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List of Quercus species

From Wikipedia, the free encyclopedia

The genus Quercus contains about 500 known species, plus about 180 hybrids between them.[1] The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus Quercus was divided into the two subgenera Cyclobalanopsis, the ring-cupped oaks, and Quercus, which included all the other sections. However, a comprehensive revision in 2017 identified different relationships.[2] Now the genus is commonly divided into a subgenus Quercus and a subgenus Cerris, with Cyclobalanopsis included in the latter. The sections of subgenus Quercus are mostly native to the New World, with the notable exception of the white oaks of sect. Quercus and the endemic Quercus pontica. In contrast, the sections of the subgenus Cerris are exclusively native to the Old World.[2]

Unless otherwise indicated, the lists which follow contain all the species accepted by Plants of the World Online as of February 2023, plus selected hybrids that are also accepted,[1] with placement into sections based on a list produced by Denk et al. for their 2017 classification of the genus.[3]


Species with evergreen foliage ("live oaks") are tagged '#'. Species in the genus have been recategorized between deciduous and evergreen on numerous occasions, although this does not necessarily mean that species in the two groups are closely related.

Subgenus Quercus[edit]

Section Quercus[edit]

Section Mesobalanus was included in section Quercus in the 2017 classification used here. Other synonyms include Q. sect. Albae and Q. sect. Macrocarpae. The section comprises the white oaks from Europe, Asia, north Africa, Central and North America.[2] Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless.[citation needed]

Quercus hiholensis acorn in matrix

Section Ponticae[edit]

Species are native to Western Asia and Western North America. They produce catkins up to 10cm long; the acorns mature annually.[2]

Section Protobalanus[edit]

The intermediate oaks. Southwest USA and northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly.[citation needed]

Section Lobatae[edit]

The red oaks (synonym sect. Erythrobalanus), native to North, Central and South America.[2] Styles long, acorns mature in 18 months (in most species),[6] very bitter, inside of acorn shell woolly.[citation needed]

Section Virentes[edit]

Section Virentes has also been treated at lower ranks. Species are native south-eastern Northern America, Mexico, the West Indies (Cuba), and Central America.[2] A 2017 classification included seven species:[3]

Subgenus Cerris[edit]

Section Cerris[edit]

Species are native to Europe, north Africa and Asia.[2] Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless or slightly hairy.[citation needed]

Section Ilex[edit]

Species in section Ilex are native to Eurasia and northern Africa.[2] Styles medium-long; acorns mature in 12–24 months, appearing hairy on the inside. Evergreen leaves, with bristle-like extensions on the teeth. (Sister group to sect. Cerris and sometimes included in it.)[citation needed]

Section Cyclobalanopsis[edit]

Illustration of Quercus lamellosa, showing acorns in clusters, with visible rings on their cups

The ring-cupped oaks (synonym genus Cyclobalanopsis), native to eastern and southeastern tropical Asia. They have corns with distinctive cups bearing concrescent rings of scales.[2] They commonly also have densely clustered acorns, though this does not apply to all of the species.[citation needed] About 90 species.[2]


Section uncertain[edit]

Intersectional hybrids[edit]


  1. ^ a b "Quercus L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2023-02-17.
  2. ^ a b c d e f g h i j 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. doi:10.1007/978-3-319-69099-5_2. ISBN 978-3-319-69099-5.
  3. ^ a b 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. ^ Borgardt, S. J.; Pigg, K. B. (1999). "Anatomical and developmental study of petrified Quercus (Fagaceae) fruits from the Middle Miocene, Yakima Canyon, Washington, USA". American Journal of Botany. 86 (3): 307–325. doi:10.2307/2656753. JSTOR 2656753. PMID 10077494.
  5. ^ 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.
  6. ^ Kershner, Bruce, and Craig Tufts. National Wildlife Federation Field Guide to Trees of North America. New York: Sterling Pub., 2008. Print.
  7. ^ a b Backs, J.R. & Ashley, M.V. (2021). "Quercus Conservation Genetics and Genomics: Past, Present, and Future". Forests. 12 (7): 882. doi:10.3390/f12070882.

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