The world's best-known fungus is sirely the Fly Agaric, Amanita muscaria. Garden gnomes sit on them, Walt Disney turns them into a troop of dancing Chinamen, children play with plastic ones. The wonderfully coloured fungus forms the motif of countless greetings cards and story-book illustrations and it is recognisable instantly to everyone as the poisonous toadstool, even to those who have never set eyes on a real one.