A toadstool is not a toad, and it is not a stool. It is a fungus.
And as Matt Groening informed us in his wonderful book School Is Hell (he knew: he went to the same school that I did),
A fish stick is not a fish, nor is it a stick. It is a fungus.
Now, in the spirit of the quizzes that once appeared on the Brunching Shuttlecocks (and those that now appear at Modesty Panel), we here present a list of twenty things that may or may not be fungi. Can you sort them out?