Large round ball attached to Birch (1 Viewer)

[Dave Pearson]

Hi,

Can anyone throw any light on what this is? It appeared to be a large round ball attached to the top of a dead Silver Birch. Seen in the New Forest yesterday.

Thanks,

Dave.

 

[Butty]

Seems to be growing out of the tree, so not a wasps' nest. Dunno. The fungus next to it is Polyporus betulinus - or whatever it's called these days.

 

[Mono]

My guess is some sort of Crown Gall.