The Heathland Conservation Crew employed at Core Hill, Sidmouth, Devon…
All is not what it seems out there in nature, I’d assumed that an oak apple was a deformed acorn.
Oak Galls which are otherwise known as Oak Apples are intriguing growths that I’d never really considered until very recently. I’d naturally assumed that oak apples were slightly different forms of acorns but not so, they are the result of a species of wasp using oak buds as rearing chambers for their offspring.
Incidentally, oak galls have been used in the production of ink since at least Roman times by combining gallotannic acid from the galls of oaks and other trees with iron sulfate. Once dried it is non-water soluble and could only be erased by scraping a thin layer off the vellum writing surface.