Wrinkled Crust

 A couple of years back I decided to leave standing a 12cm diameter Sorbus that died in the garden, mainly as I thought it would be of benefit for invertebrates. Today I noticed that there were eruptions all over the trunk and branches of Phlebia radiata (Wrinkled Crust Fungus), a wood-decomposing mushroom with a strangely wrinkled spore-bearing surface.