Gyromitra poison info?

Andrew Grant adgrant at
Tue Jun 3 15:13:09 EST 1997

In article <33932B10.6F45 at>,
jp at wrote:

>Hi there...I'm interested in the rocket fuel toxin in the 
>Beefsteak mushroom. I've read that it's considered poisonous
>but that millions eat it. Very strange! Can someone enlighten
>me? ---I recall also reading that different regions have beefsteaks
>which have LESS of the toxin, making them edible. Is this the
>case with the commercial beefsteaks available in Scandanavia?
>I also read awhile back about a 'controlled substance' case about
>such a company exporting beefsteaks to the US and getting into
>trouble. Any news? Thanks...

   I have never heard the Gyromitra called a beefsteak mushroom.  That
name is usually applied (at least in the US to Boletus edulis.  Gyromitra
esculenta is often called the false morel and contains the poison
monomethyl hydrazine (MMA). MMA is a recognized poison.  People have eaten
these mushrooms safely after cooking because MMA is volatile, it boils at
87.5 C, and cooks off (at least to a large extent) during cooking.  There
have been cases where the cook became seriously ill by inhaling the vapor
from cooking while those that ate the mushrooms did not.  Note that MMA
has been confirmed in about 6 or 8 gyromitra species and reported or
suspected of being present in about a dozen other sorts of mushroom but so
far as I know not including any boletus species.   The "controlled
substance" case sounds more like a hallucinogenic mushroom.
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Andy Grant

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