bjrogg you are right.
On the pics that could be a trametes versicolor (or an other trametes). In Germany it is called "Butterfly trametes".
This fungus is inedible. A powder of the dried fungus is used in the traditional chinese medicine.
Of the mushrooms growing on or with trees, I particularly like oyster mushrooms (Pleurotus ostreatus), chicken of the woods (Laetiporus sulphureus) or ruffle hen (Sparassis crispa).
