Amanita phalloides
The World's Most Dangerous Mushroom
Written and produced by David. W. Fischer
Photographs of Amanita phalloides by Fred Stevens
W E B P A G E I N D E X
Introduction
"The Southeast Asian Problem"
Causes of Serious Mushroom Poisonings
Second Photo
Description of the Death Cap
Ecology and Range of A. phalloides in
North America
Equally Toxic North American Mushrooms
The Destroying Angel
Toxicology and Treatment
Overreaction...?
The Truth
NO MUSHROOM is worthier of fear than the terribly poisonous
Death Cap (Amanita phalloides). This single, widespread species
of mushroom is solely responsible for the majority of fatal and
otherwise serious mushroom poisoning cases, worldwide as well as in
North America. Indeed, one might argue that the Death Cap's notorious,
relatively frequent victimization of Homo sapiens is far
and away the best explanation (or rationalization) for the widespread
fear of edible wild mushrooms. This is the EXACT reason that the
infamous Amanita muscaria mushroom, which is an edible mushroom in
countless cultures, has been labeled as a poison by the FDA. It
was in the same family as the deadliest mushroom known to man, but it
is not the poisonous variety.
If there was a berry this bad...
This mushroom is rare in most parts of North America but locally
common in such areas as the San Francisco Bay area, where it is
typically found from mid-autumn through late winter. Primarily a
European species, there is no evidence that the Death Cap is native to
North America. Ecologically, it is a beneficial mycorrhizal
fungus---it lives on the roots of live trees, providing phosphorus,
magnesium, and other nutrients to the tree in exchange for
carbohydrates.
In California, it occurs under live oak and cork trees (it
apparently was brought in with cork tree seedlings, and has since
adapted to native oaks). There is a similar situation in the
Irondequoit area north of Rochester, New York: the Death Cap was first
discovered in Durand-Eastman Park in the 1970s under Norway spruce
trees that had been imported as nursery stock decades earlier. It has
since been found in increasing numbers and in an ever-enlarging but
still local range, under native oaks; it is rather reliably found
there from late September through late October.
The Death Cap has also been reported under oaks in southern Oregon.
There are other mushrooms which are as poisonous---or nearly as
poisonous---as A. phalloides, but this one species causes far
more poisonings than the others. There is an explanation for this.
Most victims of life-threatening mushroom poisoning in North
America are people from Southeast Asia---Laos, Cambodia, Thailand,
Viet Nam. They apparently mistake Death Caps for edible "Paddy-Straw"
(Volvariella volvacea) mushrooms. The two are similar in
several ways---cap color, size, and the white "cup" around the base of
the stalk---but different in others (for example, the Paddy-Straw has
a pink spore print, the Death Cap a white spore print; and the Death
Cap has a partial veil). The Paddy Straw mushroom occurs in tropical
and temperate areas worldwide, and is especially common in Southeast
Asia; the Death Cap, alas, does not occur in Southeast Asia, so folks
from that part of the world are unaware of the lethal "look-alike."
Consider the following---a revealing comment from USENET:
bionet.mycology (June 1997):
"My wife comes from Thailand. Last Fall, we were strolling
through our woods when she spied a mushroom. She was overjoyed to
find that America, too, has straw mushrooms, and assured me it was
edible. Knowing even less about mushrooms than I do now, but knowing
the danger of not knowing, I advised her to leave it alone. ...the
specimen did indeed resemble a straw mushroom, except for the
presence of a ring on the stipe [stalk]."
--Tim Childress
In North America, Death Cap poisonings have been reported from
California, Oregon, and New York. In New York, the only known victims
to date were natives of Laos. In California and in Oregon, most
reported Death Cap poisonings have also involved Southeast Asian
immigrants.
The poisoning cases typically involve several victims---often
including children---who "enjoyed" the mushrooms as a group. One or
two deaths per case are common. The treatment of choice is often liver
transplantation. Especially with early diagnosis, other effective
treatments include massive doses of penicillin, which stimulates the
liver's defenses.
The Death Cap should be sought in every part of North America
where Norway spruce or cork trees have been cultivated. If found, its
presence should be publicized locally, regionally, and nationally to
reduce the risk of further tragedies. It is especially vital to
educate communities of Southeast Asian immigrants about this lethal
mushroom.
The "but I thought it was edible..." phenomenon, where the
victims either thought they "knew" the mushroom species or applied
some folk myth such as "no poisonous mushrooms grow on wood,"
is one of four causes of mushroom poisoning in humans.
Another often-tragic cause is similar---an individual eating a
dangerously toxic wild mushroom in the belief (or with the hope) that
it is a hallucinogenic species.
The most common cause of mushroom exposures, by far, is
infant and toddler "grazing"---where young children ingest mushrooms
as a way of experiencing their environment. (This phenomenon is also
commom with domestic dogs!) Sadly, in many areas, physicians
automatically opt for traumatic treatment via Epicac, even in cases in
which the patient shows no symptoms and uneaten specimens are
available for examination, without consulting a mycologist to attempt
to determine the identity and toxicity of the mushroom.
Incredibly enough, the fourth cause of mushroom poisoning is simple
foolishness: a false presumption that most mushrooms are safe, and/or
that poisonous mushrooms "look," "taste," or "smell" bad. (As many
victims of Death Cap poisoning can attest, that is not true!)
The Death Cap can be easily diagnosed as such.
The cap is 2¼--6" (6--16 cm) wide, smooth, with greenish
to yellowish pigments, usually sticky or slippery but sometimes dry,
often adorned with one to several patches of thin white veil
tissue. The gills are white, crowded together, and very
finely attached to the upper stalk. In young specimens, a white,
membranous partial veil tissue extends from the edge of the
cap to the upper stalk, covering the gills (later remaining attached
to and draping from the upper stalk). The stalk is white to
pallid, up to 6" (15 cm) long or tall, with a large rounded bulb at
the base; the bulb includes a white sac-like volva (see the two
photos on this webpage). THE BASE OF THE STALK AND THE TELL-TALE
VOLVA ARE OFTEN BURIED IN THE SOIL.
Amatoxins contained in the Death Cap are responsible for the
symptoms suffered by its victims. They are present in all the tissues
of the mushroom, in sufficient concentration that two or three grams
are considered a potentially lethal dose. Several other species in
genus Amanita---most notably the all-white "Destroying Angels"
(A. virosa, A. bisporigera, and A. verna)---contain
comparable levels of amatoxins. Moreover, several species of other
genera of gilled mushrooms (notably Conocybe filaris, Galerina
autumnalis and G. venenata, and Lepiota josserandii
and L. helveola) also contain these toxins.
Conocybe filaris is a dainty, fragile species unlikely to be
considered as food, but it may pose a "grazing" danger to small
children and to dogs.
Galerina venenata is a small, uncommon brown mushroom
sometimes found on lawns in the Pacific Northwest; it is unlikely to
be considered as potential food, but it poses a "grazing" danger to
small children and to dogs. Galerina autumnalis is a small
brown mushroom that grows on dead/decaying wood; mushroom enthusiasts
must be diligent to avoid inadvertently picking specimens of this
species while harvesting more robust edbile mushrooms that grow on
wood.
Genus Lepiota includes several worthwhile edible species of
much larger stature than the diminutive species shown to contain
amatoxins; mushroom enthusiasts must be diligent to avoid small
Lepiotas, as at least one fatality has resulted from this genus in
North America. (Note: a close relative of the Lepiotas---Chlorophyllum
molybdites, the "Green-spored Lepiota"---contains unrelated toxins
that cause severe gastrointestinal symptoms; while ingestion of this
species is not generally life-threatening, it can cause dehydration
severe enough to require hospitalization for fluid and electrolyte
maintenance.)
The Destroying Angels---Amanita virosa
and other closely related white Amanitas---have been consumed by
ignorant collectors, both as food and, in at least one case, under the
mistaken notion that they might be hallucinogenic.
Visually, the Destroying Angel is very similar to its more
notorious brother; the most notable difference is the lack of green or
yellow pigments (though some slight yellowing may be observed on some
specimens). Like the Death Cap, the Destroying Angel is a very easily
identified mushroom.
The cap of the Destroying Angel is 2¼--6" (6--16 cm) wide,
smooth, dry to slightly sticky. The gills are crowded together and
may appear either very finely attached to the upper stalk or
unattached. In young specimens, a white, membranous partial veil
tissue extends from the edge of the cap to the upper stalk, covering
the gills (later remaining attached to and draping from the upper
stalk, but it is very thin and fragile, hence is sometimes not seen
on mature specimens). The stalk is white to pallid, up to 8" (21 cm)
long or tall, with a small, rounded bulb at the base; the bulb is
enclosed by a sac-like volva. All parts of the Destroying Angel are
white. THE BASE OF THE STALK AND THE TELL-TALE VOLVA ARE OFTEN
BURIED IN THE SOIL.
The Destroying Angels are common and widespread throughout much
of North America; the danger of these easily-identified species---and
their identifying traits---ought to be widely taught in elementary
school and beyond.
"Amatoxins are cyclopeptides composed of a ring of amino acids
that inhibit the production of specific proteins within liver and
kidney cells. Without these proteins, cells cease to function.
Following ingestion...five to twenty-four hours (average, twelve
hours) pass before nausea, vomiting, abdominal pain, and diarrhea
begin. These initial symptoms are followed by a brief period of
apparent improvement, but without treatment, severe liver damage and
kidney failure often result in coma and death."
--Edible Wild
Mushrooms of North America by Fischer and Bessette (1992,
Univ. of Texas Press, Austin)
The delay before onset of symptoms, coupled with the intitial
symptoms' mimicry of influenza and other gastrointestinal viruses and
the marked (albeit temporary) improvement of most patients beginning
two or three days after ingestion, pose inherent problems in prompt
diagnosis and treatment.
In cases where early diagnosis is accomplished, effective therapies
have included massive doses of penicillin and other compounds which
pharmacologically inhibit the amatoxins from effecting their most
severe liver damage. In more severe cases, especially those in which
diagnosis is delayed further by failure to suspect amatoxin poisoning,
liver transplant is the preferred therapy.
For most patients, full recovery to their states of health prior to
hospitalization is unlikely.
Death Cap Poisonings Elicit Overreactive Statements
In California, in January, 1997, some folks picked some wild
mushrooms, cooked and ate them, without knowing what they were
doing... without consulting a good mushroom field guide... without
carefully comparing specimens to descriptions and photos... in short,
without properly identifying the mushrooms they picked.
Once again, the mushrooms they picked were "Death Caps" (Amanita
phalloides).
Once again, folks ended up with serious liver damage; several of
them died.
And, once again, some authorities spouted overreactive nonsense,
not merely implying but explicitly stating that it is
inherently dangerous for anyone but an "expert" to pick and eat wild
mushrooms.
The Associated Press reported (1/8/97):
An outbreak of wild mushroom poisonings has sickened at least
nine people in Northern California, with three victims in intensive
care Wednesday facing possible liver transplants.
The most seriously ill were felled by the "death cap'' mushroom,
known technically as Amanita phalloides, which can destroy the
liver. One victim was Sam Sebastiani Jr., 31, a member of the
Sebastiani wine family.
The Mushroom Council, which represents commercial mushroom
producers and importers throughout the United States, said this in a
news release:
The Mushroom Council urges the public to be extremely cautious
when foraging for wild mushrooms outside, especially in fields and
forests, because of potential health dangers that can be caused by
some wild varieties [sic]... The untrained and uneducated
person can make an innocent mistake when hunting wild mushrooms that
could result in illness or even death... Commercially produced
mushrooms that are in your supermarket or in prepared foods are
carefully cultivated agricultural products, grown year around.
This was, perhaps, neither terribly unreasonable, nor terribly
overreactive. It certainly was opportunistic for the Mushroom Council
to steer consumers toward their industry's produce---and away from the
free foods of the forests and fields---in the capitalist tradition. No
one can blame them for that. Indeed, it can be argued that some folks
would hear the news stories and react with a fear of all
mushrooms, including the safe cultivated species, so the Mushroom
Council was merely trying to mitigate against the danger of public
misperception.
Editorial note: Never mind that some of the most widespread
cases of serious poisoning by mushrooms in North America has been
the result of botulism caused by errors in the canning of
commercially cultivated mushrooms... and be sure to take a good look
at those "fresh" mushrooms in the produce department of your
favorite grocery store, for this "short-shelflife" commodity often
shows serious signs of decay at the supermarket.
The problem here is that "untrained and uneducated" can be
misinterpreted as "lacking formal training and education in
mycology"... and that is simply not true.
Rose Ann Soloway, administrator of the American Association of
Poison Control Centers, had this to say (and The Mushroom Council
plugged it into their news release):
It is our strong recommendation that people not pick and eat
wild mushrooms unless they, in fact, are experts, or the person
identifying the mushrooms is someone with whom they would trust
their life.
Hmmm... "expert"? What, exactly, is an expert?
Better question: how much of an "expert" should one be to identify
wild mushrooms for human consumption?
Millions of North Americans pick and eat wild mushrooms every year,
without as much as a belly ache.
Are they "experts"? Yes! At least, they are experts on the
edible wild mushrooms they know. Either their parents or
grandparents taught them how to identify morels, or puffballs, or
meadow mushrooms, or they have a good field guide and they read
it... or both.
No one with a reasonable understanding of the importance of
properly identifying mushrooms---with a serious awareness that some
species are fatally toxic---falls victim to the Death Cap. The folks
who eat Death Caps do not use field guides: they just pick the damned
things and eat them. No trip to the library. No reading. No spore
prints. No idea what a "partial veil" is or what "gill attachment"
means.
So... Is it really dangerous to eat wild mushrooms?
How dangerous is it to drive a car? If you're drunk or careless, it
is VERY dangerous; if you're sensible and pay attention, it is
reasonably safe.
Consider this: Would you pick and eat an unfamiliar berry simply
because it "looked good"? Of course not. Finding,
identifying, preparing, and eating wild mushrooms can be a delightful
pasttime---IF it is done intelligently.
Otherwise, it is a terrible "accident" waiting to happen.
Copyright ©1997 by David W. Fischer. All rights reserved.
This site maintained by David W. Fischer, whose e-mail address is
basidium@aol.com
.
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