Hoof Fungus
Latin: Fomes fomentarius
Svenska: Fnöskticka
Deutsch: Zunderschwamm
The wood softener
Hoof fungus is a common fungus on birch trees. It begins to break down the wood, softening it. Song thrushes can then peck through the wood and use it for a home. When hoof fungus is dried, it turns into a great isolating material!
Hoof fungus is common throughout Sweden.
Wikipedia article on hoof fungus