Oak apple due to the superficial resemblance and the preponderance of the oak marble gall in the wild. Other galls found on oak trees include the oak artichoke gall and the acorn cup gall, but each of these has its own distinctive form. Some common oak-apple-forming species are the "Biorhiza pallida" gall wasp in Europe, "Amphibolips confluenta" in eastern North America, and "Atrusca bella" in western North America. Oak apples may be brownish, yellowish, greenish, pinkish, or reddish. Oak galls have been used in the production of ink since at least the time of the Roman Empire. From the Middle Ages to
Royal Oak and three royal crowns, differentiated by colour. The site of the tree is adjacent to Boscobel House, but is not owned by English Heritage as the house is. The surrounding land is owned and farmed by Francis Yates Partners, who allow the public access along a path from the garden of the house. The tree standing on the site today is not the original Royal Oak, which is recorded to have been destroyed during the seventeenth and eighteenth centuries by tourists who cut off branches and chunks as souvenirs. The present day tree is believed to be a two or