On living sugar maple
I would naively guess Dryad's Saddle, but am not sure
Growing on elm tree
Polyporus is a genus of fungi in the Polyporaceae family. It is a genus used for the production of single cell proteins, sources of mixed protein extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria (grown on agricultural wastes) used as a substitute for protein-rich foods, in human and animal feeds.