Gyromitra poison info?

Jim Pirko jpirko at
Thu Jun 5 14:38:08 EST 1997

adgrant at (Andrew Grant) writes: > 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.
> -- 
> My email address in the header is altered to avoid junk mail.  If you wish to contact me by email substitute "water" for "nospam"
> Andy Grant

Gyromitra esculenta is called 'beefsteak' in Northern Michigan. As always 
much confusion about edibility. Half the people say yes, half say no. I 
don't mess around with it. 

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