, when older leaves are also shed. They usually stay on the tree for two to three years, less often only one year, the latter especially in severe environmental conditions and on the northern border of the distribution area. Extremely cold winters can also lead to complete defoliation.


The cork oak is single sexed (monoecious), with both female and male flowers on one specimen. The female flowers form upright inflorescences in the leaf axils of young branches. These are formed from a hairy axis 5 to 30 mm (1⁄4 to 1+1⁄4 in) long with two to five separate flowers. The female flowers contain a small, hairy, four- to six-lobed flower envelope and three to four styles. The male catkins also arise on the leaf axils of young branches. They are bright red at the beginning and stand upright, older catkins are yellow and pendulous, 4 to 7 cm (1+1⁄2 to 2+3⁄4 in) long and have a whitish hairy axis. The single flowers are sessile and have a densely hairy flower cover that is colored red when opened. The four to six stamens are whitish with yellow, egg-shaped anthers. They are longer than the bracts.


The fruit clusters are 0.5 to 4 cm (1⁄4 to 1+1⁄2 in) long and carry two to eight acorns. About half of the fruits are enclosed in the fruit cup (cupule); the fruit cups are 2 to 2.5 cm (3⁄4 to 1 in) in diameter. The upper scales of the cupula are gray and hairy, in the subspecies Quercus suber occidentalis the scales are close together or are fused. The size of the acorns varies between lengths of 2 to 4.5 cm (3⁄4 to 1+3⁄4 in) and diameters of 1 to 1.8 cm (1⁄2 to 3⁄4 in). The fruit casing (pericarp) is bare, smooth and shiny brownish red. The hilum (the starting point of the seed) is convex and has a diameter of 6 to 8 mm (1⁄4 to 3⁄8 in).


Quercus suber is a species of the Cerris section to which, for example, the following species also belong:
Valonia oak (Quercus macrolepis)
Turkey oak (Quercus cerris)
Quercus × crenata
Macedonian oak (Quercus trojana)
Characteristic for the section are the hairless pericarp and the usually two-year ripening time of the fruits. The cork oak is an exception because the fruits can ripen in both the first and the second year.
In the species Quercus suber two subspecies are distinguished:
Quercus suber subsp. suber: Nominal taxon
Quercus suber subsp. occidentalis(Gay) Bonnier & Layens: It differs from the nominate form in the shape of the cupula scales, the longer development time of the fruits and the semi-evergreen foliage. The distribution area of the subspecies is the Portuguese Atlantic coast.
Together with the Turkey oak (Quercus cerris) and the holm oak (Quercus ilex), the cork oak forms hybrid bastards.
The scientific name Quercus suber is derived from the Latin word quercus, which the Romans used to describe the pedunculate oak (Quercus robur). The specific epithet suber means in Latin cork oak and also cork.


The cork oak occupies the area around the western Mediterranean basin. In Portugal, natural and cultivated stands cover an area of 750,000 hectares. There are natural populations of the nominate form at altitudes between 150 to 300 m (490 to 980 ft) above sea level, the subspecies occidentalis is found along the Atlantic coast. In Spain the occurrences remain mostly below 600 m (2,000 ft), but rarely reach heights of 1,200 m (3,900 ft). In Spain, cork oaks are common in the southern half of the country, as well as in the western and northeastern areas, but rare in central Spain. In Italy one finds natural occurrences along the Tyrrhenian Sea and in eastern Apulia on the Adriatic Sea. Also on the Adriatic is the cork oak on the Dalmatian coast. It is one of the most common forest trees in Sardinia. Natural and man-made occurrences exist in Africa on the Mediterranean coast of Tunisia, Algeria and Morocco and at altitudes up to 1,000 m (3,300 ft), on the High Atlas up to 2,000 m (6,600 ft). In its native range, cork oak forests cover approximately 22,000 square kilometres (8,500 square miles). Outside of its natural range, the cork oak is cultivated in the Crimea, the Caucasus, India and the Southwestern United States. The subspecies Quercus suber occidentalis also thrives in mild areas of England.
The species needs very little light and cannot survive in dense populations. It loves warmth, grows at annual mean temperatures of 13 to 17 °C (55 to 63 °F) and can withstand maximum temperatures of up to 40 °C (104 °F). In the area of distribution, the temperature rarely falls below freezing point, but temperatures down to −5 °C (23 °F) without damage and down to −10 °C (14 °F) without major damage can be tolerated. The cork oak is not hardy in Central Europe. It endures drought and survives dry periods in summer by reducing its metabolism. An annual rainfall of 500 to 700 millimetres (20 to 28 in) is considered optimal, in cooler locations 400 to 450 millimetres (16 to 18 in) can be sufficient with enough humidity. Cork oaks have low soil demands and also grow in poor, dry or rocky locations. They rarely thrive on calcareous soils, but they are often found on crystalline slates, on gneiss, granite and sands. The acidity of the soil should be between pH 4.5 and 7.
The cork oak is considered a pyrophyte because it recovers quickly after forest fires as it is protected by the cork.


The cork oak forest is one of the major plant communities of the Mediterranean woodlands and forests ecoregion. In natural populations, the cork oak grows together with the holm oaks (Quercus ilex, Quercus rotundifolia), the downy oak (Quercus pubescens), the maritime pine (Pinus pinaster), the stone pine (Pinus pinea), the strawberry tree (Arbutus unedo) and the olive tree (Olea europaea), in cooler locations also with the sweet chestnut (Castanea sativa). In addition to these tree species, the shrub-forming species include the Kermes oak (Quercus coccifera), the holly buckthorn (Rhamnus alaternus), species of the genus Phillyrea, the myrtle (Myrtus communis), the green heather (Erica scoparia), the common smilax (Smilax aspera) and the Montpellier cistus (Cistus monspeliensis) are often found together with the cork oak.
Cork oak forests are home to several rare species, such as the Iberian Peninsula for the threatened Iberian lynx (Lynx pardinus) and the endangered Iberian imperial eagle (Aquila adalberti), and a large part of the European crane population winters here. In the northwestern Maghreb, some cork oak forests are habitat to the endangered Barbary macaque (Macaca sylvanus), a species whose habitat is fragmented and whose range was prehistorically much wider. The Berber deer (Cervus elaphus subsp. Barbarus) lives in the cork oak forests of Tunisia.
As a pyrophyte, this tree has a thick, insulating bark that makes it well adapted to forest fires. After a fire, many tree species regenerate from seeds (as, for example, the maritime pine) or resprout from the base of the tree (as, for example, the holm oak). The bark of the cork oak allows it to survive fires and then simply regrow branches to fill out the canopy. The quick regeneration of this oak makes it successful in the fire-adapted ecosystems of the Mediterranean biome.


The cork oak enters into a mycorrhizal symbiosis with several types of fungus. The fine root system of the oak is in close contact with the mycelium of the fungus. The oak receives water and nutrient salts from the fungus in exchange for products of photosynthesis. Such a symbiosis exists among others with the following species:
Caesar's mushroom (Amanita caesarea)
Death cap (Amanita phalloides)
Panther cap (Amanita pantherina)
Gilbert's limbed lepidella (Amanita gilbertii)
Cep (Boletus edulis)
Russula rubra


Cork oak is relatively resistant to pathogens, but some diseases occur in the species. Leaf spot can be caused by the fungus Apiognomonia errabunda. Other fungi can cause leaf scorching, powdery mildew, rust, and cankers.
The most virulent cork oak pathogen may be Diplodia corticola, a sac fungus which causes sap-bleeding sunken canker wounds in the wood, withering of the leaves, and lesions on the acorns. The fungus Biscogniauxia mediterranea is becoming more common in cork oak forests. Its fruiting bodies appear as charcoal-black cankers. Both of these fungi are transmitted by the oak pinhole borer (Platypus cylindrus), a species of weevil.
The common water mould Phytophthora cinnamomi grows in the roots of the tree and has been known to devastate cork oak woodlands.
Several species of butterflies damage the cork oak, the most important being the gypsy moth (Lymantria dispar). The species lays its eggs in the bark of the branches and trunks, and the caterpillars that hatch in spring are distributed in the crown and eat them bare. The bacterial species Bacillus thuringiensis is used as a biological plant protection agent against the gypsy moth. Another pest is the green oak tortrix (Tortrix viridana), whose caterpillars eat flowers and young leaves and roll them up with thread to form typical coils. The lackey moth (Malacosoma neustria) also causes damage to the leaves, sticking its eggs to the bark of thin twigs in multiple rows, and also the brown-tail moth (Euproctis chrysorrhoea), whose caterpillars skeletonize the leaves and further damage the tree after overwintering in spring. A special cork pest is the jewel beetle Coraebus undatus, which lays its eggs in the cork tissue. Another harmful species of beetle is the great capricorn beetle (Cerambyx cerdo), whose larvae eat long corridors in the oak wood.
Unfavorable climatic conditions and fungal attack are made responsible for the weakening of trees and for crown damage. Such fungal parasites of weakness are Botryosphaeria stevensii, Biscogniauxia mediterranea, Endothiella gyrosa and representatives of the mold genus Fusarium. Drought and parasite infestation are also considered to be the cause of the weakness syndrome in parts of Spain and Portugal.


The cork oak is grown for the production of cork in several Mediterranean countries. The centers of cork production are in southern Portugal (accounting for 50% of the total production) and southern Spain, where low trees with large crowns and strong branches are grown in large areas, which provide the highest yield of cork. These mostly extensively managed habitats are called montados in Portugal and dehesas in Spain. They are considered to be extremely valuable from the point of view of biodiversity and cultural heritage.
The cork consists of dead, air-filled, thin-walled cells and contains cellulose and suberin. Cork is heat and sound insulating, the suberine gives it water-repellent properties. The cork layer is replicated by the cork-producing phellogen and can therefore be harvested repeatedly without damaging the tree too much. The first harvest usually takes place after about 25 years with a trunk diameter (DBH) of 70 cm (28 in), though new techniques (such as better irrigation systems) could shorten it to only 8 to 10 years. The first cork layer is called “male cork” or “virgin cork”, is still not very elastic and cracked and is only used for insulating mats. The second harvested cork (known as secundeira), has a more regular structure and is softer, but is still only used for insulation and in decorative objects. Only the following cork harvests deliver a higher quality cork, the "female cork", which can be used commercially in full. The best quality cork is obtained from the third and fourth harvest. Cork harvesting takes place every nine to twelve years when a layer thickness of 2.7 to 4 cm (1 to 1+1⁄2 in) is reached. Under favorable (warm) conditions, the harvest can take place every eight years, in North Africa every seven years. A cork oak can be harvested five to seventeen times in total. In order to minimize the damage to the trunk surface, harvesting can be carried out every three years, whereby only a third of the usable surface is removed. An important maintenance measure is pruning, which begins around the age of ten at a height of about 3 m (10 ft). Some sources say an oak can provide around 100 to 200 kilograms (220 to 440 pounds) of cork over its lifespan, and one hectare around 200 to 500 kg (440 to 1,100 lb) per year while others suggest a single tree can produce on average 40 to 60 kg (88 to 132 lb) of cork per harvest, a comparatively higher value, as cork oaks can live more than 200 years in good conditions.
The cork is mainly used for the production of stoppers and corks, as well as for heat and sound insulation, cork
paper, badminton shuttlecocks, cricket balls, handles of fishing rods and hand tools, special devices for the space industry and for other technical applications (including composite materials, shoe soles, floor coverings). Bottle cork production accounts for around 70% of the added value in cork cultivation. Since natural corks are increasingly being replaced by plastic or sheet metal closures, there could be a significant decline in the cork oak population in southwestern Europe, which endangers the biodiversity in these areas.
The bark, which contains around twelve percent extractable tannin, is also used. In addition, the acorns are used as feed in extensive pig fattening (acorn fattening). One tree can provide 15 to 30 kg (33 to 66 lb) of acorns per year.
Cork oaks cannot legally be cut down in Portugal, except for forest management felling of old, unproductive trees, and, even in those cases, farmers need special permission from the Ministry of Agriculture.
Cork harvesting is done entirely without machinery, being dependent solely on human labour. Usually five people are required to harvest the tree's bark, using a small axe. The process mandates specialized training due to the skill required to harvest bark without inflicting too much damage to the tree.
The European cork industry produces 300,000 tonnes of cork a year, with a value of €1.5 billion and employing 30,000 people. Wine corks represent 15% of cork usage by weight but 66% of revenues.
Cork oaks are sometimes planted as individual trees, providing a minor income to their owners. The tree is also sometimes cultivated for ornament. Hybrids with Turkey oak (Quercus cerris) are not uncommon, both where their ranges overlap in the wild in southwest Europe and in cultivation; the hybrid Quercus × hispanica is known as Lucombe oak, for William Lucombe, who first identified it.
Some cork is also produced in eastern Asia from the related Chinese cork oak (Quercus variabilis).


The cork oak is featured in the city arms of several cities in Portugal, such as the city of Reguengos de Monsaraz, which shows a freshly harvested cork tree.
In 2007, a 2 euro commemorative coin with the motif of a cork oak was issued in Portugal in memory of the Portuguese Presidency of the European Union.


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.