The interweb seems to think this is a specimen of Elm Oyster. But it would be unwise to identify mushrooms by the wisdom of the crowd.
The only known fact is that it was growing on an apparently healthy Box Elder tree, in a partially shaded grove in southeastern Michigan, in the autumn of 2018.
As a child I was taught that mushrooms with white gills are poisonous, while those with brown gills are safe to eat. That family wisdom led one day to my poor uncle falling violently ill, not long after I had showed him some mushrooms that were growing in the field behind our property. I didn’t like mushrooms, but he did, and I showed them to him, because they had brown gills.
He survived. I came out of it with the knowledge that rules of thumb can have important exceptions.
Even the inverse exception applies. Any grocery store can set you up with a pack of oyster mushrooms — and they have white gills. At least a few people on the Internet also seem to feel that the white-gilled Elm Oyster, which might be pictured above, is perfectly edible. But don’t take my word for it.
