White oak is a large deciduous tree in the beech family that is native to eastern North America. While its wood is used to make fine furniture, most notably mission style furniture. The wood is also used in shipbuilding and home construction and to make leak-proof barrels in which to age whiskey and wine.
The bark, however, has a long history of use by Native Americans. Various phenolic compounds and tannins present in the bark also lend the herb astringent qualities. Powdered white oak bark is usually encapsulated as a dietary supplement, but it can also be infused in oil for use in topical ointments and salves.