Protobalanus

The genus ''Quercus'' contains about 500 species, some of which are listed here. 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. Now the genus is commonly divided into a subgenus ''Quercus'' and a sugenus ''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.

Legend

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''

Section ''Quercus''

up'' Quercus hiholensis'' acorn in matrix
The white oaks (synonym sect. ''Lepidobalanus'' or ''Leucobalanus''). Europe, Asia, north Africa, North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless.
* '' Quercus ajoensis'' — Ajo Mountain shrub oak, Blue shrub oak — Arizona, New Mexico, Baja California
* '' Quercus alba'' — white oak — eastern and central North America
* ''Quercus aliena'' — Oriental white oak — eastern Asia
* ''Quercus ariifolia'' — Mexico
* ''Quercus arizonica'' — Arizona white oak — # southwestern U.S., northwestern Mexico
* '' Quercus austrina'' — bluff oak — southeastern North America
* ''Quercus × bebbiana'' — Bebb's oak — northeastern North America
* ''Quercus berberidifolia'' — California shrub oak — # California
* ''Quercus bicolor'' — swamp white oak — eastern and midwestern North America
* ''Quercus × bimundorum'' — two worlds oak
* ''Quercus boyntonii'' — Boynton's post oak — south central North America
* ''Quercus brandegeei'' — Brandegee oak- Baja California Sur
* ''Quercus carmenensis'' — Carmen oak — Coahuila and Texas
* ''Quercus chapmanii'' — Chapman oak — # southeastern North America
* ''Quercus chihuahuensis'' — Chihuahua oak — northern Mexico and Texas
* ''Quercus cornelius-mulleri'' — Muller oak — # southwestern North America
* '' Quercus conzattii'' — Mexico
* '' Quercus copeyensis'' — # Costa Rica, Panama
* '' Quercus dalechampii'' — southeastern Europe
* '' Quercus depressipes'' — Davis Mountain oak — northern Mexico and Texas
* '' Quercus deserticola'' — # Mexico
* '' Quercus diversifolia'' — Mexico
* ''Quercus douglasii'' — blue oak — California
* ''Quercus dumosa'' — coastal shrub oak — # southern California, Baja California, Arizona
* '' Quercus durata'' — Leather oak — # California
* '' Quercus edwardsiae'' — Mexico
* ''Quercus engelmannii'' — Engelmann oak — # southern California, Baja California
* '' Quercus fabrei'' — Faber's oak — central to southern China
* ''Quercus faginea'' — Portuguese oak — # southwestern Europe
* '' Quercus fulva'' — Mexico
* †'' Quercus furuhjelmi'' — Eocene to Miocene - Alaska, Kazhakstan
* ''Quercus fusiformis'' — Texas live oak or plateau live oak — # south central North America
* ''Quercus gambelii'' — Gambel oak — southwestern North America
* ''Quercus garryana'' — Oregon white oak or Garry oak — western North America
* ''Quercus geminata'' — sand live oak — # southeastern United States
* '' Quercus glaucoides'' — # Mexico
* '' Quercus greggii'' — # Mexico
* '' Quercus griffithii'' — southeast Asia
* ''Quercus grisea'' — gray oak — # southwestern North America
* '' Quercus hartwissiana'' — Strandzha oak — southeastern Bulgaria, northern Turkey, western Georgia, southwestern Russia
* '' Quercus havardii'' — Havard oak, shinnery oak, shin oak — south central North America
* †'' Quercus hiholensis'' — Miocene — # Washington State
* ''Quercus hinckleyi'' — Hinckley oak — # Texas, northwestern Mexico
* '' Quercus hondurensis'' — Honduras oak — # Honduras
* ''Quercus iberica —'' Georgian oak — Caucasus an bordering regions
* '' Quercus infectoria'' — Aleppo oak, Cyprus oak — southern Europe, southwestern Asia
** '' Quercus infectoria'' Olivier var. ''veneris'' (C.K. Schneider) Meikle, or ''Quercus boissieri'' Reut./Boissier oak — Mount Hermon, Golan Heights, and Jordan
* '' Quercus insignis'' — Mexico, Belize, Costa Rica, Guatemala, Panama
* '' Quercus intricata'' — Coahuila scrub oak — # two isolated localities in west Texas, northern Mexico
* '' Quercus john-tuckeri'' — Tucker's oak — California
* ''Quercus laceyi'' — lacey oak — Edwards Plateau of Texas, northern Mexico
* ''Quercus laeta'' — Mexico
* '' Quercus lanata'' — woolly-leaved oak — # Himalayas, southeast Asia
* '' Quercus lancifolia'' — southwestern North America, Mexico, South America
* '' Quercus leucotrichophora'' — Banj oak, blackjack oak, grey oak — # Himalayas
* '' Quercus liebmannii'' — Mexico
* ''Quercus lobata'' — valley oak or California white oak — California
* ''Quercus lusitanica'' — gall oak or Lusitanian oak — Iberia, North Africa
* ''Quercus lyrata'' — overcup oak — eastern North America
* ''Quercus macrocarpa'' — bur oak — eastern and central North America
* '' Quercus margarettae'' — sand post oak — southeastern North America
* ''Quercus magnoliifolia'' — Mexico
* '' Quercus martinezii'' — # Mexico
* '' Quercus mohriana'' — Mohr oak — # southwestern North America
* ''Quercus montana'' — chestnut oak — eastern North America (= ''Quercus prinus'')
* ''Quercus michauxii'' — swamp chestnut oak — eastern North America
* '' Quercus microphylla'' — Mexico
* '' Quercus minima'' — dwarf live oak — # southeastern North America
* ''Quercus mongolica'' — Mongolian oak — eastern Asia
* ''Quercus muehlenbergii'' — Chinkapin oak — eastern, central, and southwestern US (West Texas and New Mexico), northern Mexico
* ''Quercus oblongifolia'' — Arizona blue oak, Southwestern blue oak, or Mexican blue oak — # southwestern U.S., northwestern Mexico
* ''Quercus obtusata