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From: john@basser.oz (John Mackin)
Newsgroups: sci.bio
Subject: Re: Mushroom identification query
Summary: Coprinus comatus
Message-ID: <1523@basser.oz>
Date: 9 Oct 88 14:45:13 GMT
References: <883@galaxy>
Organization: Dept of Comp Sci, Uni of Sydney, Australia
Lines: 66

In article <883@galaxy> rosenblum@jupiter.rutgers.edu writes:

> I saw an interesting-looking mushroom (actually, a few of them) on the
> New Brunswick campus of Rutgers a few days ago, and I was wondering if
> mycologists out there could tell me what it was (or may have been) based
> on the casual description that I can give.  It was about 15 cm high,
> with a smooth, almost translucent off-white stem.  The cap was curved
> downward over the stem (like the straw mushrooms used in Chinese
> cooking), with the distance from the top of the cap to its bottom edge
> being about 40% of the height of the mushroom.  What was particularly
> interesting was the surface of the cap.  The top surface had a rather
> striking even shingled pattern, which at a distance looked almost like
> a honeycomb, but on closer inspection proved to be just regularly placed
> scale-like things with their free edges towards the bottom of the cap;
> there were something like six to ten rows of these, with the shingles
> in one row between the shingles of the row above (like seats in a well-
> designed movie theater).  The bottom of the cap was even more striking:
> it was jet black and shiny, and looked like nothing so much as fresh tar,
> to some extent obscuring the gills.  Any ideas on what that might have
> been?

Absolutely.  The last comment places the mushroom (without question,
as far as I am aware; if you get replies to the contrary I would be
most interested in seeing them) in the genus Coprinus.  They are
the only agaricales that are dark-spored and have gills that
are autolytic (self-digesting).  Had you seen the mushroom earlier
in its life, the gills would have been initially light in color, gradually
darkening to black before autolysis commenced.

It is hard to be certain from the description, but I would say that
your mushroom is very likely to be Coprinus comatus.  This fungus
is said by some to be the best-tasting of all mushrooms.  It's not
my personal favorite, but I do consider it very good eating indeed.
It is not at all pleasant once it has started to autolyse; you must
eat it while its flesh is still solid.

This mushroom, like many members of the genus Coprinus, contains
the compound disulfram, which is marketed under the trade name
Antabuse.  It is sometimes administered to alcoholics to discourage
them from consuming alcohol.  A very unpleasant reaction will
ensue if one takes alcohol while using disulfram, beginning with
hot flushes and progressing to dizziness, headache, palpitations,
dyspnoea, nausea and vomiting, lasting up to several hours.
    [What is happening physiologically is this: primarily in the
    liver, alcohol in the presence of nicotinamide adenine
    dinucleotide is reduced to acetaldehyde by the enzyme
    alcohol dehydrogenase.  This reaction is relatively slow,
    and is the step that limits the rate at which alcohol is
    removed from the body.  The acetaldehyde is then converted
    to acetate in a reaction catalyzed by the enzyme aldehyde
    dehydrogenase.  Normally, this reaction proceeds very rapidly,
    and no acetaldehyde accumulates.  The action of this enzyme
    is inhibited by disulfram, and it is the resulting accumulation
    of acetaldehyde that is responsible for the adverse effects.]
So, make certain that you do NOT consume alcohol with, or
within several hours after the consumption of, mushrooms of
the genus Coprinus.

I would strongly suggest that you have any mushroom you intend
to eat identified by a knowledgeable person on the spot.

John Mackin, Basser Department of Computer Science,
	     University of Sydney, Sydney, Australia

john@basser.oz.AU (john%basser.oz.AU@UUNET.UU.NET)
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