Birch Polypore

Piptoporus betulinus, commonly known as the birch polypore, birch bracket, or razor strop fungus,grows mostly on birch and is very common.

The razor strop refers to the fact that the cut surface was used to get a fine finish on a blade.

I spotted this one today as I drove past and managed to keep my camera dry while I took the picture!

You can see a whole one here in a picture I took some time ago.