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) torpedo attack. By 19:15, "Royal Oak" gunners had observed the German battlecruiser squadron and opened fire at the leading vessel, . The gunners overestimated the range initially, but by 19:20 had found the correct distance scored a pair of hits aft, which did not inflict serious damage. "Derfflinger" then disappeared in the haze, so "Royal Oak" shifted fire to the next battlecruiser, . She scored a hit at 19:27 before "Seydlitz" too was lost in the mist. While "Royal Oak" was attacking the battlecruisers, a German torpedo boat flotilla launched an attack on the British line. "Royal Oak"s secondary guns