The present NYMS was reincarnated some 40 years ago by the composer John Cage and a small group of other mushroom lovers and students. Mushrooms are the fruiting bodies of fungi, of which the vegetative growth is typically underground or in wood.
Fungi serve a major recycling role in nature, breaking down dead trees and other organic material.
Fungi also help nourish trees and other plants, thus playing a key role in the health of our forests. And yes, some fungi can also play a destructive role in nature by attacking living things such as trees. Most mushrooms are not poisonous and quite a few are very good edibles. Unfortunately there are no simple foolproof rules to distinguish the edible from the poisonous. One must learn individual mushroom species if one plans on eating mushrooms.