On partly buried eucalyptus wood
I think this might be Dryad's saddle. I've included a picture of the gills.
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.