Difference between revisions of "Oak" - New World Encyclopedia

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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'' (from [[Latin]] "oak tree"), 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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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'' (from [[Latin]] "oak tree"), which are listed in the [[List of Quercus species]], 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 [[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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The genus is divided into a number of sections:
 
The genus is divided into a number of sections:
 
*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.
 
*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.
*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. ''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 hairless acorn shell (closely related to sect. ''Quercus'' and sometimes included in it).
 
*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.
 
*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.
 
*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.
 
*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.
*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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*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.   
 
    
 
    
  
 
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[[List of Quercus species|'''List of ''Quercus'' species''']]
[[List of Quercus species|'''Full list of ''Quercus'' species''']]
 
  
 
[[Image:Quercus stellata.jpg|thumb|A hybrid white oak, possibly ''[[Post oak|Quercus stellata]]'' × ''[[Chinkapin oak|Q. muhlenbergii]]'']]
 
[[Image:Quercus stellata.jpg|thumb|A hybrid white oak, possibly ''[[Post oak|Quercus stellata]]'' × ''[[Chinkapin oak|Q. muhlenbergii]]'']]
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==Uses==
 
==Uses==
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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Oak wood has a density of about 0.75 g/cm³, great strength and hardness, and is very resistant to insect and fungal attack because of its high tannin content. It also has very attractive grain markings, particularly when quarter-sawn. Wide, [[quarter-sawn]] boards of oak have been prized since the [[Middle Ages]] for use in interior panelling of prestigious buildings such as the debating chamber of the [[British House of Commons]] in [[London]], [[England]], and in the construction of fine furniture. Oak wood, from ''Quercus robur'' and ''Q. petraea'', was used in Europe for the construction of ships until the 19th century, and was the principal timber used in the construction of European [[timber framing|timber-framed]] buildings. Today oak[[wood]] is still commonly used for [[furniture]] making and flooring, timber frame buildings, and for veneer production. [[Barrel (storage)|Barrel]]s in which red [[wine]]s, [[sherry]], [[brandy]] and spirits such as [[Scotch whisky]] and [[Bourbon whiskey]] are [[Aging barrel|aged]] are made from European and American oak. The use of [[oak (wine)|oak in wine]] can add many different dimensions to wine based on the type and style of the oak. Oak barrels, which may be charred before use, contribute to the color taste and aroma, of the contents, imparting a desirable oaky [[vanillin]] flavour to these drinks. The great dilemma for wine producers is to choose between French and American oakwoods. French oaks (''Quercus robur'', ''Q. petraea'')  give the wine greater refinement and are chosen for best wines since they increase the price compared to those aged in American oak wood. <ref name="larazon">{{es}} [http://www.larazon.es/noticias/noti_viv33894.htm ''La crianza del vino''] ''La Razón'' 23 de Agosto de 2007</ref> American oak contributes greater texture and resistance to ageing, but produces more violent wine bouquets.<ref name="larazon" /> Oak wood chips are used for [[smoking (cooking)|smoking]] fish, meat, [[cheese]]s<ref>http://www.williamsdeli.co.uk/product_info.php?cPath=66&products_id=256&osCsid=6f34dc1a878e28ab056ea5482a70e355</ref> <ref>http://www.swaledalecheese.co.uk/cheese.htm</ref> and other foods.
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[[Image:Sherry cellar, Solera system, 2003.jpg|thumb|[[Sherry]] maturing in oak barrels]]
  
The bark of ''Quercus suber'', or [[Cork oak]], is used 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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[[Image:Cork oak trunk section.jpg|thumb|A section of the trunk of a cork oak, ''Quercus suber'']]
 
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The bark of ''Quercus suber'', or [[Cork oak]], is used 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. 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 the [[deciduous]] [[Pedunculate Oak]] ''Quercus robur'' and [[Sessile Oak]] ''Quercus petraea'' account for most of the European oak production, but [[live oak|evergreen species]], such as [[Holm oak]] ''Quercus ilex'', and [[Cork oak]] ''Quercus suber'' also produce valuable timber.
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]].
 
  
 
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.
 
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.
  
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]].
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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]].{{Fact|date=July 2007}}
 
 
 
 
  
 
==Diseases and pests==
 
==Diseases and pests==
[[Sudden Oak Death]] ''(Phytophthora ramorum)'' is a [[water mold]] 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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[[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]]. [[Oak apple]]s are [[gall]]s on oaks made by the [[gall wasp]]. The female [[kermes (genus)|kermes]] [[scale insect|scale]] causes galls to grow on [[kermes oak]]. Oaks are used as food plants by the [[larva]]e of [[Lepidoptera]] species.
 
*''See also [[list of Lepidoptera which feed on Oaks]]''
 
*''See also [[list of Lepidoptera which feed on Oaks]]''
  
K4t13 + J355
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Also another pest would be the [[Gypsy moth]]. The [[Gypsy Moth]] is dominant in North America and there are many concerns of the loss of economically critical and ecologically dominant Oak species.
  
'''[[8FF1!]]'''
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==Toxicity==
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The leaves and acorns of the Oak tree are poisonous to horses in large amounts, due to the toxin [[tannic acid]], and causes kidney damage and [[gastroenteritis]]. Additionally, once horses have a taste for the leaves and acorns, they may seek them out. Therefore, horse owners are encouraged to fence out Oak trees from their pasture, especially if forage is scarce. Symptoms of poisoning include lack of appetite, depression, constipation, diarrhea (which may contain blood), blood in urine, and [[equine colic|colic]].
  
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==Cultural significance==
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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, [[Estonia]], [[France]], [[Germany]], [[Lithuania]], [[Poland]], the [[United States]] and [[Wales]].
  
G4881 + 1ZZY
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[[Image:Coat of arms of Estonia.svg|right|thumb|Oak leaves on the [[coat of arms of Estonia]]]]
  
'''[[8FF1!]]'''
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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.
  
==Cultural significance==
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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}}.
 
The oak is a common [[symbol]] of [[Virtue|strength]] and [[endurance]] and has been chosen as the [[national tree]] of [[England]], [[France]], [[Germany]], the [[United States]] and [[Wales]].
 
  
[[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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In [[Classical mythology]] the oak was a symbol of [[Zeus]] and his sacred tree. An example is the oracle of [[Dodona]], which in prehistory consisted solely of a holy oak.
  
 
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.
 
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.
  
In [[Classical mythology]] the oak was a symbol of [[Zeus]] and his sacred tree.   
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The Oak tree is traditionally sacred to [[Serbs]] and is widely used throughout [[Serbia]] on national and regional symbols both old and new.   
  
 
Several individual oak trees, such as the [[Royal Oak (tree)|Royal Oak]] in Britain and the [[Charter Oak]] in the United States, are of great historical or cultural importance; for a list of important oaks, see [[:Category:Individual oak trees|Individual oak trees]].
 
Several individual oak trees, such as the [[Royal Oak (tree)|Royal Oak]] in Britain and the [[Charter Oak]] in the United States, are of great historical or cultural importance; for a list of important oaks, see [[:Category:Individual oak trees|Individual oak trees]].
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The [[Romania national rugby union team]] is nicknamed ''The Oaks.''
 
The [[Romania national rugby union team]] is nicknamed ''The Oaks.''
  
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  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.
  
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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Oak leaves were added to the [[Knight's Cross of the Iron Cross#Knight.27s Cross with Oak Leaves .28mit Eichenlaub.29|Iron Cross]] for added status.
  
 
==Historical note on Linnaean species==
 
==Historical note on Linnaean species==
[[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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[[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.
  
==References and notes==
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==References==
<References/>
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{{reflist}}
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* Byfield, Liz (1990) ''An oak tree'', Collins book bus, London : Collins Educational, ISBN 0-00-313526-8 
 +
* Logan, William B. (2005) ''Oak : the frame of civilization'', New York ; London : W.W. Norton, ISBN 0-393-04773-3 
 +
* Paterson, R.T. (1993) ''Use of trees by livestock'', '''5''':  ''Quercus'', Chatham : Natural Resources Institute, ISBN 0-85954-365-X
 +
* Royston, Angela (2000) ''Life cycle of an oak tree'', Heinemann first library, Oxford : Heinemann Library, ISBN 0-431-08391-6
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* Savage, Stephen (1994) ''Oak tree'', Observing nature series, Hove : Wayland, ISBN 0-7502-1196-2 
 +
* Tansley, Arthur G., Sir (1952) ''Oaks and oak woods'', Field study books, London : Methuen, 50 p.
  
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==Gallery==
 
<gallery>
 
<gallery>
 
Image:Raunkiaer.jpg|A [[Pedunculate oak]] in [[Denmark]]
 
Image:Raunkiaer.jpg|A [[Pedunculate oak]] in [[Denmark]]
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Image:Oakbark.jpg|Bark of ''[[Quercus robur]]''
 
Image:Oakbark.jpg|Bark of ''[[Quercus robur]]''
 
Image:Spanish-moss-tree.jpg|[[Southern live oak]] with [[spanish moss]]
 
Image:Spanish-moss-tree.jpg|[[Southern live oak]] with [[spanish moss]]
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Image:Quercus mongolica mongolian oak MN 2007.JPG|''Quercus mongolica'' Mongolian Oak in [[Minnesota Landscape Arboretum]]
 
</gallery>
 
</gallery>
  
 
==External links==
 
==External links==
{{commonscat|Quercus}}
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* [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=1&taxon_id=127839 Flora of North America: ''Quercus'']
* [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=127839 Flora of North America: Quercus]. Retrieved November 7, 2007.
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* [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=2&taxon_id=127839 Flora of China: ''Quercus'']
* [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=127839 Flora of China: Quercus]. Retrieved November 7, 2007.
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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'']
*[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]. Retrieved November 7, 2007.
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*[http://www.bcgov.net/bftlib/oaktrees.htm Oak Trees of the Lowcountry (South Carolina) — Beaufort County Library]
*[http://www.bcgov.net/bftlib/oaktrees.htm Oak Trees of the Lowcountry (South Carolina)—Beaufort County Library]. Retrieved November 7, 2007.
 
  
 
[[Category:Life sciences]]
 
[[Category:Life sciences]]
 
[[Category:Plants]]
 
[[Category:Plants]]
  
{{credit|133233424}}
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{{credit|Oak|172505839}}

Revision as of 22:33, 19 November 2007

Oaks
Foliage and acorns of Quercus robur
Foliage and acorns of Quercus robur
Scientific classification
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Fagales
Family: Fagaceae
Genus: Quercus
L.
Species

See List of Quercus species

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 (from Latin "oak tree"), which are listed in the List of Quercus species, 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.

Classification

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 hairless acorn shell (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.


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.

Uses

Oak wood has a density of about 0.75 g/cm³, great strength and hardness, and is very resistant to insect and fungal attack because of its high tannin content. It also has very attractive grain markings, particularly when quarter-sawn. Wide, quarter-sawn boards of oak have been prized since the Middle Ages for use in interior panelling of prestigious buildings such as the debating chamber of the British House of Commons in London, England, and in the construction of fine furniture. Oak wood, from Quercus robur and Q. petraea, was used in Europe for the construction of ships until the 19th century, and was the principal timber used in the construction of European timber-framed buildings. Today oakwood is still commonly used for furniture making and flooring, timber frame buildings, and for veneer production. Barrels in which red wines, sherry, brandy and spirits such as Scotch whisky and Bourbon whiskey are aged are made from European and American oak. The use of oak in wine can add many different dimensions to wine based on the type and style of the oak. Oak barrels, which may be charred before use, contribute to the color taste and aroma, of the contents, imparting a desirable oaky vanillin flavour to these drinks. The great dilemma for wine producers is to choose between French and American oakwoods. French oaks (Quercus robur, Q. petraea) give the wine greater refinement and are chosen for best wines since they increase the price compared to those aged in American oak wood. [1] American oak contributes greater texture and resistance to ageing, but produces more violent wine bouquets.[1] Oak wood chips are used for smoking fish, meat, cheeses[2] [3] and other foods.

Sherry maturing in oak barrels
A section of the trunk of a cork oak, Quercus suber

The bark of Quercus suber, or Cork oak, is used to produce wine stoppers (corks). This species grows in the Mediterranean Sea region, with Portugal, Spain, Algeria and Morocco producing most of the world's supply. Of the North American oaks, the Northern red oak 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 the deciduous Pedunculate Oak Quercus robur and Sessile Oak Quercus petraea account for most of the European oak production, but evergreen species, such as Holm oak Quercus ilex, and Cork oak Quercus suber also produce valuable timber.

The bark of the White Oak is dried and used in medical preparations. Oak bark is also rich in tannin, and is used by tanners for tanning leather. Acorns are used for making flour or roasted for acorn coffee. Oak galls were used for centuries as the main ingredient in manuscript ink, harvested at a specific time of year.

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.[citation needed]

Diseases and pests

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. Oak apples are galls on oaks made by the gall wasp. The female kermes scale causes galls to grow on kermes oak. Oaks are used as food plants by the larvae of Lepidoptera species.

  • See also list of Lepidoptera which feed on Oaks

Also another pest would be the Gypsy moth. The Gypsy Moth is dominant in North America and there are many concerns of the loss of economically critical and ecologically dominant Oak species.

Toxicity

The leaves and acorns of the Oak tree are poisonous to horses in large amounts, due to the toxin tannic acid, and causes kidney damage and gastroenteritis. Additionally, once horses have a taste for the leaves and acorns, they may seek them out. Therefore, horse owners are encouraged to fence out Oak trees from their pasture, especially if forage is scarce. Symptoms of poisoning include lack of appetite, depression, constipation, diarrhea (which may contain blood), blood in urine, and colic.

Cultural significance

The oak is a common symbol of strength and endurance and has been chosen as the national tree of England, Estonia, France, Germany, Lithuania, Poland, the United States and Wales.

Oak leaves on the coat of arms of Estonia

In Celtic mythology it is the tree of doors, believed to be a gateway between worlds, or a place where portals could be erected.

Thor's Oak was a sacred tree of the Germanic Chatti tribe. Its destruction marked the Christianisation of the heathen tribes by the Franks[citation needed].

In Classical mythology the oak was a symbol of Zeus and his sacred tree. An example is the oracle of Dodona, which in prehistory consisted solely of a holy oak.

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 examples from the Bible.

The Oak tree is traditionally sacred to Serbs and is widely used throughout Serbia on national and regional symbols both old and new.

Several individual oak trees, such as the Royal Oak in Britain and the Charter Oak in the United States, are of great historical or cultural importance; for a list of important oaks, see Individual oak trees.

Iowa has designated the oak as its official state tree in 1961, and the White Oak is the state tree of Connecticut, Illinois and Maryland.

"Ambrosian Oaks" set to the Finlandia Hymn is the school song of St. Ambrose University in Davenport, Iowa.

The oak is the emblem of County Londonderry in Northern Ireland, as a vast amount of the county was covered in forests of the tree until relatively recently. The name of the county comes from the city of Derry, which originally in Irish was known as Doire meaning oak.

There is a proverb, "Mighty oaks from little acorns grow." Another is: "Every majestic oak tree was once a nut who stood his ground."

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 [citation needed].

Raleigh, North Carolina has been nicknamed the "City of Oaks."

The Romania national rugby union team is nicknamed The Oaks.

Oak leaves symbolize rank in the United States Armed Forces. A gold oak leaf indicates an O-4 (Major or Lt. Commander), whereas a silver oak leaf indicates an O-5 (Lt. Colonel or Commander). Arrangements of oak leaves, acorns and sprigs indicate different branches of the United States Navy Staff corps officers.

Oak leaves were added to the Iron Cross for added status.

Historical note on Linnaean species

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.

References
ISBN links support NWE through referral fees

  • Byfield, Liz (1990) An oak tree, Collins book bus, London : Collins Educational, ISBN 0-00-313526-8
  • Logan, William B. (2005) Oak : the frame of civilization, New York ; London : W.W. Norton, ISBN 0-393-04773-3
  • Paterson, R.T. (1993) Use of trees by livestock, 5: Quercus, Chatham : Natural Resources Institute, ISBN 0-85954-365-X
  • Royston, Angela (2000) Life cycle of an oak tree, Heinemann first library, Oxford : Heinemann Library, ISBN 0-431-08391-6
  • Savage, Stephen (1994) Oak tree, Observing nature series, Hove : Wayland, ISBN 0-7502-1196-2
  • Tansley, Arthur G., Sir (1952) Oaks and oak woods, Field study books, London : Methuen, 50 p.

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