Quercus afares

Taxonomy

The relationship of Q. afares to other oaks was investigated in 2006. It was initially classified in Q. section Cerris, because of morphological similarities with two other species, Turkey oak (Quercus cerris) of southern Europe and chestnut-leaved oak (Quercus castaneifolia) of the Caucasus and northern Iran. A 2017 classification still places it in this section. A 2006 genetic analysis using both nuclear (allozymes) and chloroplastic markers found that Q. afares originated as a hybrid of Q. suber and Q. canariensis. Although it is common for oaks of related species to hybridize, the parent species of Q. afares are from genetically distant sections of the genus, Q. suber from section Cerris and Q. canariensis from section Mesobalanus. C. Mir et al. maintain that because Q. afares is genetically, morphologically and ecologically differentiated from its parental species, it should therefore be considered a stabilised hybrid species. Like Q. suber, it has a biennial reproductive cycle, corky bark, and similar fruit, and also does not occur on limestone soils. Unlike Q. suber, which is limited to coastal areas with mild winters, Q. afares shares the cold-tolerance of Q. canariensis which shares some of its mountain habitats.

References

References

1. Jerome, D., Carrero, C. & Gorener 2020. Quercus afares. The IUCN Red List of Threatened Species 2020: e.T78802767A85409923. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T78802767A85409923.en. Downloaded on 1 November 2020.
2. (2017). "Appendix 2.1: An updated infrageneric classification of the oaks".
3. (2006). "Endemic North African ''Quercus afares'' Pomel originates from hybridisation between two genetically very distant oak species (''Q. suber'' L. and ''Q. canariensis'' Willd.): evidence from nuclear and cytoplasmic markers". Heredity.