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
Oak Apple Day some parts of the country as a "shick-shack") or sprigs of oak leaves, in reference to the occasion after the Battle of Worcester in September 1651, when Charles II escaped the Roundhead army by hiding in an oak tree near Boscobel House. Anyone who failed to wear a sprig of oak risked being pelted with bird's eggs or thrashed with nettles. In Sussex, those not wearing oak were liable to be pinched, giving rise to the unofficial name of "Pinch- Day"; similarly it was known as "Bumping Day" in Essex. In Upton Grey, Hampshire, after the church bells had been