Identification help

[Virginiahunter]

Deer caps? Found these gems over an old Apple tree stump, popping up en masse out of the grass. Genus? Edible?

[Dave W]

Looks like a species of Coprinellus. The name C. micaceus is applied to a group of very similar species that usually show shiny grains on the cap. Commonly called Mica Caps. Although I don't see the "mica" flakes on the caps seen here, I think these fall into Mica Cap category. Often rainfall washes the flakes away. Mushroom Expert says that one possible way to distinguish the true C. micaceus from a very similar species C. truncorum is that micaceus has a pruinose stem surface (powdery) and truncorum has smooth stem surface. A hand lens is likely necessary to see this. I can't tell from the photos. Also, spore shape varies somewhat among the different species in the Mica Cap group.

[Virginiahunter]

Wow thanks. I keep reading that both types are genetically similar/identical. Is it safe to assume that even if they're truncorum that they're edible? I'm not asking for a legal answer, just general knowledge. I can't find much on the truncorum.

[Dave W]

I have little experience with eating these types. Many years ago I tried some C. micaceus and found them to be okay. Nothing special, but nothing bad.

One thing to consider is that some of the coprinoid species react adversely with alcohol. I've never heard of any such alcohol-related report regarding Coprinellus, but the tipping-point relevant to the adverse reaction may vary among individuals.

I would advise caution. Actually, when trying any type of mushroom for the first time, the usual precautions should be used... small amount, well-cooked, keep a sample in the fridge, avoid alcohol, refrain from eating other types of mushrooms.

Over the years, at least some truncorum collections have likely been labeled as micaceus.