Quercus alba
White Oak (Quercus alba)

Distribution Map to Right
Counties in blue contain tree

Shape and Distribution
The white oak is a large tree that grows to a height of 100 ft. The trunk is typically 2 to 4 feet in diameter. Grown trees in open areas have widely spreading, rigid, horizontal branches which form a broad, round-topped crown. 

White oak grows in moist as well as dry soils, but prefers rich, well-drained uplands, slopes, and terraces. Mature trees occur in full sun to shade, but young white oaks thrive only in full sun. They cannot tolerate shade and therefore do not regenerate in densely shaded forests. 

White oak is present in every county in Illinois. It is a common component of the eastern deciduous forest. Its range extends from Maine across Minnesota, south to eastern Texas, and east to northern Florida.

Interesting Facts
The white oak is the official Illinois state tree, and occurs in every county in Illinois, but it rarely occurs in pure stands.

White oak bark scales off in thin plates, leaving smooth patches in places. The scaling is caused by a harmless fungus (Aleurodiscus  oakesii), which affects the outer (non-living) bark of the tree.

The gypsy moth feeds on white oak as well as other oaks, and has caused the death of many white oaks over the last few decades.

Identifying Features
White oak bark is light gray with shallow ridges, and scales off leaving whitish-gray patches. 
The twigs are slender and smooth and the buds are reddish brown or gray, rounded, and 1/8 inch long.
The leaves of white oak are alternate and vary in size and shape. They are broader at the tip than at the base (toward the leafstalk) and are generally from 5 to 9 inches long and from 2 to 4 1/2 inches wide. They have 7 to 9 rounded lobes (not bristle-tipped as in pin oak, black oak, or northern red oak, for example). The lobes may be deeply incised or shallow. The leaves are smooth (hairless) and light green, with the underside paler than the upper surface. Leaves turn red in the autumn.
White oak flowers in the spring when the leaves start to appear. Both male and female flowers occur on the same tree. The female (pistillate) flowers are small, red, and without petals, and the male (staminate) flowers are in drooping yellow clusters. All oaks are wind pollinated.
Acorns are produced when the tree is about 20 years old. They are borne either singly or in twos and occasionally threes. They are oblong and approximately 1/4 inch long, with the "cup" covering the top third of the nut. The nut is shiny and light brown to greenish brown and the cap is light gray and slightly hairy. The number of acorns produced varies from year to year, with larger crops occurring during "mast years", every four to ten years. The acorns provide a valuable food source for many birds and mammals.

The coarse-grained, durable, heavy wood of white oak is used for everything from fine furniture, floors, cabinets, and barrels, to fence posts and fuel. Once considered the prime source of building material for these items, today white oak has been largely replaced by several species of eastern red oak, which grow faster and are easier to treat with preservatives.

Native Americans used white oak to treat a wide variety of ailments including diarrhea, mouth sores, chapped skin, asthma, and coughs. Derivatives from white oak trees were also used as antiseptics, emetics, and fever-reducing washes.