I live in the Northwest suburbs of Illinois and we moved into this house last year. I noticed these mushrooms popping up in one corner of my yard and I’ve never seen this type before. They don’t seem to grow a typical stalk and cap shape and stay rather low to the ground. I’ve had to dig down under them a decent amount to get them out of the ground. We’re approaching Fall now so colder nights and hot humid days.
I might have figured it out. It looks to be a ganoderma sessile type fungi which is often associated with declining trees. It just so happens that this area of my yard is right next to a tree that isn’t doing too well from poor drainage. There were times where if I dug deep enough I’d end up hitting a tree root, so that tracks well.