Oak

From Wikinfo

Oak

File:Acrons.jpg
Acorns of Quercus kerrii (a species in
Quercus subgenus Cyclobalanopsis)

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fagales
Family:	Fagaceae
Genus:	Quercus

Species

List of Quercus species

The term oak can be used as part of the common name of any of several hundred species of tree in the genus Quercus. The genus is native to the northern hemisphere, and includes deciduous and evergreen species extending from cold latitudes to tropical Asia. The fruits of oaks are called acorns. The 'live oaks' - oaks with evergreen leaves - are not a distinct group, instead with their members scattered among the sections below.

Classification

The genus is divided into two subgenera and a number of sections:

Subgenus Quercus. Typical oaks. Widespread; acorns not tightly clustered, with scales on acorn cup arranged in spirals.

Section Quercus (synonym Lepidobalanus), the white oaks of Europe, Asia and North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless.
Section Mesobalanus, the Hungarian oak and its relatives of Europe and Asia. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. Quercus and sometimes included in it).
Section Cerris, the Turkey oak and its relatives of Europe and Asia. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless.
Section Protobalanus, the Canyon live oak and its relatives, in southwest USA & northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly.
Section Lobatae (synonym Erythrobalanus), the red oaks of North & Central America. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly.

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, above right), often treated as a separate genus Cyclobalanopsis.

List of Quercus species

Uses

Oaks are hardwood trees, the wood commonly used in furniture and flooring. The bark of Quercus suber, or Cork oak, is used to produce wine stoppers (corks). This species grows in the Mediterranean Sea region, with Portugal, Spain, Algeria and Morocco producing most of the world's supply. Some European and American oak species are used to make barrels where wine and other spirits are aged; the barrels contribute to the taste.

Of the North American oaks, the most prized of the red oak group for lumber, all of which is marketed as red oak regardless of the species of origin, is that of the northern red oak, Quercus rubra (a.k.a. Quercus borealis). The standard for the lumber of the white oak group, all of which is marketed as white oak, is the white oak, Quercus alba. White oak is often used for the construction of barrels for aging wine.

File:Oaktree.jpg
oak tree in summer

File:Oak tree.jpg

Large Oak Tree