Coprinus comatus

Coprinus comatus, commonly known as the shaggy ink cap, lawyer's wig, or shaggy mane, is a species of fungus. The young fruit bodies first appear as white cylinders emerging from the ground, then the bell-shaped caps open out. The white caps are covered with scales, the origin of its common names. The gills beneath the cap are white, then pink, then turn black. This mushroom is unusual because it will turn black and dissolve itself in a matter of hours after being picked or depositing spores. The mushroom is often seen growing about lawns, gravel roads, and waste areas in the Northern Hemisphere and more locally in the Southern Hemisphere. When young it is an excellent edible mushroom but it spoils quickly and resembles some poisonous species....read more on Wikipedia.