I call this my vampire mushroom. There is a certain area, in my garden, where mushrooms just seem to spring up overnight.
If you go out early in the morning you'll find a number of delicate little ones standing up quite perky, in the shade of a small evergreen but, as soon as the sun rays creep above the level of the bush,and hit the mushrooms, they begin to collapse and shrivel up and, by late afternoon, it's almost impossible to find even a trace of them amongst the mulch.