Editing Oak (section)

=== Taxonomy ===

{{See also|List of Quercus species}}

==== Taxonomic history ====

The genus ''Quercus'' was [[circumscription (taxonomy)|circumscribed]] by [[Carl Linnaeus]] in the first edition of his 1753 ''[[Species Plantarum]]''.<ref>{{cite journal |last1=Pardo |first1=Francisco M. Vázquez |last2=Maqueda |first2=Soledad Ramos |last3=Pérez |first3=Esperanza Doncel |title=''Quercus ilex'' L. and ''Quercus rotundifolia'' Lam.: Two Different Species |journal=International Oaks |issue=13 |year=2002 |pages=9–14 |url=https://www.internationaloaksociety.org/sites/default/files//files/IO/IOS%20Journal%20%2313/International%20Oaks%20No.%2013%20-%20Quercus%20ilex%20L.%20and%20Quercus%20rotundifolia%20Lam.-%20Two%20Different%20Species%20-%20Franciso%20M.%20V%C3%A1zquez%20Pardo%2C%20Soledad%20Ramos%20Maqueda%2C%20Esperanza%20Doncel%20P%C3%A9rez.pdf}}</ref> He described 15 species within the new genus, providing type specimens for 10 of these, and giving names but no types for ''[[Quercus cerris|Q.&nbsp;cerris]]'', ''[[Quercus coccifera|Q.&nbsp;coccifera]]'', ''[[Quercus ilex|Q.&nbsp;ilex]]'', ''[[Quercus smilax|Q.&nbsp;smilax]]'', and ''[[Quercus suber|Q.&nbsp;suber]]''.<ref>{{cite journal |last1=Iamonico |first1=Duilio |last2=Peruzzi |first2=Lorenzo |title=Lectotypification of Linnaean Names in the Genus ''Quercus'' (Fagaceae) |journal=Taxon |volume=62 |issue=5 |year=2013 |pages=1041–1045 |doi=10.12705/625.5 |jstor=taxon.62.5.1041|bibcode=2013Taxon..62.1041I }}</ref> He chose ''[[Quercus robur|Q.&nbsp;robur]]'', the pedunculate oak, as the [[type species]] for the genus.<ref>{{cite journal |last1=Nixon |first1=Kevin C. |last2=Carpenter |first2=James M. |last3=Stevenson |first3=Dennis W. |title=The PhyloCode is fatally flawed, and the 'Linnaean' system can easily be fixed |journal=The Botanical Review |volume=69 |issue=1 |year=2003 |pages=111–120 |doi=10.1663/0006-8101(2003)069[0111:TPIFFA]2.0.CO;2 |s2cid=43477057 |url=http://lamarck.unl.edu/systematics/papers-pdf/BotRev691_111-120.pdf}}</ref>

A 2017 classification of ''Quercus'', based on multiple molecular phylogenetic studies, divided the genus into two [[subgenera]] and eight [[Section (botany)|sections]]:<ref name=DenkGrimManoDeng17>{{Citation |last1=Denk |first1=Thomas |last2=Grimm |first2=Guido W. |last3=Manos |first3=Paul S. |last4=Deng |first4=Min |last5=Hipp |first5=Andrew L. |display-authors=3 |title=Oaks Physiological Ecology. Exploring the Functional Diversity of Genus ''Quercus'' L |series=Tree Physiology |date=2017 |volume=7 |editor1-last=Gil-Pelegrín |editor1-first=Eustaquio |editor2-last=Peguero-Pina |editor2-first=José Javier |editor3-last=Sancho-Knapik |editor3-first=Domingo |contribution=An Updated Infrageneric Classification of the Oaks: Review of Previous Taxonomic Schemes and Synthesis of Evolutionary Patterns |pages=13–38 |publication-place=Cham. |publisher=Springer International Publishing |doi=10.1007/978-3-319-69099-5_2 |isbn=978-3-319-69099-5 |contribution-url=https://doi.org/10.1007/978-3-319-69099-5_2 |mode=cs1}}</ref>

*Subgenus ''Quercus'' – the New World clade (or high-latitude clade), mostly native to North America
**Section ''Lobatae'' <small>Loudon</small> – North American red oaks
**Section ''Protobalanus'' <small>(Trelease) O.Schwarz</small> – North American intermediate oaks
**Section ''Ponticae'' <small>Stef.</small> – with a [[disjunct distribution]] between western [[Eurasia]] and western North America
**Section ''Virentes'' <small>Loudon</small> – American southern live oaks
**Section ''Quercus'' – white oaks from North America and Eurasia
*Subgenus ''Cerris'' <small>Oerst.</small>  – the Old World clade (or mid-latitude clade), exclusively native to Eurasia
**Section ''Cyclobalanopsis'' <small>Oerst.</small> – cycle-cup oaks of East Asia
**Section ''Cerris'' <small>Dumort.</small> – cerris oaks of subtropical and temperate Eurasia and North Africa
**Section ''Ilex'' <small>Loudon</small> – ilex oaks of tropical and subtropical Eurasia and North Africa
<!--note --- these sections are clearly marked on the cladogram below-->

The subgenus division supports the evolutionary diversification of oaks among two distinct clades: the Old World clade (subgenus ''Cerris''), including oaks that diversified in Eurasia; and the New World clade (subgenus ''Quercus''), oaks that diversified mainly in the Americas.<ref name=":0">{{Cite journal |last1=Manos |first1=Paul S. |last2=Zhou |first2=Zhe-Kun |last3=Cannon |first3=Charles H. |year=2001 |title=Systematics of Fagaceae: Phylogenetic Tests of Reproductive Trait Evolution |journal=International Journal of Plant Sciences |volume=162 |issue=6 |pages=1361–1379 |doi=10.1086/322949 |jstor=10.1086/322949 |bibcode=2001IJPlS.162.1361M |s2cid=85925622}}</ref><ref name="Manos Hipp 2021">{{cite journal |last1=Manos |first1=Paul S. |last2=Hipp |first2=Andrew L. |title=An Updated Infrageneric Classification of the North American Oaks (''Quercus'' Subgenus ''Quercus''): Review of the Contribution of Phylogenomic Data to Biogeography and Species Diversity |journal=Forests |publisher=MDPI AG |volume=12 |issue=6 |date=2021-06-15 |issn=1999-4907 |doi=10.3390/f12060786 |page=786 |doi-access=free |bibcode=2021Fore...12..786M }}</ref>

==== Subgenus ''Quercus'' ====

{{main|Quercus subg. Quercus|l1=''Quercus'' subg. ''Quercus''}}

* Sect. ''Lobatae'' ([[Synonym (taxonomy)|synonym]] ''Erythrobalanus''), the [[Erythrobalanus|red oaks]] of North America, [[Central America]] and northern [[South America]]. [[Style (botany)|Style]]s are long; the acorns mature in 18 months and taste very bitter. The inside of the acorn shell appears woolly. The actual nut is encased in a thin, clinging, papery skin. The leaves typically have sharp lobe tips, with spiny bristles at the lobe.<ref name=DenkGrimManoDeng17/>
* Sect. ''Protobalanus'', the [[Protobalanus|canyon live oak and its relatives]], in the southwestern [[United States]] and northwest [[Mexico]]. Styles are short; the acorns mature in 18 months and taste very bitter. The inside of the acorn shell appears woolly. The leaves typically have sharp lobe tips, with bristles at the lobe tip.<ref name=DenkGrimManoDeng17/>
* Sect. ''Ponticae,'' a disjunct including just two species. Styles are short, and the acorns mature in 12 months. The leaves have large [[stipule]]s, high secondary veins, and are highly toothed.<ref name=DenkGrimManoDeng17/>
* Sect. ''Virentes,'' the southern live oaks of the Americas. Styles are short, and the acorns mature in 12 months. The leaves are evergreen or subevergreen.<ref name=DenkGrimManoDeng17/>
* Sect. ''Quercus'' (synonyms ''Lepidobalanus'' and ''Leucobalanus''), the [[Lepidobalanus|white oaks]] of [[Europe]], [[Asia]] and North America. Trees or shrubs that produce nuts, specifically acorns, as fruits. Acorns mature in one year for annual trees and two years for biannual trees. Acorn is encapsulated by a spiny cupule as characterized by the family Fagaceae. Flowers in the ''Quercus'' genera produce one flower per node, with three or six styles, as well as three or six [[Ovary (botany)|ovaries]], respectively. The leaves mostly lack a bristle on their lobe tips, which are usually rounded. The type species is ''[[Quercus robur]]''.<ref name=DenkGrimManoDeng17/><ref>{{Cite book |last=Hitchcock |first=C. Leo |url=https://www.worldcat.org/oclc/1027726223 |title=Flora of the Pacific Northwest : an illustrated manual |publisher=University of Washington Press |others=Arthur Cronquist, David Giblin, Ben Legler, Peter F. Zika, Richard G. Olmstead |year=2018 |isbn=978-0-295-74289-2 |edition=Second |location=Seattle |pages=221 |oclc=1027726223}}</ref>

==== Subgenus ''Cerris'' ====

{{main|Quercus subg. Cerris|l1=''Quercus'' subg. ''Cerris''}}

The type species is ''Quercus cerris''.
* Sect. ''[[List of Quercus species#Section Cyclobalanopsis|Cyclobalanopsis]]'', the [[List of Quercus species#Section Cyclobalanopsis|ring-cupped oaks]] of eastern and southeastern Asia. These are evergreen trees growing {{convert|10|–|40|m|ft|0|abbr=off}} tall. They are distinct from subgenus ''Quercus'' in that they have acorns with distinctive cups bearing concrescent rings of scales; they commonly also have densely clustered acorns, though this does not apply to all of the species. Species of ''Cyclobalanopsis'' are common in the evergreen subtropical [[laurel forest]]s, which extend from southern Japan, southern Korea, and Taiwan across southern China and northern Indochina to the eastern Himalayas, in association with trees of the genus ''[[Castanopsis]]'' and the laurel family ([[Lauraceae]]).<ref name=DenkGrimManoDeng17/>
* Sect. ''Cerris'', the [[Cerris|Turkey oak and its relatives]] of Europe and Asia. Styles are long; acorns mature in 18 months and taste very bitter. The inside of the acorn's shell is hairless. Its leaves typically have sharp lobe tips, with bristles at the lobe tip.<ref name=DenkGrimManoDeng17/>
* Sect. ''[[List of Quercus species#Section Ilex|Ilex]]'', the Ilex oak and its relatives of Eurasia and northern [[Africa]]. Styles are medium-long; acorns mature in 12–24 months, appearing hairy on the inside. The leaves are evergreen, with bristle-like extensions on the teeth.<ref name=DenkGrimManoDeng17/>