White oak (Quercus alba) grows across the majority of the eastern United States. White oak was a vital species to shipbuilders in colonial times and the wood today still has great value in cabinets, barrels and interior work. The state tree of Illinois, the white oak is also a coveted landscaping species, with builders often saving them during construction so the homeowner may have a handsome shade tree. You can identify a white oak by its different elements.
Look at a white oak and estimate how tall it is. The average white oak will grow between 80 and 100 feet tall and have a trunk with a 3 to 4 foot diameter. In the open and growing uninhibited, the white oak will have spreading branches and a rounded crown. These trees may be shorter but will have a crown that is as wide if not wider as the white oak is high, according to the Ohio Department of Natural Resources.
Inspect the leaves of the white oak and look for characteristics such as their shape, length and color. Study them closely and you will see that the leaves on the same tree have different shapes, with the leaves usually possessing between seven and ten lobes. Remember that there can sometimes be more and sometimes be less of these lobes. Measure the leaves; they should be in the range of from 4 to 7 inches long. Look for blue-green color in the leaves before they change to a brown-red in the autumn.
Examine the acorns of the white oak, either when they are still in the tree or after they fall to the ground. Look for them to grow by themselves or in back-to-back pairs and have a bumpy cap that only manages to cover about a quarter of the fruit. Measure the acorns for length, looking to see if they are in the range of 3/4 inch to 1 inch long.
Study the bark of white oak and look for it to be a light grayish color that almost appears white in the right light. Feel the bark and you will notice it has a flaky texture and develops in plates that covers the trunk and branches.
Scan a white oak in the spring for its flowers. Remember that a white oak has both male and female flowers on it, with the male flowers the more conspicuous of the sexes. They droop down and are as long as 4 inches, with a yellow-green color, while the smaller female flowers that will bear the acorns are red-green.