Phellinus igniarius

Mushrooms and other fungi are certainly difficult to identify and learn about. I have recently noticed hard, brown, almost woody mushrooms on aspen trees, and have (almost) determined that they are Phellinus igniarius, which may be known as willow bracket or tinder fungus or possibly false tinder polypore.  Or perhaps flecked-flesh polypore.  Not to mention false tinder conk and hardwood trunk rot.  There might also be about twenty other scientific names that could pertain to this organism!  It's enough to make me stop noticing fungus.

One website tried to get me to identify these fungi by comparing their 'profile' to either a dolphin or a catfish or possibly an unnamed Star Wars creature.  What?  I suppose either my imagination is failing me or I have the completely wrong species.   Or the website is mocking my efforts.

The U.S. Forest Service has a photo that quite matches mine, though, so I guess I'll go with false tinder polypore.  I mean, if you can't trust the government...

There seems to be no Internet consensus over whether these fungi are terribly harmful to their host trees or not.  They do seem to be parasitic, but it may be nothing.  Or it may rot the tree.  Some people seem to suggest that you can in some fashion or another use them to start a campfire.  Just make sure you have the right species.  I guess.

Then I saw a massively big one which I though could possible be the same thing, only on a larger scale.  I give up.