List of Quercus species
The genus, as is the case with many large genera, is divided into subgenera and sections (see Taxonomic ranks in botany).
Species with evergreen foliage ("live oaks") are tagged #. Note that the change from the deciduous to the evergreen term (or vice versa) has happened on numerous occasions in the genus Quercus, and does not necessarily indicate that the species concerned are closely related.
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.
Western Asia and Western North America, produces catkins up to 10cm long, fruit matures annually.[3]
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).
Europe, Asia, north Africa. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless or slightly hairy.
