The C. molybidites has a dull green spore print. It could quite posibly be that growing on the lawn. But a spore print is essential for ID If its white then it most likely a Lepiota of some sort. C. Molybideites is toxic although no fatalities have ever been attributed to it.It normally causes gastric up sets. Some can eat it with impunity after a special way of cooking. Not ME. by the way cool pics your getting way better. Just in case quick class in making a spore print because i know your new to this biz. Cut the cap off and lay it on a piece of paper. (for this specimen I recommend black paper) leave it over night and you will see the spore print in 6 to 24 hours. It is a good way to Id mushrooms. Some times in the wild if several are bunched together you can see the color of the spore print on some of the other mushrooms growing next to each other. OK keep taking pics