Coprinus comatus

Known as Shaggy Mane to most mushroom collectors, Coprinus comatus is common, easy to identify, good to eat but hard to preserve. It turns into black inky slime in a matter of a day or two. It can grow abundantly after warm rains in disturbed areas, by roadsides, in gravel and recently spread mulch. It has black spores and an elongated (nearly cylindrical) cap which forms an egg shape when immature, but melts from the bottom up with age. The cap has a distinctive hairy (shingled) white and brown exterior, giving it the shaggy name. I've seen them grow up to a foot tall, and I've also found them still buried under mulch, even in maturity. The shaggy mane is only good to eat when still young, before it begins to deliquesce into black ink. As it starts to get inky, the flavor turns sour and nasty; however, when young it has a tender texture and delicious subtle flavor.