Unknown Oyster-like mushroom

Unknown Oyster-like mushroom

Observation - Unknown Oyster-like mushroom - UK and Ireland. Description: I spotted this mushroom, which I thought was an oyster mushorrm growing from a dead tree stump. But it has no gills! It is totally smooth underneath. Others had grown to the size of a small plate, and the colour on top had faded to a lighter brown. I

I spotted this mushroom, which I thought was an oyster mushorrm growing from a dead tree stump. But it has no gills! It is totally smooth underneath. Others had grown to the size of a small plate, and the colour on top had faded to a lighter brown. I cannot identify it from any books.