I went looking for mushrooms in art. There are plenty.
ABOVE: Fragment of a Greek funerary stele, c. 470-460 BCE, possibly Persephone and her mother Demeter
holding mushrooms
Its meaning is unknown, but I like it: Wikiepeida article on this stele, image at the Louvre Museum, who say they're holding possibly poppies, pomegranates, or sacks of grain? They sure look more like mushrooms to me.
