the fruit body basidiocarp of fomitopsis betulina birch polypore, bracket or or razor strop on a birch trunk, top view

autumn background bark beautiful betulina betulinus birch body bracket brown closeup color cracked detail environment fall fomitopsis forest fruit fungi fungus gray macro medicinal medicine mushroom mycology natural nature outdoor outdoors phytochemistry piptoporus plant polypore razor razorstrop season skin strop surface toadstool traditional tree trunk white wild wood woodland