Found these growing in my black compost bin. Tiny spore clusters on the outside start out looking like bumps. Can't find this anywhere. Snow white. Closest I found is a Hawaii mushroom which might have made it over on a watermelon. Any help identifying would be appreciated. Upended a couple to show the gills, attached and no frill on the stem. Had to darken the picture quite a bit, they are so white that the spores didn't show up well.
I’ve never seen that one, and we’ve had a variety of mushrooms here.
I stay away from all mushrooms not in the super market. I am too ignorant of their culture, etc. to do otherwise.