Brown roll rim

Paxillus involutus

Many people are scared of poisonous fungi such as death caps, or destroying angels, or deadly web caps, which kill you quickly, painfully, and reliably. Fungal poisoning though can be more subtle than that. Meet the brown roll rim, the fungus that could kill you after you'd eaten it one hundred times with no ill effects. That one last time, it causes an autoimmune reaction in its victims that destroys red blood cells, ultimately causing kidney failure. It is not a cumulative poison, as some sources suggest. The exact reasons why some, but not all, instances of brown roll rim consumption result in serious illness, are not known.

Because deaths by brown roll rims are so rare, the toxicity of this mushroom has not been recognised until recently. Indeed, in parts of Central and Eastern Europe it is still consumed, sometimes in great quantities, as evidenced by the photo below.

Looks great, but these are not for me

I have to admit that this species highlights a serious issue with wild food generally: in truth, you never can have a total guarantee that the stuff you bring in from the forest is safe. There are no biological, chemical or radiological controls to reassure you, unlike in big supermarkets (although, the recent horsemeat burger scandal shows that even their procedures are not 100% reliable).

Fortunately, with properly identified edible mushrooms the risk is minimal. But brown roll rims? No matter how inviting that pot of cooked mushrooms looks, I'm giving it a miss.

Image credits:
Paxillus involutus
Cooked brown roll rim (personal communication)