This polypore, when you come across it, may be one of two distinct species. But, because they are so similar, it’s not possible to tell them apart without DNA analysis. Trametes elegans is native to the US, and Trametes gibbosa is native to Europe. But, this European relative has now spread into the US. So, unless you have a DNA lab at hand, you’ll have to be satisfied knowing that you found one or the other. When I first saw this mushroom, I was not certain that it was Trametes elegans/gibbosa. Trametes pubescens is typically smaller and thinner than this was. Trametes gibbosa is a little chunkier and bumpier, with a less uniformly flat top. But, the green algae on the cap is common on T. gibbosa. So, when I saw this polypore that was kind of in-between in size, and in-between in thickness, I wasn’t exactly sure what it might have been. But, when I peered underneath I saw elongated pores. Which, along with the other features listed above made it a dead giveaway for Trametes elegans/gibbosa. Especially since most other Trametes species have small round pores. This was just a young specimen who did not have a chance to develop the typical lumpy/bumpy cap surface.
