List of Quercus species

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^[update], 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]