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
Prix Royal-Oak in 1964. The present system of race grading was introduced in 1971, and the Prix Royal-Oak was classed at the highest level, Group 1. For a period it was held in mid-September. It was switched to late October in 1977. The Prix Royal-Oak was opened to horses aged four or older in 1979. It was opened to geldings in 1986. Most successful horse (2 wins): Leading jockey (6 wins): Leading trainer (7 wins): Leading owner (6 wins): Prix Royal-Oak The Prix Royal-Oak is a Group 1 flat horse race in France open to thoroughbreds aged three years or older. It