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 featurs, 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 tree or shrub in the genus Quercus of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta and the Casuarinaceae (she-oaks). The genus Quercus is native to the Northern Hemisphere and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America has the largest number of oak species, with approximately 160 species in Mexico, of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species.

<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 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 myrsinifolia</i> Species of oak tree

Quercus myrsinifolia is an Asian species of tree in the beech family Fagaceae. It has several common names, including bamboo-leaf oak, Chinese evergreen oak, and Chinese ring-cupped oak. Its Chinese name is 小叶青冈; pinyin: xiǎo yè qīng gāng, which means little leaf ring-cupped oak, in Japan it is called white oak and in Korea it is known as gasinamu (가시나무). It is native to east central and southeast China, Japan, Korea, Laos, northern Thailand, and Vietnam. It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus asymmetrica is an oak tree species in the beech family Fagaceae. It is found in China and northern Vietnam. It is placed in subgenus Cerris, section Cyclobalanopsis.

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.

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.

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

Quercus rex is an Asian species of tree in the family Fagaceae. It has been found in the seasonal tropical forests of northern Indochina, northeastern India, and also in the province of Yunnan in southwestern 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 northern Indochina and in southern China (Yunnan). It is placed in subgenus Cerris, section Cyclobalanopsis.

Quercus gomeziana is a tree species in the beech family Fagaceae. There are no known subspecies. It is placed in subgenus Cerris, section Cyclobalanopsis.

<i>Quercus <span style="font-style:normal;">×</span> turneri</i> Species of plant in the genus Quercus

Quercus × turneri, known as Turner's oak, is a hybrid species of white oak native to Spain. It is a naturally occurring hybrid of holm oak and pedunculate oak, found where their ranges overlap, but was first described from cultivation. A semi-evergreen tree of small to medium size with a rounded crown, it was originally raised at the Holloway Down Nursery of Spencer Turner, Leyton, Essex, UK, noted by the zoologist Jean-Baptiste Lamarck at Trianon, Versailles in 1783, as the chêne de turnère. An early specimen was planted at the Royal Botanic Gardens, Kew in 1798; it was uprooted in the Great Storm of 1987 but resettled in the ground and then increased its healthy growth. Its 'Pseudoturneri' cultivar has gained the Royal Horticultural Society's Award of Garden Merit.

Quercus yonganensis is a species of oak native to southeast China. It is placed in subgenus Cerris, section Cyclobalanopsis, the ring-cupped oaks.

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

Quercus floribunda, called the Moru oak or Mohru oak, Tilonj oak and green oak, is a species of oak native to Afghanistan, Pakistan, India's western Himalaya, and Nepal, typically found from 2,000 to 3,000 metres above sea level. It is in the subgenus Cerris, section Ilex. An evergreen tree with a dense crown reaching 30 m (98 ft), it is an important fuelwood and fodder species.

Quercus look, also known as the look oak and the Mount Hermon oak is a species of oak in subgenus Cerris, section Cerris, native to the Levant region of Western Asia, including northern Israel, Lebanon, and Syria. Of the local oak species, it prefers to grow at the highest altitudes, for instance at c. 1800 m on Mount Hermon.

<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.

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

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., Cham.: Springer International Publishing, pp. 13–38, 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, 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