The birch polypore (Piptoporus betulinus) is a remarkable fungus because it looks so much like its host plant, the silver birch (Betula pendula). Whether this is a real attempt at camouflage or whether it inherits certain substances from the tree that makes it look that way I have no idea! Anywhere in the county, indeed country, where there are silver birch trees you will find some with this polypore fungus, it is very common. The fungus is named 'betulinus' as it is only ever found on birch trees; 'Betulina'. It is parasitic and will eventually destroy its host but it is believed that it only attacks dying trees and thereby hastens the natural recycling process. Silver birch is a short lived tree in any event.
The fruiting bodies of the fungus, as seen in the photograph, are visible all year although spores are only released in the autumn. They are certainly not edible although they are not poisonous but have a bitter taste that makes them very unpalatable. The velvet-like surface of the bracket was traditionally used for sharpening razors hence its other common name of the razor-strop fungus.