Last winter a cluster of lovely polypores exploded out of the corner of an RV I'm staying in. It's been getting beat on by our 66" of rain for years. I couldn't figure where it had come from.
As you surely know, OSB (oriented strand board) is one of the gickest and cheapest (so, ubiquitous) lumber products. It's widely deployed in RVs. I was gutting part of this RV and found, among other astonishing decays, the OSB flooring shot through with mycelia. I realized that the polypore cluster had fruited from mycelia colonizing one-fifth of the trailer, at least, and that it was eating something so toxic it can't be burnt or put near waterways. And rural folk love to save on dump runs! (Sadly, for many that means "throw it in the back 40".)
What is this thing? I have no plans to eat it or use it for medicine lol, but I wonder if the culture should be encouraged somewhere on the property for remediation purposes. I piled the myceliated gutted OSB in a shady non-food area and wonder how long before it is gone.
Here is more info on Peziza domiciliana.
http://identification.growing-mushrooms.com/mushroom/peziza-domiciliana-1181/ Best to go through all the steps for keying it out.
Most pezizas really look like a cup fungus, and this one doesn't. In some of the pictures, this fungus looks more like a cup fungus. In others, it doesn't. I won't decide for you, but I will give you information to help you decide.