oak appleEnglishOxford New American Dictionaryoak apple /ōk ˈapəl, oʊk ˈæpəl/ ▸ noun a spongy spherical gall which forms on oak trees in response to the developing larvae of a gall wasp. The wasp is Biorhiza pallida (in Europe) or Amphibolips confluenta (in America), family Cynipidae.
EnglishOxford New American DictionaryEnglishOxford New American Dictionary
EnglishOxford New American Dictionary