Quercus subg. Cerris

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Quercus subg. Cerris
Quercus cerris.JPG
Quercus cerris (type species)
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fagales
Family: Fagaceae
Genus: Quercus
Subgenus: Quercus subg. Cerris
Oerst. [1]
Sections [1]
  • Quercus sect. CyclobalanopsisOerst.
  • Quercus sect. IlexLoudon
  • Quercus sect. CerrisDumort.

Quercus subgenus Cerris is one of the two subgenera into which the genus Quercus was divided in a 2017 classification (the other being subgenus Quercus). It contains about 140 species divided among three sections. It may be called the Old World clade or the mid-latitude clade; all species are native to Eurasia and North Africa.

Contents

Description

Like all species of Quercus, those of subgenus Cerris are trees or shrubs with acorn-like fruit in which a cup covers at least the base of the nut. Members of subgenus Cerris are distinguished from members of subgenus Quercus by few morphological features, their separation being largely determined by molecular phylogenetic evidence. The structure of the mature pollen is one feature that distinguishes the two subgenera: in subgenus Cerris, the small folds or wrinkles (rugulae) are visible or at most weakly obscured, whereas in subgenus Quercus, the rugulae are obscured by sporopollenin. [1]

The two subgenera are also distinguished to some extent by their different distributions. Subgenus Cerris is primarily Eurasian, with a few species in North Africa, and may be called the Old World clade or the mid-latitude clade. Subgenus Quercus occurs mainly in the Americas (although some species are also found in Eurasia and North Africa), and may be called the New World clade or the high-latitude clade. [1]

Taxonomy

Quercus subgenus Cerris was first established by Anders Sandøe Ørsted in 1867. However, his conception and that of later workers, who often reduced it to a section, was closer to the modern section Cerris than the wider circumscription that has resulted from molecular phylogenetic studies, in which the subgenus is one of two divisions of the genus Quercus, and includes three sections. [1]

Phylogeny

The following cladogram summarizes the relationships that Denk et al. used to draw up their 2017 classification: [1]

Quercus

subg. Quercus

subg. Cerris

sect. Cyclobalanopsis

sect. Ilex

sect. Cerris

Section Cyclobalanopsis

Quercus sect. Cyclobalanopsis was first established, as the genus Cyclobalanopsis, by Anders Sandøe Ørsted in 1867. [2] It was first reduced from a genus to a section by George Bentham and William Jackson Hooker in 1880. It has also been treated as a subgenus. Members may be called cycle-cup oaks, [1] or ring-cup oaks.

Like all species of Quercus, those of section Cyclobalanopsis are trees or shrubs with acorn-like fruit. The staminate flowers are arranged in groups of usually one to three, but sometimes up to seven, along the axis of the inflorescence. The ornamentation of the mature pollen is a distinguishing feature of the section: pollen grains have vertical folds (rugulae). The stalk that joins the perianth to the ovary (the perianthopodium) has three to five distinct rings. The 'cup' (cupule) around the base of acorn also has distinct rings formed from thin membranes (lamellae), which also distinguishes the section from other oaks. The leaves are evergreen. [1]

The section contains about 90 species native to tropical and subtropical Asia including the southern Himalayas. [1]

Section Ilex

Quercus sect. Ilex was first established by John Claudius Loudon in 1838. It has also been treated as a subgenus, under the name Quercus subg. HeterobalanusOerst., and as subsection. Members may be called ilex oaks. [1]

Like all species of Quercus, those of section Ilex are trees or shrubs with acorn-like fruit. The staminate flowers have four to six stamens. The ornamentation of the mature pollen is distinctive, consisting of wrinkles or folds (rugulae). The acorns mature either annually or after two years. The cup of the acorn has triangular scales, usually thin and membranous. The toothed leaves are evergreen with spines or bristles at the ends of the teeth. [1]

The section contains about 40 species native to Eurasia and North Africa. [1]

Section Cerris

Quercus section Cerris was first established by Barthélemy Charles Joseph Dumortier in 1829. It has been treated as a section under other names, including Quercus sect. ErythrobalanopsisOerst., Quercus sect. CastaneifoliaO.Schwarz, Quercus sect. ValloneaO.Schwarz, Quercus sect. Aegilops(Reichenb.) O.Schwarz and the illegitimate name Quercus sect. EucerrisOerst. Members may be called cerris oaks. [1]

Like all species of Quercus, those of section Cerris are trees or shrubs with acorn-like fruit. The staminate flowers have four to six stamens. The ornamentation of the mature pollen is distinctive, consisting of scattered small bumps (verrucate). The cup of the acorn has narrowly triangular scales, thickened and with a keel and elongated recurved tips. The leaf is toothed, typically with bristle-like extensions to the teeth. [1]

There are about 13 species in Eurasia and North Africa, [1] including the cork oak, Quercus suber , [3] an important source of cork for wine stoppers, [4] among other uses. It is the only oak section with a centre of diversity in the Western Palearctic. [5]

Conservation

The 2020 Red List of Oaks shows that within the species assessed across all eight sections of the genus Quercus, the sections Cyclobalanopsis and Ilex have the largest proportions of species put into the "critically endangered" category, representing the highest level of threat. [6] A large number of section Cyclobalanopsis species occur in China: the Flora of China states that 69 are native to China of which 43 are endemic. [7] China has the largest number of threatened oak species. [6]

Related Research Articles

<span class="mw-page-title-main">Oak</span> Tree or shrub in the genus Quercus

An oak is a hardwood tree or shrub in the genus Quercus of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisphere; it includes some 500 species, both deciduous and evergreen. Fossil oaks date back to the Middle Eocene. Molecular phylogeny shows that the genus is divided into Old World and New World clades, but many oak species hybridise freely, making the genus's history difficult to resolve.

<i>Quercus ilex</i> Oak tree species native to the Mediterranean

Quercus ilex, the evergreen oak, holly oak or holm oak is a large evergreen oak native to the Mediterranean region. It is a member of the Ilex section of the genus, with acorns that mature in a single summer.

<i>Quercus glauca</i> Species of oak tree

Quercus glauca, commonly called ring-cupped oak or Japanese blue oak, is a tree in the beech family (Fagaceae). It is native to eastern and southern Asia, where it is found in Afghanistan, Bhutan, China, northern and eastern India, southern Japan, Kashmir, Korea, Myanmar, Nepal, and Vietnam. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus coccifera</i> Species of tree

Quercus coccifera, the kermes oak, is an oak bush in the Ilex section of the genus. It has many synonyms, including Quercus calliprinos. It is native to the Mediterranean region and Northern African Maghreb, south to north from Morocco to France and west to east from Portugal to Cyprus and Turkey, crossing Spain, Italy, Libya, Balkans, and Greece, including Crete. The Kermes Oak was historically important as the food plant of Kermes scale insects, from which a red dye called crimson was obtained. The etymology of the specific name coccifera is related to the production of red cochineal (crimson) dye and derived from Latin coccum which was from Greek κόκκος, the kermes insect. The Latin -fera means 'bearer'.

<i>Quercus lamellosa</i> Species of tree

Quercus lamellosa is a species of oak (Quercus) native to the Himalaya and adjoining mountains from Tibet and Nepal east as far as Guangxi and northern Thailand, growing at altitudes of 1300–2500 m. The Lepcha of Sikkim call it book koong. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus franchetii</i> Species of oak tree

Quercus franchetii, commonly known as the zhui lian li evergreen oak, is a species of oak in the Ilex section of the genus, native to a wide area of eastern Asia. It is an oak native to China, northern Thailand and Vietnam, growing at altitudes between 800 and 2,600 metres.

Quercus sichourensis is a species of oak found only in Yunnan Province in China. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus phillyreoides</i> Species of plant

Quercus phillyreoides is a species of flowering plant in the genus Quercus, placed in subgenus Cerris and section Ilex. It is evergreen, withstands frost and can be grown in hardiness zone 7. It is native to southern China, the Ryukyu Islands, and Japan, and has been introduced to Korea.

<i>Quercus argyrotricha</i> Species of tree

Quercus argyrotricha is a rare Chinese species of trees in the beech family. It has been found only in Guizhou Province in southern China. The common name is Chinese for this species is gui zhou qing gang.

<i>Quercus edithiae</i> Species of oak tree

Quercus edithiae is a species of tree in the family Fagaceae and the "ring-cupped oak" sub-genus. It has been found in Vietnam and also in southern China, in the Provinces of Guangdong, Guangxi, and Hainan. In Vietnam it is called sồi editha. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus longinux</i> Species of oak tree

Quercus longinux is an uncommon Asian species of trees in the beech family Fagaceae. It has only been found in Taiwan. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus poilanei is an Asian species of tree in the family Fagaceae. It has been found in northern Indochina and also in the Province of Guangxi in southern China. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus saravanensis is an Asian species of tree in the beech family Fagaceae. It has been found in northern Indochina, and also in the Province of Yunnan in southwestern China. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus thorelii is an Asian species of tree in the beech family Fagaceae. The species is named after the French botanist Clovis Thorel. It has been found in Indochina and in southern China. It is placed in subgenus Cerris, section Cyclobalanopsis, the ring-cupped oaks.

Quercus xanthotricha is an Asian species of tree in the beech family Fagaceae. It has been found in Indochina and in southern China (Yunnan); the synonym Q. djiringensis suggests it may be distributed as far south as Di Linh in Lâm Đồng Province. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus petelotii is the accepted name of an endemic oak tree species in the beech family Fagaceae; there are no known sub-species. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus miyagii</i> Species of plant in the genus Quercus

Quercus miyagii is a species of oak native to the Ryukyu Islands. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus pannosa is a species of oak native to south-central China. An evergreen tree or shrub, it is found at very high elevations, flourishing at up to 4,270 metres above sea level. It is classified in subgenus Cerris, section Ilex.

<i>Quercus <span style="font-style:normal;">subg.</span> Quercus</i> Subgenus of Oak trees

Quercus subgenus Quercus is one of the two subgenera into which the genus Quercus was divided in a 2017 classification. It contains about 190 species divided among five sections. It may be called the New World clade or the high-latitude clade; most species are native to the Americas, the others being found in Eurasia and northernmost North Africa.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Denk, Thomas; Grimm, Guido W.; Manos, Paul S.; Deng, Min & Hipp, Andrew L. (2017), "An Updated Infrageneric Classification of the Oaks: Review of Previous Taxonomic Schemes and Synthesis of Evolutionary Patterns", in Gil-Pelegrín, Eustaquio; Peguero-Pina, José Javier & Sancho-Knapik, Domingo (eds.), Oaks Physiological Ecology. Exploring the Functional Diversity of Genus Quercus L, Tree Physiology, vol. 7, Cham.: Springer International Publishing, pp. 13–38, doi:10.1007/978-3-319-69099-5_2, ISBN   978-3-319-69099-5
  2. ↑ "Cyclobalanopsis Oerst.", International Plant Names Index (IPNI), Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens , retrieved 2023-02-24
  3. ↑ Denk, Thomas; Grimm, Guido W.; Manos, Paul S.; Deng, Min & Hipp, Andrew L. (2017-11-02), "Appendix 2.1: An updated infrageneric classification of the oaks" (xls), figshare, doi:10.6084/m9.figshare.5547622.v1 , retrieved 2023-02-17
  4. ↑ Halliday, James, Wine bottle closures, Halliday Wine Companion, retrieved 2023-02-24
  5. ↑ Simeone, Marco Cosimo; Cardoni, Simone; Piredda, Roberta; Imperatori, Francesca; Avishai, Michael; Grimm, Guido W.; Denk, Thomas (2018). "Comparative systematics and phylogeography of Quercus Section Cerris in western Eurasia: inferences from plastid and nuclear DNA variation". PeerJ. 6: e5793. doi: 10.7717/peerj.5793 . ISSN   2167-8359. PMC   6195796 . PMID   30356975.
  6. 1 2 Carrero, Christina; Jerome, Diana; Beckman, Emily; Byrne, Amy; Coombes, Allen J.; Deng, Min; González Rodríguez, Antonio; Sam, Hoang Van; Khoo, Eyen; Nguyen, Ngoc; Robiansyah, Iyan; Rodríguez Correa, Hernando; Sang, Julia; Song, Yi-Gang; Strijk, Joeri; Sugau, John; Sun, Weibang; Valencia-Ávalos, Susana & Westwood, Murphy (2020), The Red List of Oaks 2020 (PDF), Lisle, IL: The Morton Arboretum, retrieved 2023-02-24
  7. ↑ Huang, Chengjiu; Zhang, Yongtian & Bartholomew, Bruce, "Cyclobalanopsis", in Wu, Zhengyi; Raven, Peter H. & Hong, Deyuan (eds.), Flora of China (online), eFloras.org, retrieved 2023-02-24
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