Subgenus Quercus. Typical oaks. Widespread; acorns not tightly clustered, with scales on acorn cup arranged in spirals.
Section Quercus (synonym Lepidobalanus). The white oaks. Europe, Asia, north Africa, North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless.
Section Mesobalanus. Europe, Asia, north Africa. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. Quercus and sometimes included in it).
Quercus dentata - Daimyo oak - eastern Asia
Quercus frainetto - Hungarian oak - Europe
Quercus macranthera - Caucasian oak - western Asia
Quercus variabilis - Chinese cork oak - eastern Asia
Section Protobalanus. Southwest USA & northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly.
Quercus chrysolepis - Canyon live oak # - western North America
Quercus palmeri - Palmer oak # - western North America
Quercus tomentella - Channel island oak # - western North America
Quercus vacciniifolia - Huckleberry oak # - western North America
Section Lobatae (synonym Erythrobalanus). The red oaks. North, Central & South America. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly.
Quercus agrifolia - California live oak # - western North America
Quercus canbyi - Canby oak # - Mexico
Quercus coccinea - Scarlet oak - eastern North America
Quercus ellipsoidalis - Northern pin oak - eastern North America
Quercus falcata - Spanish oak, aka southern red oak - eastern North America
Quercus humboldtii - South American Oak # - northern South America
Quercus hypoleucoides - Silverleaf oak # - western North America
Quercus imbricaria - Shingle oak - eastern North America
Quercus incana - Bluejack oak - western North America
Quercus shumardii - Shumard oak - eastern North America
Quercus velutina - Black oak - eastern North America
Quercus wislizenii - Interior live oak # - western North America
Subgenus Cyclobalanopsis. Cluster-acorn oaks. A large group of evergreen oaks in east Asia with clustered acorns and the scales on the acorn cups in distinct concrescent rings (see photo, top right on the Quercus main page); often treated as a separate genus Cyclobalanopsis.
Section Cyclobalanopsis.
Quercus acuta - Japanese evergreen oak # - eastern Asia
Quercus glauca - Glaucous-leaf oak # - southeastern Asia
Quercus kerrii - Kerr's oak # - southeastern Asia
Quercus myrsinifolia - Bamboo-leaf oak # - eastern Asia
Species with evergreen foliage are tagged #. Note that evergreen character has evolved on numerous occasions in Quercus, and does not necessarily indicate that the species concerned are closely related.
