Oak

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 divided into two subgenera, or sections:

• Leucobalanus, the white oaks
• Erythrobalanus, the red oaks

The white oaks are further subdivided into the chestnut oaks and the rest of the white oaks, while the red oaks are further subdivided into the live oaks and the rest of the red oaks.

Oaks are found all over the world; many species are evergreen. A hardwood[?], oak is used commonly in furniture and flooring. The bark of the 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.

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 (aka 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.

oak tree in summer

Some species of oak found in North America include:

• Quercus agrifolia - Coast live oak[?]
• Quercus alba - White oak
• Quercus arizonica - Arizona white oak[?]
• Quercus bicolor - Swamp white oak
• Quercus chrysolepis - Canyon live oak[?]
• Quercus coccinea - Scarlet oak[?]
• Quercus douglasii - Blue oak[?]
• Quercus ellipsoidalis - Northern pin oak[?]
• Quercus emoryi - Emory oak[?]
• Quercus falcata - Spanish oak[?], aka southern red oak
• Quercus gambelii - Gambel oak[?]
• Quercus garryana - Oregon white oak[?]
• Quercus grisea - Gray oak[?]
• Quercus havardii - Sand shinnery oak[?]
• Quercus incana - Bluejack oak[?]
• Quercus kelloggii - California black oak
• Quercus laevis - Turkey oak[?]
• Quercus laurifolia - Laurel oak[?]
• Quercus lobata - Valley oak[?]
• Quercus lyrata - Overcup oak[?]
• Quercus macrocarpa - Bur oak[?]
• Quercus marilandica - Blackjack oak
• Quercus michauxii - Swamp chestnut oak[?]
• Quercus muehlenbergii - Chinkapin oak
• Quercus nigra - Water oak[?]
• Quercus oblongifolia - Mexican blue oak[?]
• Quercus palustris - Pin oak
• Quercus phellos - Willow oak[?]
• Quercus prinus - Chestnut oak
• Quercus pungens - Sandpaper oak[?]
• Quercus rubra - Northern red oak
• Quercus shumardii - Shumard oak[?]
• Quercus stellata - Post oak[?]
• Quercus turbinella - Shrub live oak[?]
• Quercus velutina - Black oak
• Quercus virginiana - Live oak[?]
• Quercus wislizenii - Interior live oak[?]

Old World species of oak include:

• Quercus robur - English oak, pedunculate oak or truffle oak.

above; bark of English oak (Quercus robur)

above; timber of English oak (Quercus robur)

See also; Trees of Britain, Trees of the world