Identify Oak - The Major Oak Species of North America

The term oak can be used as part of the common name of any of about 400 species of oak trees and shrubs in the genus Quercus (from Latin "oak tree). The genus quercus is native to the northern hemisphere, and includes deciduous and evergreen species extending from cold latitudes to tropical Asia and the Americas. Oaks have spirally arranged leaves, with a lobed margin in many species; some have serrated leaves or entire leaves with a smooth margin. The flowers are catkins, produced in spring. The fruit is a nut called an acorn, borne in a cup-like structure known as a cupule; each acorn contains one seed (rarely two or three) and takes 6–18 months to mature, depending on species. The "live oaks" (oaks with evergreen leaves) are not a distinct group, instead with their members scattered among the sections below.

The Common North American Oak Species

• black oak
• bur oak
• cherrybark oak
• laurel oak
• live oak
• Oregon white oak
• overcup oak
• post oak
• pin oak
• northern red oak
• scarlet oak
• Shumard oak
• southern red oak
• swamp chestnut oak
• water oak
• white oak

• willow oak

Dormant Oak Identification:
Has 5-sided pith; has variable bark so not very helpful; has clustered buds at tip of twig; has persistent leaves on live and water oak; has slightly raised, semi-circular leaf scars; has numerous bundle scars; has acorns persistent on twigs or dropped under the tree.
Leaves: alternate, variable in shape, short stalked.
Bark: gray and scaly or blackish and furrowed.
Twigs: slender with star-shaped pith.
Fruit: acorns.

ash | beech | basswood | birch | black cherry | black walnut/butternut | cottonwood | elm | hackberry | hickory | holly | locust | magnolia | maple | oak | poplar | red alder | royal paulownia | sassafras | sweetgum | sycamore | tupelo | willow | yellow-poplar

ID Glossary