State Symbol: Illinois State Tree White Oak (Quercus alba)
Approximately twenty native species of oak occur in Illinois. From 1908 to 1973, the state tree was designated as “Native Oak.” White oaks prefer rich, well-drained soil. In Illinois they are found in a variety of habitats, but they grow best on uplands, slopes, and terraces. The geographic range of white oak extends from Maine to Minnesota, south to eastern Texas and northern Florida.
White oak can be very large. Individual trees commonly reach a height of 100 feet (30 m). When growing in the open, they often have widely spreading branches, making them excellent shade trees.
The leaves of the white oak are quite variable in size and shape. They generally are between five and nine inches long (13-23 cm). they are narrow toward the stem and have seven to nine lobes. The leaves turn red or purple in the Fall.
White oaks begin to produce acorns when they are about twenty years old. The acorns are about an inch long (2.5cm). Acorns are produced in the Fall, and the number varies from year to year. Large numbers of acorns are produced every four to ten years. When acorns fall to the ground, they are an important food for many kinds of birds and other animals.
The wood of the white oak is strong, durable, and beautiful. For these reasons the wood is harvested for use in cabinetry, interior finishing, and general construction. The bark is pale gray and narrowly furrowed. It has scaly ridges and smooth patches that are a result of a fungus that invades the outer, non-living portion of the bark.
In 1907, Mrs. James C. Fessler of Rochelle suggested to state officials that Illinois schoolchildren vote for a State Tree and State Flower. They selected the Oak as State Tree. The votes were: Oak, 21,897; Maple, 16,517; Elm, 5,082. Senator Andrew J. Jackson of Rockford introduced a bill making it official in 1908. In 1973, a special poll of some 900,000 children changed the Official State Tree from “Native” Oak to White Oak and the amended bill was signed into law that year. Number of Votes: White Oak 333,964 Northern Red Oak 142,247.
Learn more about oak trees in Illinois Forests.
A.C. Koelling, 1976, "The White Oak: state tree of Illinois," The Living Museum, 38:358-360.
R.H. Mohlenbrock, 1990, Forest Trees of Illinois, sixth edition, Springfield, IL: Illinois Department of Conservation, 331pp.