Tree ball

Tree ball

Observation - Tree ball - UK and Ireland. Description: I have no idea what this is. A fungus? A growth from the tree caused by disease or a parasite? The first three pictures are of the first one I found, the other two are from the same tree and I assume are the same thing.

I have no idea what this is.
A fungus? A growth from the tree caused by disease or a parasite?
The first three pictures are of the first one I found, the other two are from the same tree and I assume are the same thing.