Planted a bunch of them, and hooked up a power conduit to them. They're mature, but I'm not sure what to do. Do I need to harvest them and toss them in a generator?

EDIT: Okay, I see I planted Power Shrooms, not Powergen shrooms. It says, to create a Powergen shroom, I need 250 raw fungus, which I don't have. I don't have Ideology enabled, so I'm not sure where to source that. Power shrooms should probably drop raw fungus when harvested, because they seem to be useless otherwise.