Mushrooms... what are they?

So Doug, we are having a debate at my work about whether mushrooms are considered a vegetable in terms of food. The debate gets even more complex because apparently the scientific community considers a mushroom actually closer to the animal kingdom while the FDA considers it a vegetable. So which is it?

A: The honest answer is "maybe".

The term "vegetable" is similar to "germ", in that it is in general use but does not have a precise definition. "Vegetable" generally refers to the edible parts of a plant, but commonly includes mushrooms and other edible fungi, and no one seems to get torn out of the frame about it. Certainly mushrooms themselves haven't weighed in on the issue, and, as far as I know, they have no lobbyists on either side. It might be entertaining to make a good case that mushrooms are really animals, then see the reactions of the vegetarians at PETA.