grew on broken branche of birch

grew on a linden tree (Tilia)

On a branch of goat willow (Salix caprea).
1). Hymenophore
2). In the fracture - trama and tubes of the fruiting body

photo 3 - the same mushroom exactly 2 months later. (12/01/2020)
photo 4 - the fruiting body is eventually covered by algae (18/03/2020)

It grew on a pine branch that had fallen to the ground...