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
HMS Royal Oak (08) who survived the sinking while serving as a Boy, First Class on "Royal Oak", served as the Royal Oak Association's Honorary Secretary. An annual ceremony of remembrance is held by the survivors and descendants of the crew at the Naval War Memorial, Southsea, on the anniversary of the sinking. The last remaining survivor of "Royal Oak", Arthur Smith, who had been a 17-year old Boy, First Class when the ship was struck, died on 11 December 2016. He had been on watch at the bridge and had jumped from the sinking ship, swimming in the wrong direction until he was