Be advised that FUNGI Magazine this month has published an article about a little-known species of Amanita that is spreading out across the country from its former range along the Texas Gulf Coast. This large and distinctive mushroom has recently been found far more widely across the Midwest and South, from Kansas to Illinois to Maryland, typically growing on lawns. There does not seem to be any report of it in Arizona yet.
Amanita thiersii normally has a characteristic shaggy appearance, but this flaky surface can be washed away in the rain, making it possible to mistake for young specimens of Agaricus or Lepiota.
This is a potentially deadly mushroom, worth knowing and avoiding when you are looking for white-colored edibles.