I can help out a bit. It's a Lepiota or 'Parasol Mushroom'. Just underneath the gills will be a 'ring'. Likely either Chlorophyllum molybditges or 'Green Spored Lepiota'(most frequent cause of poisoning in U.S.), Macrolepiota procera or Macrolepiota rachodes. The later two have white spores, while the first has green spores which in age, turns the white gills greenish. Very photogenic, and won't harm you to handle it. Just don't eat 'em til you know which one it is for sure. All these occur throughout the U.S. (east & west).