Difference between revisions of "Oak"

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{{SPlantbox
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|familia=Fagaceae
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|genus=Quercus
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|common_name=Oak
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|habit=tree
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|Min ht metric=cm
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|Temp Metric=°F
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|image=Quercus robur.jpg
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|image_width=180
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|image_caption=Foliage and acorns of Pedunculate oak (Quercus robur)
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}}
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{{Inc|
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Oak. Plants of the genus Quercus (which see). The word is also applied to other plants to some extent, from resemblances in form of tree, in leaf, or in hardness of wood. In Australia, where there are no species of Quercus, the word oak is applied to the species of Casuarina, "from a fancied resemblance," as Maiden says, "of the wood of casuarinas to that of oak." Other plants in Australia are sometimes known as oaks. The silk oak of florists is Grevillea robusta. The Jerusalem oak is Chenopodium Botrys, probably from the shape of the leaves. Poison oak is Rhus Toxicodendron, and related species.
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}}
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:''This article is about oaks (Quercus). For other uses of "Oak" or "Oak tree", see [[Oak (disambiguation)]]''
 
:''This article is about oaks (Quercus). For other uses of "Oak" or "Oak tree", see [[Oak (disambiguation)]]''
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{{Taxobox
 
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| color = lightgreen
 
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| name = Oaks
 
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| image = Quercus robur.jpg
 
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| image_width = 240px
 
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| image_caption = Foliage and acorns of ''[[Pedunculate oak|Quercus robur]]''
 
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| regnum = [[Plant]]ae
 
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| phylum = [[flowering plant|Magnoliophyta]]
 
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| classis = [[dicotyledon|Magnoliopsida]]
 
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| ordo = [[Fagales]]
 
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| familia = [[Fagaceae]]
 
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| genus = '''''Quercus'''''
 
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| genus_authority = [[Carolus Linnaeus|L.]]
 
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| subdivision_ranks = [[Species]]
 
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| subdivision =
 
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See [[List of Quercus species|List of ''Quercus'' species]]
 
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}}
 
  
 
The term '''oak''' can be used as part of the common name of any of several hundred species of [[tree]]s and [[shrub]]s in the [[genus]] ''Quercus'', and some related genera, notably ''[[Cyclobalanopsis]]'' and ''[[Lithocarpus]]''. The genus is native to the northern hemisphere, and includes [[deciduous]] and [[evergreen]] species extending from cold latitudes to tropical [[Asia]] and the [[Americas]].  
 
The term '''oak''' can be used as part of the common name of any of several hundred species of [[tree]]s and [[shrub]]s in the [[genus]] ''Quercus'', and some related genera, notably ''[[Cyclobalanopsis]]'' and ''[[Lithocarpus]]''. The genus is native to the northern hemisphere, and includes [[deciduous]] and [[evergreen]] species extending from cold latitudes to tropical [[Asia]] and the [[Americas]].  
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Oaks have spirally arranged [[leaf|leaves]], with a lobed margin in many species; some have serrated leaves or entire leaves with a smooth margin. The [[flower]]s are [[catkin]]s, produced in spring. The [[fruit]] is a [[nut (fruit)|nut]] called an [[acorn]], borne in a cup-like structure known as a [[cupule]]; each acorn contains one seed (rarely two or three) and takes 6-18 months to mature, depending on species. The [[live oak|"live oaks"]] (oaks with [[evergreen]] leaves) are not a distinct group, instead with their members scattered among the sections below.
 
Oaks have spirally arranged [[leaf|leaves]], with a lobed margin in many species; some have serrated leaves or entire leaves with a smooth margin. The [[flower]]s are [[catkin]]s, produced in spring. The [[fruit]] is a [[nut (fruit)|nut]] called an [[acorn]], borne in a cup-like structure known as a [[cupule]]; each acorn contains one seed (rarely two or three) and takes 6-18 months to mature, depending on species. The [[live oak|"live oaks"]] (oaks with [[evergreen]] leaves) are not a distinct group, instead with their members scattered among the sections below.
  
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==Classification==
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{{Inc|
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The genus is divided into a number of sections:
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Quercus (ancient Latin name). Fagaceae. Oak. Ornamental trees, rarely shrubs, grown chiefly for their handsome foliage and interesting habit; many species are important timber trees. See Oak.
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*Sect. ''Quercus'' (synonyms ''Lepidobalanus'' and ''Leucobalanus''), the [[List of Quercus species#Section Quercus|oaks]] of [[Europe]], Asia and [[North America]]. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless. Leaves mostly lack a bristle on lobe tips, which are usually rounded.
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*Sect. ''Mesobalanus'', the [[List of Quercus species#Section Mesobalanus|Hungarian oak and its relatives]] of Europe and Asia. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. ''Quercus'' and sometimes included in it).
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Deciduous or evergreen trees, rarely shrubby: winter buds with usually many imbricate scales: lvs. alternate, short-petioled, with deciduous stipules, pen- ninerved, serrate, lobed or pinnatifid, rarely entire: fls. monoecious; the staminate in slender, pendulous catkins with 4-7-parted calyx and 4-12, usually 6, stamens; pistillate in 1- to many-fld. spikes in the axils of the young lvs., each fl. consisting of an incompletely 3-, or rarely 4-5-celled ovary, surrounded by imbricate bracts; style short or elongated, dilated above and stigmatic on the inner face: fr. a 1-seeded subglobose to oblong nut, surrounded at the base or sometimes almost inclosed by a cup-like involucre.—More than 200 species are known, distributed through the colder and temperate regions of the northern hemisphere and in the mountains of the tropics. The numerous species are usually divided into 3 subgenera. The species of the subgenus Cyclobalanopsis which has the scales of the cup connate into concentric rings are all Asiatic. The American species belong to Lepidobalanus (balanos is Greek for acorn) and to Erythrobalanus. In the former, comprising the white oak tribe, the acorns mature the first year (Fig. 3304). In the latter, comprising the black oaks, the acorns mature the second year (Fig. 3305). Besides the 200 species, about 40 hybrids have been recorded. Pasania, often included under Quercus, is now usually considered a distinct genus, which see. The latest monograph of the whole genus is by A. DeCandolle in "Prodromus," vol. 16, 2, pp. 1-108 (1864-1868). Important illustrated works on American oaks are A. Michaux, "Histoire des Chenes de l'Amerique" (1801), with 36 plates; Kellogg and Greene. "Illustrations of West American Oaks" (1889), with 37 plates; Sargent, "Silva of North America," vol. 8 (1895), with 82 plates, and Liebmann, "Chenes de l'Amerique Tropicale" (1869), with 47 plates. Most of the European and west Asian oaks are figured in Kotschy "Eichen Europas und des Orients" (1862), with 40 colored plates. For comparative illustrations of lvs. see M.D. 1900, p. 32; R.B. 27, p. 61; G.W. 7, pp. 570, 571, 573; for those of frs. see M.D. 1900, p. 40; R.B. 27, p. 109.
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*Sect. ''Cerris'', the [[List of Quercus species#Section Cerris|Turkey oak and its relatives]] of Europe and Asia. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
 
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*Sect. ''Protobalanus'', the [[List of Quercus species#Section Protobalanus|Canyon live oak and its relatives]], in southwest [[United States]] and northwest [[Mexico]]. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
 
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*Sect. ''Lobatae'' (synonym ''Erythrobalanus''), the [[List of Quercus species#Section Lobatae|red oaks]] of North America, [[Central America]] and northern [[South America]]. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with spiny bristles at the lobe tip.
 
  
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[[List of Quercus species|'''Full list of ''Quercus'' species''']]
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The oaks are mostly trees, often tall with massive trunk and stout spreading limbs, with medium-sized, short-petioled leaves, usually more or less lobed, dentate or serrate, rarely entire, with inconspicuous flowers, the staminate ones in slender pendulous catkins and with fruits or "acorns" consisting of a globular to oblong nut inclosed at the base only, rarely wholly or nearly wholly, by a cup-like involucre. The oaks comprise some of the most important forest trees of the northern hemisphere. The wood of most species is strong, tough, hard and durable, and highly valued for many purposes, especially ship-building, construction, for furniture, and in the manufacture of wagons, tools and many other articles. The bark of some species, in America that of Q. velutina and Q. Prinus, is used for tanning leather. Cork is obtained from the bark of Q. Suber and Q. occidentalis in southern Europe. The bark of a few species has also been employed in medicine. The acorns of several species are edible, in America especially those of Q. Prinus, Q. Emoryi and Q. lobata; in Europe those of Q. Ilex var. Ballota and Q. Egilops; in Japan those of Q. glauca; in many European countries the acorns of all species are an important food for hogs. In eastern Asia a silkworm feeds on the leaves of different species. A parasitic insect living on Q. coccifera in southern Europe and northern Africa yields a scarlet dye. Galls caused by the puncture of certain insects are used for tanning and dyeing and are now chiefly obtained from Q. Ilex var. infectoria in western Asia. Some of the above-mentioned species are described only in the supplementary list, page 2890.
  
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[[Image:Quercus stellata.jpg|thumb|A hybrid white oak, possibly ''[[Post oak|Quercus stellata]]'' × ''[[Chinkapin oak|Q. muhlenbergii]]'']]
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The deciduous species are mostly hardy North, while of the evergreen ones none seems to be hardy farther north than Washington, D.C.; some half-evergreen oaks, as Q. Pseudoturneri and Q. macedonica, will probably prove hardy in the vicinity of New York.  
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[[Hybrid]]s are common in oaks but usually only between species within the same section; no verified inter-section hybrids are known, except between species of sections ''Quercus'' and ''Mesobalanus'', where several occur.
 
  
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The genus ''[[Cyclobalanopsis]]'', here treated as a distinct genus following the [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=2&taxon_id=108828 ''Flora of China''], is often included within ''Quercus'' as a distinct subgenus.
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Most of the oaks are stately trees of noble and majestic habit with stout, wide-spreading branches; some, as Q. alba, Q. Garryana, Q. vir- giniana, and Q. chrysolepis, often cover a space more than 100 feet in diameter; others, as Q. macrocarpa, Q. montana and Q. velutina, have a more oval, round- topped head, while Q. palustris and Q. imbricaria form symmetrical broad pyramids. A very few hardy species are shrubs, generally called scrub oaks, as Q. prinoides and Q. ilicifolia. Oaks rank among our most valuable park and avenue trees, and are as beautiful when grown as single trees as they are when grouped together and forming groves and woods. As avenue trees, Q. palustris, Q. rubra, Q. coccinea. Q. imbricaria and Q. Phellos are among the best, the last- named when medium-sized trees are desired; in the southern states, Q. laurifolia, Q. nigra, and the evergreen Q. virginiana are preferred. The shrubby species, like Q. prinoides and Q. ilicifolia, may be used for covering rocky hillsides and dry ridges.
  
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==Uses==
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Oak leaves are always beautiful. They have many shades of green; especially attractive are some with leaves of contrasting colors, the under side being silvery white, the upper one dark green, as in Q. Muhlenbergii, Q. macrocarpa, Q. Prinus, and some foreign evergreen species. In many oaks the leaves show a handsome pink or crimson color when unfolding, and some species assume brilliant autumnal tints. Especially beautiful in autumn are Q. coccinea and Q. palustris, with the foliage turning brilliant scarlet; Q. rubra, Q. imbricaria, and Q. Prinus, which turn bright or dark red; Q. alba, violet or vinous purple; Q. lyrata, scarlet or orange; Q. Phellos, pale yellow; Q. montana, orange or orange- brown; Q. falcata and Q. ilicifolia, orange-brown or yellow; Q. stellata and Q. nigra, brown or dull orange. Some of the foreign species, like Q. sessiliflora and also Q. Robur, Q. Cerris, Q. lanuginosa, Q. glandulifera, and others, retain the green color until late in fall. Besides our native evergreen species, the Japanese Q. acuta, Q. myrsinaefolia, and Q. glauca are among the best evergreen oaks for cultivation in the South; the European Q. Ilex and Q. Suber are also handsome evergreen trees.  
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Oaks are [[hardwood]] trees, and the [[wood]] is commonly used in [[furniture]] and flooring. Oak wood has a density of about 0.75 g/cm³.
 
  
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The bark of ''Quercus suber'', or [[Cork oak]], is use
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Generally the oaks grow best in a moderately moist rich soil, including heavy clay; some, as Q. bicolor, Q. nigra, Q. alba, Q. Phellos, Q. falcata, and Q. virginiana, prefer moister situations and grow naturally in low and often even in swampy ground; while others, especially the red oaks, like Q. rubra, Q. coccinea, Q. imbricaria, Q. marilandica, Q. montana. and Q. stellata, grow well in drier, rocky or sandy soil, and the scrub oaks on dry and barren soil. The black and red oaks especially the pin oak, are usually easily transplanted and large trees are moved successfully, while the white oaks are more particular and only younger nursery- grown trees can be safely transplanted.
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d to produce [[wine]] [[stopper (plug)|stopper]]s (corks). This species grows in the [[Mediterranean Sea]] region, with [[Portugal]], [[Spain]], [[Algeria]] and [[Morocco]] producing most of the world's supply. Some European and American oak species are used to make [[Barrel (storage)|barrel]]s where wine and other spirits are [[Aging barrel|aged]]; the barrels, which are in some cases charred before use, contribute to the taste, aroma, and color of the contents.
 
  
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Of the North American oaks, the [[Northern red oak]] ''Quercus rubra'' is the most prized of the red oak group for lumber, all of which is marketed as red oak regardless of the species of origin. The standard for the lumber of the white oak group, all of which is marketed as white oak, is the [[White Oak]] ''Quercus alba''. White Oak is often used to make wine barrels. The wood of [[Pedunculate Oak]] ''Quercus robur'' and [[Sessile Oak]] ''Quercus petraea'' are extensively used in [[Europe]].
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Oaks are propagated usually by seeds sown immediately after gathering in fall; this is especially necessary with Q. alba. Q. virginiana, and some other white oaks which sprout as soon as they are ripe; but only the root is produced in fall, while the stem does not appear until the following spring. The seeds of red and black oaks, and also of Q. Robur, if not sown at once should be stratified and sown early in spring. Acorns should be packed in earth, moss, or sawdust when shipped for a great distance. Varieties are usually grafted on potted stock in the greenhouse in early spring or sometimes in August. As a stock Q. Robur is preferred, but Q. rubra, Q. velutina, and Q. montana are also employed. It is probably safer to graft varieties of white and of red oak each on stock of the same group. The evergreen species are sometimes increased by layers and also by cuttings.}}
  
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The [[bark]] of the White Oak is dried and used in medical preparations. Oak bark is also rich in [[tannin]], and is used by tanners for [[tanning]] [[leather]]. Acorns are used for making flour or roasted for acorn coffee.  Oak galls were used for centuries as the main ingredient in manuscript ink, harvested at a specific time of year.
 
  
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Japanese oak is used in the making of professional drums from manufacturer [[Yamaha Drums]]. The rough, hard surface of oak gives the drum a brighter and louder tone compared to traditional drum materials such as [[maple]] and [[birch]].
 
  
 
==Cultivation==
 
==Cultivation==
 
Oak catkins are made up of small, yellowish-green flowers. Acorns appear after the female flowers are fertilized in spring.  They are typically brown, tan, yellow, light green, deep green or grayish green. Oaks grow slowly and usually do not bear acorns until they are about 20 years old. Acorns require [[Stratification (botany)|stratification]] to stimulate sprouting. Most [[white oaks]] need immediate stratification; species such as the [[Chestnut oak]] (''Quercus montana'') will sprout a root upon falling and must have a suitable substrate for immediate rooting. Many red oak acorns can be stratified for up to two years before sprouting. The life span of oaks typically ranges from 200 to 600 years, with a few species reaching 1,000 years.
 
Oak catkins are made up of small, yellowish-green flowers. Acorns appear after the female flowers are fertilized in spring.  They are typically brown, tan, yellow, light green, deep green or grayish green. Oaks grow slowly and usually do not bear acorns until they are about 20 years old. Acorns require [[Stratification (botany)|stratification]] to stimulate sprouting. Most [[white oaks]] need immediate stratification; species such as the [[Chestnut oak]] (''Quercus montana'') will sprout a root upon falling and must have a suitable substrate for immediate rooting. Many red oak acorns can be stratified for up to two years before sprouting. The life span of oaks typically ranges from 200 to 600 years, with a few species reaching 1,000 years.
  
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==Diseases and pests==
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===Propagation===
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<!--- Type propagation info below this line, then delete this entire line -->
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===Pests and diseases===
 
[[Sudden Oak Death]] (''Phytophthora ramorum'') is a [[water mould]] that can kill oaks within just a few weeks. [[Oak Wilt]], caused by the fungus ''Ceratocystis fagacearum'' (a fungus closely related to [[Dutch Elm Disease]]), is also a lethal disease of some oaks, particularly the red oaks (the white oaks can be infected but generally live longer). Other dangers include wood-boring [[beetle]]s, as well as root [[rot]] in older trees which may not be apparent on the outside, often only being discovered when the trees come down in a strong [[gale]]. Oaks are used as food plants by the [[larva]]e of [[Lepidoptera]] species.
 
[[Sudden Oak Death]] (''Phytophthora ramorum'') is a [[water mould]] that can kill oaks within just a few weeks. [[Oak Wilt]], caused by the fungus ''Ceratocystis fagacearum'' (a fungus closely related to [[Dutch Elm Disease]]), is also a lethal disease of some oaks, particularly the red oaks (the white oaks can be infected but generally live longer). Other dangers include wood-boring [[beetle]]s, as well as root [[rot]] in older trees which may not be apparent on the outside, often only being discovered when the trees come down in a strong [[gale]]. Oaks are used as food plants by the [[larva]]e of [[Lepidoptera]] species.
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*''See also [[list of Lepidoptera which feed on Oaks]]''
 
  
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==Cultural significance==
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==Species==
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[[Image:5ec ger.png|right|thumb|An oak twig is depicted on the back of [[German euro coins|German 1-, 2- and 5-cent coins]]]]  
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The genus is divided into a number of sections:
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The oak is a common [[symbol]] of [[Virtue|strength]] and [[endurance]] and has been chosen as the [[national tree]] of [[England]], [[France]], [[Germany]] and the [[United States]].
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*Sect. ''Quercus'' (synonyms ''Lepidobalanus'' and ''Leucobalanus''), the [[List of Quercus species#Section Quercus|oaks]] of [[Europe]], Asia and [[North America]]. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless. Leaves mostly lack a bristle on lobe tips, which are usually rounded.
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*Sect. ''Mesobalanus'', the [[List of Quercus species#Section Mesobalanus|Hungarian oak and its relatives]] of Europe and Asia. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. ''Quercus'' and sometimes included in it).
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*Sect. ''Cerris'', the [[List of Quercus species#Section Cerris|Turkey oak and its relatives]] of Europe and Asia. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
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*Sect. ''Protobalanus'', the [[List of Quercus species#Section Protobalanus|Canyon live oak and its relatives]], in southwest [[United States]] and northwest [[Mexico]]. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
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*Sect. ''Lobatae'' (synonym ''Erythrobalanus''), the [[List of Quercus species#Section Lobatae|red oaks]] of North America, [[Central America]] and northern [[South America]]. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with spiny bristles at the lobe tip. 
  
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[[Thor's Oak]] was a sacred tree of the Germanic [[Chatti]] tribe. Its destruction marked the [[Christianisation]] of the heathen tribes by the [[Franks]]{{Fact|date=April 2007}}.
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[[List of Quercus species|'''Full list of ''Quercus'' species''']]
  
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In the [[Bible]], the oak tree at [[Shechem]] is the site where Jacob buries the foreign gods of his people (Gen. 35.4) . In addition, Joshua erects a stone under an oak tree as the first covenant of the Lord (Josh. 24.25-7). See other [http://www.biblegateway.com/quicksearch/?quicksearch=oak&x=0&y=0 examples] from the Bible.
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[[Image:Quercus stellata.jpg|thumb|A hybrid white oak, possibly ''[[Post oak|Quercus stellata]]'' × ''[[Chinkapin oak|Q. muhlenbergii]]'']]
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[[Hybrid]]s are common in oaks but usually only between species within the same section; no verified inter-section hybrids are known, except between species of sections ''Quercus'' and ''Mesobalanus'', where several occur.
  
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In [[Classical mythology]] the oak was a symbol of [[Zeus]] and his sacred tree.
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The genus ''[[Cyclobalanopsis]]'', here treated as a distinct genus following the [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=2&taxon_id=108828 ''Flora of China''], is often included within ''Quercus'' as a distinct subgenus.
  
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Several individual oak trees, such as the [[Royal Oak (tree)|Royal Oak]] in Britain and the [[Charter Oak]] in the United States, are of
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{{Inc|
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great historical or cultural importance; for a list of important oaks, see [[:Category:Individual oak trees|Individual oak trees]].
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Index.
  
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[[Iowa]] has designated the oak as its official [[list of U.S. state trees|state tree]] in 1961, and the White Oak is the state tree of [[Connecticut]], [[Illinois]] and [[Maryland]].
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acuminata,            21.Doumetii,          32.obtusiloba,          28.
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acuta,                45.ellipsoidalis,      5.occidentalis,        38.
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acuteserrata,        20.falcata,        8, 9.olivaeformis,        26.
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Egilops,    34 and suppl.fastigiata,        32.pagodaefolia,        9.
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agrofolia,            42.femina,            32.palustri-imbricaria, 15.
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alba,                31.ferruginea,        12.palustris,        2, 23.
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albo-variegata,      32.filicifolia,      32.pannonica,          36.
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aliena,              20.Fordii,            39.pectinata,          32.
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ambigus,              1.Garryana,          29.pedunculata,        32.
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Ambrozyana,          37.glandulifera,      19.pendula,    32, 34, 35.
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aquatica,            11.glauca,            43.Phellos,            13.
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argenteo-marginata,  32.grosseserrata,    18.pinnatifida, 17, 31, 34.
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argenteo-marginata,  32.Hartwissiana,      34.platanoides,        25.
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argenteo-picta,      32.heterophylla,      32.prinoides,          22.
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asplenifolia,        32.Hindsii,          30.Prinus,          21-25.
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atropurpurea,        32.humilis,      22 and Pseudaegilops,      34.
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aures,                33.                suppl.Pseudoturneri    19 and
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aureo-varoegata,      32.hungarica,        36.                  suppl.
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austriaca,            37.hybrida,          32.pubescens,          34.
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Ballota,              39.Ilex,              39.purpurascens,        32.
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bambusaefolia,        44.ilicifolia,        10.purpurea,        32, 33.
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Banisteri,            10.imbricaria,        15.pyrenaica,          35.
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bicolor,              25.ioreauensis,      32.repanda,            31.
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borealis,          1, 8.Kelloggii,          6.rosacea,            32.
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Buergeri,            45.laciniata, 32, 33, 37.Robur,           32, 33.
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Bungeana,            16.lanuginosa,        34.rubra,            1, 8.
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californica,          16.            and suppl.sanguinea,          32.
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camata,              35.laurifolia,        14.Sargemtii,          24.
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Castanea,             21.lobata,            30.Saulii,              31.
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Cerris,              37.Louettei,          33.Schneckii,            4.
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Chincapin,            22.lyrata,            27.serrata,  16 and suppl.
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chinensis,            16.macrocarpa,        26.sessiliflora,        33.
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chrysolepis,          41.marilandica,      12.sessilis,            33.
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coccinea,          1, 3.marmorta,          32.stellata,            28.
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comptoniaefolia,      32.maxima,            8.Suber,              38.
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Concordia,            32.mespilifolia,      33.sublobata,          33.
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conferta,            36.Michauxii,        23.texana,              4.
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contorta,            32.minor,            28.tinctoria,            7.
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crinita,              35.missouriensis,      7.tomentosa,          25.
 +
crispata,            34.mongolica,        18.Toza,                35.
 +
crispula,            18.montana,          24.tricolor,            32.
 +
cuneata,              8.monticola,        24.uliginosa,          11.
 +
Daimio,              17.Muhlenbergii,      21.variabilis,          16.
 +
Dauvessei,            32.myrsinaefolia,    44.velutina,            7.
 +
dentata,          17, 19.nana,              10.Vibrayana,          44.
 +
digitata,              8.nigra,    11, 12, 32.virens,              40.
 +
discolor,            25.obovata,          17.virginiana,          40.
  
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"Ambrosian Oaks" set to the [[Finlandia Hymn]] is the school song of [[St. Ambrose University]] in [[Davenport, Iowa]].
+
The species in the following list are not hardy North except when mentioned:
 +
Q. acutissima, Carruthers=Q. serrata.—Q. Aegilops, Linn. Evergreen tree, to 60 ft.: allied to Q. Cerris: lvs. lobed-dentate with acute sinuses, fulvous-tomentose at first: cup large, with spreading, flat, lanceolate scales, not much to one-half shorter than acorn. S. Italy, Greece.—Q. Aizoon, Koehne=Q. Pseudoturneri.—Q. alnifolia, Poech. Evergreen shrub: lvs. orbicular or oval, dentate, shining above, yellow-tomentose beneath, 1-2 in. long: cup with recurved lanceolate bracts; acorn 1 1/2 in. long. Crete. Gn. 18, p. 486;40, p. 95. A.G. 13:436.—Q. aquifolioides, Rehd. & Wilson. Evergreen shrub or tree, to 30 ft.: branchlets pubescent: lvs. subsessile, elliptic or ovate-elliptic, auriculate, spiny-dentate or entire, lustrous above, yellowish brown-tomentose beneath, 1 1/4-3 in. long: fr. several, peduncled; cup saucer-shaped; acorn ovoid, 1/2in. long. W. China. Var. rufescens, Rehd. & Wilson (Q. Ilex var. rufescens, Franch.). Lvs. with yellowish gray, looser pubescence, older lvs. sometimes glabrous: scales of cup thicker, more villous. W. China.—Q. arkansana, Sarg. Allied to Q. marilandica. Tree, to 70 ft.: lvs. broadly obovate, cuneate, at maturity glabrous beneath except tufts in the axils, 2-3 1/2 in. long: cup shallow; nut broadly ovate, 1/3in. long. Ark. S.T.S. 2:152.-Q. austriaca sempervirens, Hort.= Q. Pseudoturneri.—Q. Boimtonii, Beadle. Allied to Q. stellata. Shrub. 3-15 ft.: lvs. obovate with 3-5 small obtuse lobes above the middle or nearly entire, 2-3 1/2 in. long: cup turbinate; acorn about 1/2in. long. Ala.—Q. brevifolia, Sarg.=Q. cinerea.—Q. castaneaefolia, C. A. Mey. Half-evergreen tree, to 70 ft.: lvs. oblong-lanceoate, serrate, tomentulose beneath, rarely almost glabrous, 4-6 in. long: cup with lanceolate recurved scales. W. Asia to N. Persia. G.W. 11, p. 199. Not or only half-hardy N.—Q. Catesbaei, Michx. Tree, to 60 ft.: lvs. similar to those of Q. cuneata, but rufous- tomentose when young, glabrous at length, except axillary tufts beneath, very short-petioled: cup turbinate with the scales extending above the rim and down the inner surface. N. C. to Fla. and La. S.S. 8:417.—Q. Chapmanii, Sarg. (Q. obtusiloba var. parvi- folia, Chapm.). Usually a shrub, rarely small tree; allied to Q. stellata: lvs. obovate-oblong and entire or slightly sinuately lobed toward the apex. S. C. to Fla. S.S. 8:370.—Q. chinensis, Abel. See Q. sclerophylla.—Q. cinera, Michx. Blue Jack. Small tree: allied to Q.imbricaria, but lvs. tomentulose beneath, smaller, elliptic to oblong-lanceolate, half-evergreen: cup saucer-shaped; acorn sub-globose. N. C. to Fla. and Texas. S.S. 8:431.—Q. cleistocarpa, Seemen=Pasania cleistocarpa, Schottky (P. Wilsonii, Schottky. Q. Wilsonii, Seemen). Evergreen tree, to 50 ft.: lvs. coriaceous, elliptic-oblong to oblong-lanceolate, acuminate, broadly cuneate at the base, lustrous above, covered beneath with a thin scaly grayish tomentum, becoming glabrescent, 2 1/2-6 in. long: fr. in short dense spikes, subglobose, about 4/3in. across, the cup nearly inclosing the acorn; scales adnate. Cent. and W. China.—Q. coccifera, Linn. Evergreen small tree or shrub: lvs. oval to oblong,
 +
spinose-dentate, almost glabrous, 1-2 in. long: cup with spreading or recurved rigid scales: maturation biennial. S. Eu. H.W. 2:25, p. 82.—Q. cuspidata, Thunb. See Castanopsis p. 2891.—Q. densiflora, Hook. & Arn.=Pasania densiflora.—Q. Douglasii, Hook. & Arn. Tree, to 60 ft., with dense, round-topped head: allied to Q. Garryana, but lvs. bluish green, less deeply lobed, often only sinuately dentate. Calif. S.S. 8:386.-Q. dumosa, Nutt. Evergreen rigid shrub to 8 ft. or occasionally tree to 30 ft.: lvs. oblong to obovate, entire or sinuately toothed, pubescent, grayish green, 1/4-2, rarely to 3 in. long: fr. usually solitary and sessile; acorn oval, 1/2-1 1/2 in. long, embraced one-third to two-thirds by the cup. Very variable. Calif. S.S. 8:392.—Q. Emoryi, Torr. Evergreen tree, to 40 ft.: allied to Q. chrysolepis: lvs. usually cordate, oblong-lanceolate, spiny-toothed, soon almost glabrous, 1-2 1/2 in. long: acorn oblong, 1/2-3/4in. high. Texas to Aris. S.S. 8:397.—Q. Engleriana, Seemen (Q. sutchuenensis, Franch.). Evergreen tree, about 30 ft.: branchlets brown, soon glabrous: lvs. ovate-oblong, acuminate, rounded at the base, with few small spiny appressed teeth, sometimes entire, finally glabrous, 2 1/2-5 in. long: fr. 1-3, short-stalked; acorn ovoid, scarcely 1/2in.; cup with thin glabrescent brown scales, cup-shaped. Cent. China.—Q. Esculus, Linn. A S. European form of Q. sessilifora, with the lvs. pubescent when young and deeply pinnatifid.: synonym of Q. sessilifora var. aurea, DC.—Q. Fabri, Hance. Tree, to 80 ft.: branchlets pubescent: lvs. short-stalked, obovate to oblong, obtusish, sinuately lobed with 6-10 pairs of short rounded rarely acutish lobes, grayish tomentulose and reticulate beneath, 3-6 in. long: fr. short-stalked; acorn oblong-cylindric, 3/4in. long. cup glabrescent, brown. China.—Q. Fargesii, Franch. =O. oxyodon var. Fargesii.-Q. fruticosa, Brot.=Q. humilis.—Q. fulhamnns, Hort. See Q. Lucombeana.—Q. Gambelii, Nutt. Small tree or shrub, very variable: allied to Q. alba: lvs. smaller, pale or yellowish green and usually finely pubescent below: fr. smaller, sessile. Colo. to Utah and Mex. S.S. 8:366, 367. Gt. 44, p. 7.—Q. georgiana, Curtis. Shrub, 6-8 ft., rarely small tree: allied to Q. palustris: lvs. smaller, less deeply lobed and lobes mostly entire. Ga, S.S. 8:425. Hardy.—Q. Gilliana, Rehd. & Wilson. Evergreen small tree, to 2O ft. or scrubby: lvs. subsessile, oval, rounded at the spiny-pointed apex, subcordate or rounded at the base, spiny-toothed, quite glabrous at maturity, 1-2 in. long: fr. sessile, ripening the first year; acorn ovoid, 1/2in. long, inclosed nearly one-half by the hemispherical cup. W. China.—Q. glabra, Thunb.= Pasania glabra.—Q. Grarmuntia, Linn.=Q. llex.—Q. Haas, Kotschy. Closely allied to Q. pedunculata: lvs. sparingly stellate-pubescent beneath, larger: fr. larger. E. Eu., W. Asia. Hardy.—Q. Henryi, Seemen=Pasania Henryi, Schottky. Evergreen tree, to 60 ft.: lvs. slender-petioled, oblong-lanceolate, acuminate, lustrous above, covered beneath with a thin scaly tomentum, finally glabrescent, 4-8 in. long: fr. in stout spikes 4-7 in. long; acorn depressed-globose, 2/3in. across, embraced only at the base by the saucer-shaped cup. Cent. China. —Q. heterophylla, Michx. Supposed hybrid of Q. Phellos and Q. velutina: lvs. oblong, narrowed into the petiole, sinuately lobed or toothed or entire. S.S. 8:436.—Q. humilis, Walt.=Q. cinerea.—Q. humilis, Lam. Half-evergreen shrub, with oval, coarsely dentate lvs., grayish tomentose beneath: fr. almost sessile. Portugal. Sometimes Q. prinoides is sold under this name.—Q. inacana, Roxbg. Evergreen tree, to 60 ft.: allied to Q. serrata: lvs. oblong to ovate-lanceolate, acuminate, mucronate-serrate, with 14-20 pairs of veins, glossy above, whitish tomentose beneath, 3-6 in. long: fr. sessile; acorn about 1 in. long, at first almost inclosed by the campanulate, rather thin cup. Himalayas. Sometimes united with Q. lanata.—Q. infectoria, Oliver=Q. lusitanica var. infectoria.—Q. insignis, Mart. A Gal., the Mexican white oak, has been intro. recently by the U. S. Dept. Agric.: said to be best suited to a moist warm climate: a rapid-growing tree, erect, 75 ft., and making large branches 3O-40 ft. from the ground: branchlets densely hairy: lvs. short-stalked, obovate-oblong, remotely serrate, hairy, on both sides, 5-9 in. long: fr. subsessile; cup 3/4in across, fulvous-pubescent.—Q. inversa, Lindl.= Pasania thalassica.—Q. Koehnei, Ambrozy (Q. Pseudoturneri, Veitch Cat., not Schneid.). Probably Q. Ilex X Q. sessiliflora. Lvs. oblong-obovate, cuneate, very obtuse at the apex, with few short lobes, glabrous; midrib yellow, changing to dull red in fall. Garden origin.—Q. lanata, Wall. Evergreen tree, to 80 ft.: allied to Q. incana: lvs. oblong-lanceolate, with 10-16 pairs of veins, remotely toothed, 4-8 in. long: fr. smaller, cup hemispherical. Himalayas. —Q. lanuginosa, Don=Q. lanata.-Q. Leana, Nutt. Supposed hybrid of Q. imbricaria and Q. velutina: lvs. oblong or obovate-oblong,sinuately toothed or entire, rounded at the base. S.S. 8:434. Hardy.—Q. Libani, Oliver. Half-evergeeen shrub or small tree: lvs. oblong-ovate, coarsely serrate, light green and at length almost glabrous beneath, 2—4 in. long: acorn almost wholly inclosed; scales little spreading. Asia Minor. R.H. 1872, p. 155; 1877, p. 173. (not p. 172. which is probably Q. AEgilops). Gn. 1, p. 618.—Q. Lucombeana, Sweet (Q. Cerris var. Lucombeana, Loud. Q. Cerris var. subperennis, DC.). Supposed hybrid of Q. Cerris and Q. Suber. Half-evergreen tree to 70 ft., with broad, round head: lvs. oval-ovate, coarsely serrate, tomentose beneath, 2-3 1/2 in. long: cup with subulate spreading scales. Probably of the same parentage as Q. fulhamensis, differing by symmetrical pyramidal habit and more corky bark. Gn. 27, pp. 476-8.—Q. lusitanica, Lam. Half-evergreen tree, sometimes shrub: lvs. oval to ovate-lanceolate, coarsely and deeply serrate, pubescent beneath, 1-2 in. long: cup with appressed scales, embracing one-half to one-third of the nut. S. Eu. Var. infectoria, DC., is more shrubby and has the lvs. less pubescent beneath.—Q. macedonica, DC. Evergreen tree or shrub: lvs. oval-oblong, serrate, light green and sparingly pubescent beneath, 1 1/2-3 in. long: cup with the lower scales appressed, the middle ones spreading and the upper ones inversed, almost inclosing the nut. Macedonia, Albania.—Q. macranthera, Fisch. & Mey. Tree, to 50 ft.: allied to Q. conferta: lvs. larger and less deeply lobed, with 8-10 ovate lobes on each side, each lobe 1/2-1 in. long, sometimes with 1-3 teeth on its lower side, pale and densely soft-pubescent beneath, 4-7 in. long: fr. nearly sessile; acorn about 1 in. long, embraced nearly half by the cup covered with lanceolate pubescent scales. Caucasus to N. Persia. A handsome and hardy oak with large striking foliage.—Q. macrolepis, Kotschy. A variety of Q. .AEgilops, with larger, less deeply lobed lvs. and the scales of the cup large and strongly recurved. Crete.— —Q. Maroaretta, Ashe. Allied to Q. stellata. Shrub or small tree, to 30 ft.: lvs. obovate, with 3-5 rounded lobes, pale green or glaucous and pubescent on the veins beneath, 2 1/2-3 1/2 in. long: nut ovoid-oblong, 1/2in. long, one-half or less included in the cup. Va. to Fla. and Ala.—Q. Mirbeckii, Durand. Allied to Q. lanuginosa. Tree, to 100 ft.: branchlets glabrous or nearly so: lvs. ovate-oblong, with 9-12 short obtusish teeth on each side, pubescent beneath while young, 4-6 in. long: fr. 1-4 on a stalk 1/2-1 in. long. N. Afr. G.M. 56:139.—Q. mongolica, Hort., not Fisch.=Q. lanuginosa.-Q. oblongifolia, Torr. Evergreen small tree, to 30 ft., with spreading, often contorted branches: allied to Q. undulata. Lvs. ovate to obovate, entire or spiny-toothed, glabrous, bluish green, 1-3 in. long: cup embracing about one-third of the ovate nut. Ariz. to Mex. and W. Texas. S.S. 8:388. G.F. 1:140.—Q. oxyodon, Miq. Half- evergreen tree, about 30 ft.: lvs. oblong, acuminate, rounded or broadly cuneate at the base, serrate, veins prominent, close and numerous, glaucescent and silky beneath, 2 1/2-7 in. long: fr. in short spikes; acorns ovoid, about 3/4in., cup with concentric crenate rings, grayish tomentulose. Cent. China, Assam. Var. Fargesii, Rehd. & Wilson. Lvs. smaller: rings of cup entire.— Q. phillyraeoides, Gray. Evergreen tree or shrub, with broadly oval to oblong-oval lvs., crenately serrate, except at the base, glabrous, 1-2 1/2 in. long: cup with appressed scales, small. Japan. S.I.F. 1:31.—Q. pontica, Koch. Tree or shrub: lvs. oblong-oval, serrate, glabrous, glaucescent beneath, 4-6 in. long: cup with ovate-lanceolate scales, inclosing about one-half of the nut. Asia Minor. Gt. 40, p. 510. Hardy.—Q. Pseudosuber, Santi. Evergreen or half-evergreen tree, allied to Q. Suber: bark less corky: lvs. more deeply serrate, thinner and less tomentose beneath: cup with recurved scales. Italy, N. Afr. H.W. 2, p. 82.—Q. Pseudoturneri, Schneid. (Q. Aizoon, Koehne. Q. Turneri, Hort., not Willd. Q. austriaca sempervirens, Hort.). Probably hyhrid of Q. Ilex and Q. pedunculata. Half-evergreen: lvs. oblong-obovate, acute, cuneate, with about 5 pairs of ascending acutish lobes, somewhat pubescent beneath, midrib yellow, 2-4 in. long: fr. long-stalked. Garden origin.—Q. Pseudoturneri, Veitch Cat.=Q. Koehnei.—Q. pumila, Walt. (Q. Phellos var. pumila, Michx. Q. sericea, Willd.). Half-evergreen spreading shrub, to 12 ft., similar to Q. cinerea: lvs. oblong to linear-oblong, entire or coarsely toothed, tomentulose beneath, glabrous at length: acorn subglobose, 1/2in. high; maturation annual. N. C. to Fla. S.S. 8:404.—Q. Pyrami, Kotschy. Variety of Q. AEgilops, with the lvs. less deeply and very irregularly lobed: cup embracing one-third of the acorn, with the lower scales loosely appressed, the upper ones recurved. Asia Minor.—Q. reticulata, Humb. & Bonpl. Half-evergreen tree, to 30 ft., or shrub: lvs. oval or obovate, spiny-dentate toward the apex, bluish green, tomentose and reticulate beneath, 1-5 in. long: fr. in slender-stalked spikes; cup with appressed scales. Ariz. and New Mex. to Mex. S.S. 8:390.—Q. rotunda, Hort.=Q. phillyreoides.—Q. sclerophylla, Hort., not Lindl. Sometimes Q. Pseudoturneri is cult. under this name. The true Q. sclerophylla, Lindl., belongs to Castanopsis, see C. sclerophylla, below.—Q. sericea, Willd. =Q. pumila.—Q. serrata, Thunb. (Q. acutissima, Carruthers). Half-evergreen tree: lvs. obovate-oblong to oblong, acute, serrate, light green and glabrous below, 2-8 in. long: fr. sessile; cup with large, spreading and recurved scales, embracing two-thirds of the nut. Korea, Japan. S.I.F. 1:26.—Q. Skinneri, Benth. Tree, to 70 ft.: lvs. slender-stalked, ovate to ovate-lanceolate, sinuately serrate with bristly teeth, glabrous, 3-6 in. long: fr. sessile; acorn subglobose, large. S. Mex., Guatemala. G.C. 1841:116.—Q. sutchuenensis, Franch.=Q.Engleriana.-Q. thalassica, Hance=Pasania thalassica.-Q. Turneri, Willd. Half-evergreen tree: lvs. oval to elliptic-ovate, rounded at base, with 6-8 pairs of lobes, pubescent at least on the midrib beneath, midrib pale green. Origin unknown.—Q. Turneri, Hort.=Q. Pseudoturneri.—Q. undulata, Torr. Small tree or shrub: allied to Q. Douglasii; with smaller, less deeply lobed, bluish green lvs. pubescent below, nut smaller. Colo. to Ariz. and Texas. S.S. 8: 385.—Q. Ungeri, Kotschy. Variety of Q. AEgilops: lvs. smaller, lobed: cup with recurved scales, not much shorter than acorn. Asia Minor.—Q. Veneris, Kern. Tree: branchlets pubescent: lvs. subcoriaceous, broadly oblong, with 6-8 pairs of small acutish teeth, pubescent beneath or nearly glabrous, 1 1/2-3 in. long: fr. nearly sessile; acorn embraced one-half by the hemispherical cup. Cyprus.—Q. Wilsonii, Seemen=Q. cleistocarpa.—Q. Wislizenii, DC. Evergreen tree, to 80 ft.: allied to Q. agrifolia: lvs. ovate to oblong- lanceolate, sinuately dentate or entire, glabrous, yellowish green beneath, 1-5 in. long: acorn embraced about one-half by the Cup. Colo. to Calif. and Texas. S.S. 8:406
  
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The oak is the emblem of [[County Londonderry]] in [[Northern Ireland]], as  a vast amount of the county was covered in forests of the tree until relatively recently.
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Note on Castanopsis. A recently concluded study of the Chinese oaks has enabled us to name these Chinese species of Castanopsis which had not yet been determined when the article on that genus was written, and has furthermore convinced us that several species usually referred to Pasania or Quercus must be included in Castanopsis.
  
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There is a [[proverb]], "Mighty oaks from little [[acorn]]s grow."
+
The following species of Castanopsis are known to be in cult.: C. ceratacantha, Rehd. & Wilson. Tree, to 50 ft.: branchlets densely villous: lvs. oblong-lanceolate to ovate-lanceolate, acuminate, obscurely toothed above the middle or entire, brownish villous-tomentose beneath, 4-6 in. long: frs. in stout spikes to 8 in. long, 1/4-1 in. across, fulvous-tomentulose, with stout prickles 1/4-1/2in. long and divided at the apex into several spreading spiny points; nuts 2-3, wholly inclosed. W. China.—C. chrysophylla, DC., see Vol. II, p. 682.—C. cuspidata, Schottky (Quercus cuspidata, Thunb. Pasania cuspidata, Oerst.). This species is already mentioned under Pasania, see p. 2479. The ovate pointed involucre is marked with 4 or 5 wavy concentric ridges of small tubercles and includes wholly the solitary nut. There are two varieties in cult.: var. latifolia, Rehd. & Wilson, with larger and broader lvs. to 4 1/2 in. long and to 2 1/2 in. broad; and var. variegata, Rehd. & Wilson, with small lvs. bordered by a broad, irregular, creamy white margin. G.C. II. 12:233.—C. Fargesii, Franch. Tree, to 100 ft.: branchlets glabrous: lvs. elliptic-oblong to lanceolate, acuminate, serrate above the middle, thinly and closely yellowish or grayish tomentulose beneath, finally nearly glabrous, 2-5 in. long: frs. in stout spikes to 6 in. long, about 3/4in. across, with stout, often reflexed fascicled spines, about 1/2in. long; nut usually solitary, wholly inclosed. Cent. China.—C. platyacantha, Rehd. & Wilson. Tree, to 80 ft.: branchlets glabrous: lvs. ovate-oblong to elliptic-oblong, acuminate, slightly toothed above the middle or entire, covered beneath, except the glabrous midrib, with a close fulvous tomentum, becoming paler the second year, 2 1/2-5 in. long: spikes short, 3-6- fruited: frs. about 1 in. across, grayish tomentulose, densely covered with short and stout fascicled prickles; nuts wholly inclosed, 1-3. W. China.—C. sclerophylla, Schottky (Q. sclerophylla, Lindl. Q. chinensis, Abel). Tree, to 60 ft.: lvs. oval to oblong-ovate or oblong, acuminate, serrate above the middle, glabrous, glaucescent beneath, 2 1/2-6 in. long: frs. in dense spikes with the peduncle to 4 in. long; involucre ovoid, with close concentric ridges of small tubercles, not wholly inclosing the solitary nut. E. and Cent.
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China.
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Many woods are connected to certain birth months, according to the Irish, and oak is the wood of June/July. However, in some variations, rosewood has been known to be June's wood {{Fact|date=February 2007}}.
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}}
  
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[[Raleigh, NC|Raleigh]], [[North Carolina]] has been nicknamed the "City of Oaks."
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==Gallery==
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{{photo-sources}}<!-- remove this line if there are already 3 or more photos in the gallery  -->
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The [[Romania national rugby union team]] is nicknamed ''The Oaks.''
 
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In [[Celtic mythology]] it is the tree of doors, believed to be a gateway between worlds, or a place where portals could be erected.
 
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Oak leaves are used to symbolize rank in the [[United States Armed Forces]]. A gold oak leaf indicates an O-4 ([[Major]] or [[LCDR|Lt. Commander]]), whereas a silver oak leaf indicates an O-5 ([[Lt. Colonel]] or [[Commander]]). Arrangements of oak leaves, acorns and sprigs indicate different branches of the [[United States Navy]] [[List of United States Navy staff corps|Staff corps]] officers.
 
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[[Derry]] in [[Northern Ireland]] is named after the [[Irish language|Irish]] word "Doire," meaning oak tree.
 
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==Historical note on Linnaean species==
 
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[[Carolus Linnaeus|Linnaeus]] described only five species of oak from eastern North America, based on general leaf form. These were White oak, ''Q. alba'', Chestnut oak, ''Q. montana'', Red oak, ''Q. rubra'', Willow oak, ''Q. phellos'', and Water oak, ''Q. nigra''. Because he was dealing with confusing leaf forms, the ''Q. prinus'' and ''Q. rubra'' specimens actually included mixed foliage of more than one species. For that reason, some taxonomists in the past proposed different names for these two species (''Q. montana'' and ''Q. borealis'', respectively), but the original Linnaean names have now been lectotypified with only the specimens in Linnaeus' herbarium that refer to the species the names are applied to now.
 
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==References and notes==
 
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<References/>
 
  
 
<gallery>
 
<gallery>
Line 101: Line 133:
 
Image:Spanish-moss-tree.jpg|[[Southern live oak]] with [[spanish moss]]
 
Image:Spanish-moss-tree.jpg|[[Southern live oak]] with [[spanish moss]]
 
</gallery>
 
</gallery>
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==References==
 +
*[[Standard Cyclopedia of Horticulture]], by L. H. Bailey, MacMillan Co., 1963
 +
<!--- xxxxx  *Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881925381  -->
 +
<!--- xxxxx  *American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432  -->
 +
<!--- xxxxx  *Sunset National Garden Book. Sunset Books, Inc., 1997. ISBN 0376038608  -->
  
 
==External links==
 
==External links==
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{{commonscat|Quercus}}
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*{{wplink}}
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* [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=1&taxon_id=127839 Flora of North America: ''Quercus'']
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* [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=2&taxon_id=127839 Flora of China: ''Quercus'']
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{{stub}}
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*[http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Quercus&SPECIES_XREF=&TAXON_NAME_XREF=&RANK= Flora Europaea: ''Quercus'']
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__NOTOC__
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*[http://www.bcgov.net/bftlib/oaktrees.htm Oak Trees of the Lowcountry (South Carolina) -- Beaufort County Library]
 
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[[Category:Fagaceae]]
 

Latest revision as of 12:13, 20 February 2010


Foliage and acorns of Pedunculate oak (Quercus robur)


Plant Characteristics
Habit   tree
Cultivation
Scientific Names

Fagaceae >

Quercus >



Read about Oak in the Standard Cyclopedia of Horticulture 

Oak. Plants of the genus Quercus (which see). The word is also applied to other plants to some extent, from resemblances in form of tree, in leaf, or in hardness of wood. In Australia, where there are no species of Quercus, the word oak is applied to the species of Casuarina, "from a fancied resemblance," as Maiden says, "of the wood of casuarinas to that of oak." Other plants in Australia are sometimes known as oaks. The silk oak of florists is Grevillea robusta. The Jerusalem oak is Chenopodium Botrys, probably from the shape of the leaves. Poison oak is Rhus Toxicodendron, and related species.


The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.


This article is about oaks (Quercus). For other uses of "Oak" or "Oak tree", see Oak (disambiguation)

The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus, and some related genera, notably Cyclobalanopsis and Lithocarpus. The genus is native to the northern hemisphere, and includes deciduous and evergreen species extending from cold latitudes to tropical Asia and the Americas.

Oaks have spirally arranged leaves, with a lobed margin in many species; some have serrated leaves or entire leaves with a smooth margin. The flowers are catkins, produced in spring. The fruit is a nut called an acorn, borne in a cup-like structure known as a cupule; each acorn contains one seed (rarely two or three) and takes 6-18 months to mature, depending on species. The "live oaks" (oaks with evergreen leaves) are not a distinct group, instead with their members scattered among the sections below.


Read about Oak in the Standard Cyclopedia of Horticulture 

Quercus (ancient Latin name). Fagaceae. Oak. Ornamental trees, rarely shrubs, grown chiefly for their handsome foliage and interesting habit; many species are important timber trees. See Oak.

Deciduous or evergreen trees, rarely shrubby: winter buds with usually many imbricate scales: lvs. alternate, short-petioled, with deciduous stipules, pen- ninerved, serrate, lobed or pinnatifid, rarely entire: fls. monoecious; the staminate in slender, pendulous catkins with 4-7-parted calyx and 4-12, usually 6, stamens; pistillate in 1- to many-fld. spikes in the axils of the young lvs., each fl. consisting of an incompletely 3-, or rarely 4-5-celled ovary, surrounded by imbricate bracts; style short or elongated, dilated above and stigmatic on the inner face: fr. a 1-seeded subglobose to oblong nut, surrounded at the base or sometimes almost inclosed by a cup-like involucre.—More than 200 species are known, distributed through the colder and temperate regions of the northern hemisphere and in the mountains of the tropics. The numerous species are usually divided into 3 subgenera. The species of the subgenus Cyclobalanopsis which has the scales of the cup connate into concentric rings are all Asiatic. The American species belong to Lepidobalanus (balanos is Greek for acorn) and to Erythrobalanus. In the former, comprising the white oak tribe, the acorns mature the first year (Fig. 3304). In the latter, comprising the black oaks, the acorns mature the second year (Fig. 3305). Besides the 200 species, about 40 hybrids have been recorded. Pasania, often included under Quercus, is now usually considered a distinct genus, which see. The latest monograph of the whole genus is by A. DeCandolle in "Prodromus," vol. 16, 2, pp. 1-108 (1864-1868). Important illustrated works on American oaks are A. Michaux, "Histoire des Chenes de l'Amerique" (1801), with 36 plates; Kellogg and Greene. "Illustrations of West American Oaks" (1889), with 37 plates; Sargent, "Silva of North America," vol. 8 (1895), with 82 plates, and Liebmann, "Chenes de l'Amerique Tropicale" (1869), with 47 plates. Most of the European and west Asian oaks are figured in Kotschy "Eichen Europas und des Orients" (1862), with 40 colored plates. For comparative illustrations of lvs. see M.D. 1900, p. 32; R.B. 27, p. 61; G.W. 7, pp. 570, 571, 573; for those of frs. see M.D. 1900, p. 40; R.B. 27, p. 109.

The oaks are mostly trees, often tall with massive trunk and stout spreading limbs, with medium-sized, short-petioled leaves, usually more or less lobed, dentate or serrate, rarely entire, with inconspicuous flowers, the staminate ones in slender pendulous catkins and with fruits or "acorns" consisting of a globular to oblong nut inclosed at the base only, rarely wholly or nearly wholly, by a cup-like involucre. The oaks comprise some of the most important forest trees of the northern hemisphere. The wood of most species is strong, tough, hard and durable, and highly valued for many purposes, especially ship-building, construction, for furniture, and in the manufacture of wagons, tools and many other articles. The bark of some species, in America that of Q. velutina and Q. Prinus, is used for tanning leather. Cork is obtained from the bark of Q. Suber and Q. occidentalis in southern Europe. The bark of a few species has also been employed in medicine. The acorns of several species are edible, in America especially those of Q. Prinus, Q. Emoryi and Q. lobata; in Europe those of Q. Ilex var. Ballota and Q. Egilops; in Japan those of Q. glauca; in many European countries the acorns of all species are an important food for hogs. In eastern Asia a silkworm feeds on the leaves of different species. A parasitic insect living on Q. coccifera in southern Europe and northern Africa yields a scarlet dye. Galls caused by the puncture of certain insects are used for tanning and dyeing and are now chiefly obtained from Q. Ilex var. infectoria in western Asia. Some of the above-mentioned species are described only in the supplementary list, page 2890.

The deciduous species are mostly hardy North, while of the evergreen ones none seems to be hardy farther north than Washington, D.C.; some half-evergreen oaks, as Q. Pseudoturneri and Q. macedonica, will probably prove hardy in the vicinity of New York.

Most of the oaks are stately trees of noble and majestic habit with stout, wide-spreading branches; some, as Q. alba, Q. Garryana, Q. vir- giniana, and Q. chrysolepis, often cover a space more than 100 feet in diameter; others, as Q. macrocarpa, Q. montana and Q. velutina, have a more oval, round- topped head, while Q. palustris and Q. imbricaria form symmetrical broad pyramids. A very few hardy species are shrubs, generally called scrub oaks, as Q. prinoides and Q. ilicifolia. Oaks rank among our most valuable park and avenue trees, and are as beautiful when grown as single trees as they are when grouped together and forming groves and woods. As avenue trees, Q. palustris, Q. rubra, Q. coccinea. Q. imbricaria and Q. Phellos are among the best, the last- named when medium-sized trees are desired; in the southern states, Q. laurifolia, Q. nigra, and the evergreen Q. virginiana are preferred. The shrubby species, like Q. prinoides and Q. ilicifolia, may be used for covering rocky hillsides and dry ridges.

Oak leaves are always beautiful. They have many shades of green; especially attractive are some with leaves of contrasting colors, the under side being silvery white, the upper one dark green, as in Q. Muhlenbergii, Q. macrocarpa, Q. Prinus, and some foreign evergreen species. In many oaks the leaves show a handsome pink or crimson color when unfolding, and some species assume brilliant autumnal tints. Especially beautiful in autumn are Q. coccinea and Q. palustris, with the foliage turning brilliant scarlet; Q. rubra, Q. imbricaria, and Q. Prinus, which turn bright or dark red; Q. alba, violet or vinous purple; Q. lyrata, scarlet or orange; Q. Phellos, pale yellow; Q. montana, orange or orange- brown; Q. falcata and Q. ilicifolia, orange-brown or yellow; Q. stellata and Q. nigra, brown or dull orange. Some of the foreign species, like Q. sessiliflora and also Q. Robur, Q. Cerris, Q. lanuginosa, Q. glandulifera, and others, retain the green color until late in fall. Besides our native evergreen species, the Japanese Q. acuta, Q. myrsinaefolia, and Q. glauca are among the best evergreen oaks for cultivation in the South; the European Q. Ilex and Q. Suber are also handsome evergreen trees.

Generally the oaks grow best in a moderately moist rich soil, including heavy clay; some, as Q. bicolor, Q. nigra, Q. alba, Q. Phellos, Q. falcata, and Q. virginiana, prefer moister situations and grow naturally in low and often even in swampy ground; while others, especially the red oaks, like Q. rubra, Q. coccinea, Q. imbricaria, Q. marilandica, Q. montana. and Q. stellata, grow well in drier, rocky or sandy soil, and the scrub oaks on dry and barren soil. The black and red oaks especially the pin oak, are usually easily transplanted and large trees are moved successfully, while the white oaks are more particular and only younger nursery- grown trees can be safely transplanted.

Oaks are propagated usually by seeds sown immediately after gathering in fall; this is especially necessary with Q. alba. Q. virginiana, and some other white oaks which sprout as soon as they are ripe; but only the root is produced in fall, while the stem does not appear until the following spring. The seeds of red and black oaks, and also of Q. Robur, if not sown at once should be stratified and sown early in spring. Acorns should be packed in earth, moss, or sawdust when shipped for a great distance. Varieties are usually grafted on potted stock in the greenhouse in early spring or sometimes in August. As a stock Q. Robur is preferred, but Q. rubra, Q. velutina, and Q. montana are also employed. It is probably safer to graft varieties of white and of red oak each on stock of the same group. The evergreen species are sometimes increased by layers and also by cuttings.

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Cultivation

Oak catkins are made up of small, yellowish-green flowers. Acorns appear after the female flowers are fertilized in spring. They are typically brown, tan, yellow, light green, deep green or grayish green. Oaks grow slowly and usually do not bear acorns until they are about 20 years old. Acorns require stratification to stimulate sprouting. Most white oaks need immediate stratification; species such as the Chestnut oak (Quercus montana) will sprout a root upon falling and must have a suitable substrate for immediate rooting. Many red oak acorns can be stratified for up to two years before sprouting. The life span of oaks typically ranges from 200 to 600 years, with a few species reaching 1,000 years.

Propagation

Pests and diseases

Sudden Oak Death (Phytophthora ramorum) is a water mould that can kill oaks within just a few weeks. Oak Wilt, caused by the fungus Ceratocystis fagacearum (a fungus closely related to Dutch Elm Disease), is also a lethal disease of some oaks, particularly the red oaks (the white oaks can be infected but generally live longer). Other dangers include wood-boring beetles, as well as root rot in older trees which may not be apparent on the outside, often only being discovered when the trees come down in a strong gale. Oaks are used as food plants by the larvae of Lepidoptera species.

Species

The genus is divided into a number of sections:

  • Sect. Quercus (synonyms Lepidobalanus and Leucobalanus), the oaks of Europe, Asia and North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless. Leaves mostly lack a bristle on lobe tips, which are usually rounded.
  • Sect. Mesobalanus, the Hungarian oak and its relatives of Europe and Asia. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. Quercus and sometimes included in it).
  • Sect. Cerris, the Turkey oak and its relatives of Europe and Asia. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
  • Sect. Protobalanus, the Canyon live oak and its relatives, in southwest United States and northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
  • Sect. Lobatae (synonym Erythrobalanus), the red oaks of North America, Central America and northern South America. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with spiny bristles at the lobe tip.

Full list of Quercus species

A hybrid white oak, possibly Quercus stellata × Q. muhlenbergii

Hybrids are common in oaks but usually only between species within the same section; no verified inter-section hybrids are known, except between species of sections Quercus and Mesobalanus, where several occur.

The genus Cyclobalanopsis, here treated as a distinct genus following the Flora of China, is often included within Quercus as a distinct subgenus.


Read about Oak in the Standard Cyclopedia of Horticulture 

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References

External links

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