White Oak Bark (Immune) is native to England and has been naturalized in the U.S., where it is found mainly in the East. It grows as high as 100 feet and can live as long as 1,000 years. The trees are valued in the making of cabinets, tables and other furniture. Oak trees also bear acorns, which were a staple in the Native American diet. They were sometimes leached, dried and ground into flour. The Indians often gathered the acorns and stored them to ensure a continual winter food supply.

The key substances of white oak are tannin and quercin. Tannin is present in the bark at approximately 11 percent and accounts for white oak’s bitter and astringent qualities. White oak contains the minerals manganese, calcium and zinc.