There are nearly 600 species of oak in the world and 80 of these grow in the United States. The tree is native to every region in North America. All the species can be divided into three types of oak tree: white, red and golden, which are Western species. The types of oak trees found in Kentucky include the northern red oak, the white oak and the scarlet oak.
Northern Red Oak
The northern red oak, also known simply as the red oak, is found throughout the Eastern United States. It is often planted as a street tree in cities and as an ornamental tree in parks. The tree ranges in height from 60 to 90 feet with a diameter of 2 to 3 feet. The bark is light gray and smooth with cracks running vertically down the trunk. Older trees have rougher patches of black bark. The leaves are symmetrical and 4 to 9 inches long with seven to 11 lobes. During the growing season the leaves are dark green and dull; in the fall they turn red, orange and brown. The acorns are pale brown and ripen in the fall.
The white oak is also called the Eastern white oak. The tree is one of the most important North American timber oaks because of its commercial value, according to "Field Guide to Trees of North America" by the National Wildlife Federation. The tree is widely planted in tree farms and its timber is used in a great deal of construction. The tree ranges in height from 60 to 80 feet and is 2 to 3 feet in diameter. The bark is cracked and scaly gray and white in color with a light gray underbark. The leaves are dull green, 5 to 9 inches in length with seven to nine rounded lobes. In the fall, the leaves turn light pink, red and purple. The acorns are light brown and ripen in the fall.
The scarlet oak is found in the Eastern United States and is known for its vivid foliage and long-lasting leaves in the fall. The tree ranges in height from 60 to 80 feet and is 1 to 2-and-1/2 feet in diameter. The bark is gray and smooth when young with intermittent rough ridges when older. The leaves are dark green and glossy, 3 to 7 inches in length, with seven deeply divided lobes nearly to the middle vein. Each lobe is tipped with a sharp bristle. The acorns are encased in a scaly cup and ripen in the fall.