Found in Scotland (UK) under a Scots pine. Coastal. Approx 45-50mm (2" ish). I didn't pick it to get underside shots as there was only this only visible. Looked through my books and I can't find one similar.
Found in the Willamette Valley, OR. I poked it and it is a softer texture. Kinda looks muddy, but not. I think the tree it is on the roots of might be an oak?