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Don’t Pick Poison! When Gathering Mushrooms for Food in Michigan Extension Bulletin E-2777 (Replaces E-1080) January 2002 MICHIGAN STATE UNIVERSITY EXTENSION MSU is an affirmative-action, equal-opportunity institution. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, marital status or family status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Margaret Bethel, Extension director, Michigan State University, E. Lansing, MI 48824. This information is for educational purposes only. Neither the authors nor Michigan State University assumes responsibility for the safety or well-being of any collector. Major revision of E-1080, 1/02-5M-KMF/LAW, $3, for sale only © 2002, Michigan State University Extension MICHIGAN STATE UNIVERSITY EXTENSION

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Don’t PickPoison!

When Gathering Mushrooms for Food in Michigan

Extension Bulletin E-2777 (Replaces E-1080)January 2002

MICHIGAN STATEU N I V E R S I T Y

EXTENSION

MSU is an affirmative-action,equal-opportunity institution.Michigan State UniversityExtension programs andmaterials are open to all without

regard to race, color, national origin, gender, religion, age,disability, political beliefs, sexual orientation, marital status orfamily status. Issued in furtherance of MSU Extension work,acts of May 8 and June 30, 1914, in cooperation with the U.S.Department of Agriculture, Margaret Bethel, Extensiondirector, Michigan State University, E. Lansing, MI 48824. Thisinformation is for educational purposes only. Neither theauthors nor Michigan State University assumes responsibilityfor the safety or well-being of any collector.

Major revision of E-1080, 1/02-5M-KMF/LAW, $3, for sale only

© 2002, Michigan State University Extension

MICHIGAN STATEU N I V E R S I T Y

EXTENSION

Don’tPick Poison!

When Gathering Mushrooms for Food in Michigan

Heather Hallenand

Gerard AdamsMichigan State University

Department of Plant Biology

Amanita bisporigera

Acknowledgement

The original bulletin, E-1080,Don’t Pick Poison, was written byIngrid C. Bartelli, former districtconsumer marketing agent for

Michigan State UniversityExtension, Marquette, Mich.

Front Cover: Amanita

Back Cover: Amanita muscaria

1

Introduction

At least 50 of the larger species of wildmushrooms that grow in Michigan areknown to be poisonous. There may be more.

The ultimate decision whether to eat awild mushroom is yours. Michigan StateUniversity, the Michigan Department ofPublic Health, the authors of thispublication and those contributing to thesubject matter assume no responsibility forthe safety or well-being of any mushroomcollector.

What is a poisonousmushroom?

For the purposes of this bulletin, we definea poisonous mushroom as one that may beexpected to have an adverse effect on asizable percentage of the population themajority of the time. This definitionexcludes idiosyncratic reactions andallergies that may cause a person to havean adverse reaction to a usually ediblemushroom. Just as some people areallergic to wheat or peanut butter, somepeople are allergic to certain mushrooms.

Approximately 2,500 species of large,fleshy wild mushrooms grow in Michigan.By “large and fleshy” we mean those fungibig enough to be seen and large enough tomake a meal when collected in quantity.

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . 1

What is a poisonous mushroom? . . . . . . . . . . . . . . . . . . . . . . . . 1

Poisonous wild mushrooms grow in Michigan . . . . . . . . . . . . . . . . . . . 2

Some mushroom myths . . . . . . . . . . . . . 4

Why are mushrooms poisonous? . . . . . 5

Why are people poisoned? . . . . . . . . . . . 6

What can you do to protect yourself?. . . . . . . . . . . . . . . . . . . . 7

Mushroom biology/mushroom anatomy. . . . . . . . . . . . . . . . 10

White Amanita mushroomsare poisonous at all stages . . . . . . . . . . 10

Mushroom toxins . . . . . . . . . . . . . . . . . . 14

Amatoxins . . . . . . . . . . . . . . . . . . . . . 15

Cortinarius toxins . . . . . . . . . . . . . . . . 20

Monomethylhydrazine. . . . . . . . . . . 22

Coprine . . . . . . . . . . . . . . . . . . . . . . . . 24

Psilocybin, psilocin . . . . . . . . . . . . . . 27

Muscimol, ibotenic acid . . . . . . . . . . 29

Muscarine . . . . . . . . . . . . . . . . . . . . . . 32

Unknown toxins . . . . . . . . . . . . . . . . 34

Should you collect wild mushrooms?. . . . . . . . . . . . . . . . . . 40

Report poisonings . . . . . . . . . . . . . . . . . 41

Human poisoning centers. . . . . . . . . . . 42

Additional resources . . . . . . . . . . . . . . . 43

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The number would be increased byseveral thousand if microscopic fungi wereincluded in the count. Within ourapproximately 2,500 large species, at least50 species are known to be poisonous.Anywhere from 60 to 100 species areregarded as generally safe for eating.

How can you tell them apart? You cannotdetermine whether a mushroom ispoisonous or safe by any easy, magicmethod. You must learn to positivelyidentify each individual mushroom youpick for food.

Poisonous wild mushroomsgrow in Michigan

From documented case histories and fromthe scientific literature, we have compileda partial list of Michigan mushroomsknown to be poisonous. Some are deadly;others, discomforting. Species that havecaused rare deaths under specialcircumstances are marked with anasterisk; those that are frequently deadlyare marked with two asterisks.Hallucinogenic species are marked with †.

Mushrooms that are predominantlypoisonousAgaricus praeclarosquamosusAmanita bisporigera**Amanita cothurnataAmanita muscaria*†

Amanita pantherina*Amanita phalloides**Amanita spretaAmanita tenuifolia**Amanita velatipesAmanita verna**

Amanita virosa**Boletus luridusBoletus satanusBoletus subvelutipesChlorophyllum molybditesClitocybe clavipes (with alcohol)Clitocybe dealbataClitocybe morbiferaConocybe filarisConocybe lacteaCoprinus atramentarius (with alcohol)Coprinus insignisGenus Cortinarius** (Cortinarius contains

more than 1,000 species. Most have notbeen tested or are of unknown edibility;some, such as C. orellanus, are deadlypoisonous.)

Genus EntolomaGenus Galerina**Gomphus floccosusGymnopilus spectabilis†

Genus Gyromitra** (Gyromitra esculenta, G. brunnea)

Hebeloma crustuliniformeHebeloma sinapizansHypholoma (Naematoloma) fasciculareGenus InocybeLactarius pallidusLactarius scrobiculatusLactarius torminosusLepiota subincarnata**Omphalotus illudensPanaeolus subalteatusPaxillus involutus*Pholiota squarrosoidesPsathyrella foetidissima†

Psilocybe caerulipes†

Psilocybe (Stropharia) cubensis†

Ramaria apiculataRamaria formosaRussula emetica

(continued on next page) (continued on next page)

Mushrooms that are predominantly poisonous (cont.)

4 5

Sarcosphaera crassaScleroderma citrinumTricholoma pardinumTricholoma saponaceumTricholoma subacutumTricholoma vaccinumTricholoma venenata

Edible mushrooms that occasionallycause gastric distress

Armillaria melleaLaetiporus sulfureusLepiota naucinaVerpa bohemica

In addition, most edible mushrooms cancause gastrointestinal distress if eaten raw.Armillaria mellea, the stumper or honeymushroom; Lepista nuda, the blewit; andMorchella species, the morels, areparticularly egregious in this regard.

Some mushroom myths

1. “If an animal eats it, I can eat it.” This isnot true. Squirrels and rabbits can safelyeat the Amanita mushrooms, which aredeadly poisonous to people.

2. “If I eat a little bit, wait for a while, anddo not get sick, the mushroom is safe.”The most dangerous mushroom toxinsknown have a delayed action.Amatoxins (deadly toxins in severalmushrooms) cause painful symptomsonly after 6 to 14 hours, but the onset ofsymptoms can be delayed for 36 hoursor more. Symptoms of poisoning byCortinarius toxins may take from 10 daysto three weeks to occur.

3. “Cooking the mushroom will destroythe toxin.” There is no way to destroymost of the dangerous mushroomtoxins. Cooking is recommended for allmushrooms because it will break downsome of the mushroom sugars that wecannot digest. A few fungal toxins aredestroyed by cooking, but the majorityof toxins are not.

4. “Tests” to distinguish poisonousmushrooms from wholesome ones arenot to be trusted. Folk tradition hasgiven rise to a number of tests: apoisonous mushroom is supposed todarken a silver coin; cookingmushrooms with silver is supposed toeliminate the poison; a mushroom issupposed to be safe if you can peel thecap; mushrooms growing on wood aresupposed to be safe. These areinvariably false. THE ONLY RELIABLEWAY TO DISTINGUISH A POISONOUSMUSHROOM FROM AN EDIBLE ONEIS TO LEARN TO IDENTIFY THEINDIVIDUAL SPECIES.

Why are mushroomspoisonous?

Sometimes the poison appears to serve adefensive role. Certain species of Russulaand Lactarius are extremely peppery andwill burn your mouth if you taste them.The burning, acrid taste effectivelyprevents people and animals from eatingthe mushroom, allowing it to mature andrelease its spores.

In other fungi, the purpose (if any) of thepoison is not so clear-cut. The deadlyAmanita species, unfortunately, are

Mushrooms that are predominantly poisonous (cont.)

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reported to be good-tasting. This trait, incombination with the characteristic delaybefore any symptoms appear, wouldimply that the toxin is not a very gooddefensive compound – at least not againsthumans. The toxins may have evolved todiscourage insect larvae.

Some toxins may serve some other,unidentified role in the fungus, and thephysiological effect that the chemical hason us may be mere coincidence. And sometoxins may have no role and may simplybe waste products. The mushroom is themost disposable part of the fungalorganism.

Why are people poisoned?

Many cases of poisoning occur inimmigrants who are not familiar with thelocal mushroom flora. A person may havesafely collected a familiar mushroom inhis/her native land and then moved to aplace where very similar-looking butpoisonous mushrooms occur.

Children are particularly susceptible tomushroom poisoning, for a variety ofreasons. Toddlers go through a “grazing”phase, in which anything the child canreach is put into its mouth. Slightly olderchildren may not realize that there’s adifference between the mushrooms theyeat on their pizza and the mushrooms thatgrow in the yard. Because children aresmaller than adults and are stilldeveloping, the dose required to make achild ill is often smaller than that requiredfor an adult. Symptoms of poisoning maydiffer and are often more severe inchildren.

Mushroom poisoning often occurs in thoseattempting to get high on “magicmushrooms”. This poisoning is usuallydue to mistaken identity, which results inhighly toxic species being inadvertentlycollected. Most hallucinogenic species arelittle brown mushrooms and, as such, looka great deal like other little brownmushrooms, some of which can be deadly.Since the 1960s, there have been numeroussevere poisonings of people whoconsumed Galerina species that theymistook for Psilocybe species.

Hunting and gathering wild mushroomsfor food can be an immensely rewardingexperience. You can enjoy pleasantexcursions in the woods and experiencethe satisfaction of collecting wonderfullyflavorful mushrooms for food. But youMUST take the time to learn about themushrooms you collect before you riskyour health or life for the sake of a meal.

What can you do to protectyourself?

Mushroom poisoning is eminentlyavoidable. The only way you can bepoisoned by a mushroom is by eating apoisonous mushroom.

1. Never eat any mushroom unless youknow what it is. You presumably wouldnot pick wild raspberries unless youcould tell a raspberry from deadlynightshade; by the same token, youshould not collect mushrooms for foodunless you can distinguish the foodspecies from the poisonous species.

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a) Use a reliable field guide that waswritten for your region of the country.Read the descriptions of themushrooms carefully; do not just relyon the pictures. Colored pictures areaids to identification, nothing more.Many mushrooms are extremelyvariable. Most books can spare onlyone or two pictures per mushroomand cannot demonstrate the full rangeof appearances.

b) Participate in a class on mushroomidentification. Both Michigan StateUniversity and the University ofMichigan offer such classes in the fall;additionally, special workshops maybe available. MSU Extension andMichigan Technical University havebeen offering a weekend-longworkshop on edible and poisonousmushrooms of Michigan the pastseveral years in September.

c) Go on mushroom hunts withknowledgeable persons. The classesand workshops mentioned abovehave a mushroom-huntingcomponent. The Michigan MushroomHunters’ Club is an amateur societythat holds forays virtually everyweekend throughout the mushroomseason.

d) Dig up each mushroom you collect toget the entire base. Do not simply cutthe stalk at the soil line. The sac at thebase that enables you to identify apoisonous Amanita may be buriedunder the soil or duff.

e) Take a spore print of each species youcollect (see page 13).

2. Never eat raw mushrooms. Evenmushrooms that are commonly ediblecontain sugars and enzymes that wecannot properly digest and that willcause problems unless they are brokendown by cooking.

3. Never eat old or decaying mushrooms.Many cases of “mushroom poisoning”are actually cases of food poisoning dueto spoilage bacteria contaminating themushroom. Always make sure yourmushrooms are free of insect larvae.Slice through the mushroom from top tobottom to check for insect tunnels.

4. Be careful the first time you eat amushroom. Just as some people areallergic to wheat flour, strawberries orpeanuts, some people are allergic tocertain mushrooms. Do not assume thatbecause you can eat some mushroomssafely, you can eat them all.

5. Any time you sample a new species,save a whole, uncooked specimen inyour refrigerator to aid inidentification in case you should getsick. It is easier for a mycologist orphysician to identify a whole specimenthan to try to make an identificationbased on stomach contents.

6. Try new species one at a time; if you dobecome sick, it is easier to identify theculprit if you ate only one type ofmushroom rather than several types.

7. Do not overindulge. Even the best,safest mushrooms may be difficult todigest if eaten in large quantities. Thefungal cell wall is made of chitin, asugar that we cannot digest.

Stages of white Amanitamushrooms

10 11

8. Respect others. Many people are veryfrightened of any mushrooms that donot come from the store. They wantnothing to do with wild mushrooms, nomatter how safe or delicious themushroom is. Respect this and do notforce your mushrooms on anybody else.

Mushroom biology/mushroom anatomy

To be sure of the identity of a mushroom,we must have an understanding ofmushroom morphology and anatomy. Tosafely identify mushrooms, we must learnto recognize the component parts thatmake it possible to distinguish an ediblemushroom from a poisonous one. Thediagram of the development of apoisonous Amanita at right provides anintroduction to fungal anatomy.

White Amanita mushroomsare poisonous at all stages

a) An Amanita spore lands on a supply offood in a suitable environment. Itgerminates and produces a vegetativegrowth called mycelium composed ofmany fine, hairlike threads calledhyphae.

b) A nodule develops in the mycelium,which will become a button, thenexpand into the fruiting body(mushroom) of the fungus.

a b

c

d

e

f

12 13

c) The egg-shaped button of the Amanita isencased in a thick membrane called auniversal veil. At this stage, it can bemistaken for an edible puffball.

d) The developing mushroom pushesthrough the universal veil membrane,leaving a cuplike structure (the volva)at the base of the stalk. The volva maybe below the surface of the soil or duff.As the stalk elongates, anothermembrane (the partial veil) is evident.It covers the gills beneath the cap,reaching from the stalk to the capmargin.

e) When the cap expands and begins toflatten, the partial veil breaks away atthe margin of the cap but remainsattached to the stalk. The soft membraneattached to the stalk forms a skirt calledan annulus or ring.

f) When mature, the cap may be nearlyflat. The spores have developed andripened on the sides of the gills. The gillsare exposed and the spores can dropfreely into air currents to be carried offto continue the cycle of growth andreproduction. The partial veil hangs as aring on the stalk, and the universal veilforms the volva at the base of the stalk,which may be out of sight beneath thesurface of the soil. This beautiful, purewhite mushroom has earned the titles“angel of death” and “destroyingangel”.

Other mushrooms follow a similar courseof development, with some variations.Amanita species are the only fungi topossess both a volva (universal veil) andan annulus (partial veil).

One very important feature in theidentification of many mushrooms is thespore color. This can easily be determinedby making a spore print. Cut off the cap ofa mature mushroom and set it on a pieceof paper, gill surface down. It is helpful toput a bowl or a glass over the mushroomto keep the mushroom from drying outand to reduce air currents. Leave themushroom for a couple of hours, then liftit off the paper. An accumulation of sporesshould be present. Use white or blackpaper (colored paper can give a distortedimpression). Ideally, you could use a pieceof paper that is half black and half white.Some amateur mushroom clubs have suchpaper available, or it is easy to make someyourself at a copy center. Amanita speciesand many other mushrooms have white tocream-colored spores that will not showup clearly on white paper. Othermushrooms may have colored, darkbrown or black spores.

Spore print

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Mushroom toxins

The vast majority of mushroom poison-ings are not serious. Gastrointestinalsymptoms shortly after ingestion of themushroom are the most commonsymptoms. These may be quite severe andmay cause great discomfort for a day ortwo, but they will usually pass on theirown. In extreme cases, hospitalization maybe necessary to combat dehydration. Ifsymptoms occur within two hoursfollowing ingestion of the mushroom, it isa good sign because the most dangerousmushroom toxins rarely cause symptomsbefore six hours after ingestion.

Each of the major mushroom toxins isdiscussed individually below. Poisindex®numbers are listed, followed by the usualsymptoms and treatment, if known.Poisindex® refers to the Poisindex®system widely used by hospitals andpoisoning centers. This classification maymean nothing to you but will be of help toa poisoning center or physician.

The usual symptoms are listed next,followed by treatment, if known. It is notwithin the scope of this publication toprescribe treatment. When treatments areknown, they will be listed, but in allcases a medical doctor should beconsulted. Many treatments are notavailable outside of a hospital, and self-treatment can be more dangerous than notreatment at all. Further details about thepoisoning follow, as well as the identifyingfeatures of the mushrooms and otheruseful information. Finally, look-alikes arediscussed. If you are collecting mush-rooms for food, make certain that youhave not collected a poisonous species thatresembles the mushroom you want.

Amatoxins (Class A/Poisindex® group 1)

Mushrooms: Certain fungi in the generaAmanita, Galerina, Lepiota and Conocybe.

Symptoms: Severe gastrointestinal distress(stomach cramps, vomiting, diarrhea)begins at least six hours followingingestion. This phase lasts for a day ortwo, followed by a remission in which thepatient feels better. In the third phase, thepatient may fall into a coma or die as aresult of liver and kidney failure.

Treatment: No known antidote. Thestomach can be emptied (emesis or gastriclavage) shortly after ingestion; if morethan two hours have passed, however, thiswill not be effective. Treatment is decidedon a case-by-case basis and involvescareful monitoring of the patient’s liver

Amanita phalloides

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enzyme levels and general condition.Charcoal filtration of the blood may beperformed. Liver transplant may beconsidered.

Description: Amatoxins are smallchemicals technically known as bicyclicoctapeptides. These are responsible for thevast majority of known mushroomfatalities. Amatoxins are found in fungi infour unrelated genera: Amanita, Galerina,Lepiota and Conocybe; all four occur inMichigan. Amatoxin poisoning isparticularly dangerous because symptomsare delayed anywhere from 6 to 36 hoursafter the mushroom is eaten, with anaverage delay of 12 hours. By the time thepatient feels sick, it is too late for emesis orgastric lavage to be of any use.

Amanita species cause the majority ofpoisonings because they are the onlyamatoxin-producing mushrooms that arelarge enough to be tempting to those seekinga meal. Amanita species are usually easy torecognize because of their possession of avolva (cuplike structure) at the base of thestalk, an annulus (ring) around the mid- toupper portion of the stalk, white, free gills,and a white or light-colored spore print(see diagram and photos). Amanita is theonly genus to possess both an annulus and avolva. The volva may be buried in the duff.ANY mushroom being collected for foodshould be dug up out of the ground (not cutoff at ground level) to determine whether ithas a volva. In some species, the volva isfragile and may be lost or destroyed whenthe mushroom is removed. The annulusmay also be fragile and may or may not bepresent in the mature mushroom. To be onthe safe side, be wary of eating anymushroom possessing any of thesecharacters.

Lepiota subincarnata

Galerina marginata

Conocybe filaris(Photo courtesy Mike Wood.)

18 19

Amanita species are usually associatedwith trees, though the association may notbe immediately obvious – the tree may beseveral yards away from the mushroom.Amanita species are common in Michiganparks, woodlands and recreation areasfrom late June until the end of themushroom season in November.

Amanita bisporigera, A. verna and A. virosaare known as the destroying angels. Theseare medium to large mushrooms that areoften a pristine, satiny white. There issome debate about their classification, andthey can be distinguished to species onlywith a microscope. All white Amanitaspecies should be considered deadly.

Amatoxin-producing Lepiota species aresmall (the caps are usually less than 2 inches in diameter). They possess freegills, white spores and an annulus but lacka volva. The Lepiota annulus is looselyattached and can often be slid up anddown the stalk. Young specimens mayhave reddish brown caps; older ones willhave reddish brown scales on a whitebackground. Small Lepiotas are difficult toidentify, and none should be eaten.Despite their diminutive size, these speciescan contain up to 100 times the toxin of amuch larger deadly Amanita.

Galerina and Conocybe species are littlebrown mushrooms and are notparticularly appetizing. Both yield brownspore prints. Galerina grows on decayingwood, while Conocybe tends to inhabitlawns. Conocybe filaris is the only Conocybespecies known to produce amatoxins, butother species may as well; they have notbeen widely tested. Conocybe lactea,common in Michigan, produces a relatedchemical and may produce amatoxins onoccasion. Do not experiment! No Michigan

Galerina is safe. These fungi have causedfewer poisonings than Amanita because oftheir smaller stature and their drabbercolors. Galerina is responsible for periodicpoisonings of people wishing to get highon “magic mushrooms”. Hallucinogenicspecies of Psilocybe are small to moderatelylarge and brown with black spores, andsome people have formed the mistakenopinion that all little brown mushroomsare hallucinogens.

Look-alikes: An edible puffball may beconfused with an immature Amanita in thebutton stage. If you slice it open from topto bottom, the Amanita will show thebeginnings of the stalk, gills and cap of themushroom, while a puffball will simply bea uniform, slightly grainy white or containa mass of yellowish to dark olive-greenspores. Always slice open puffballs to becertain before eating them. ImmatureAgaricus species (meadow mushroom andhorse mushroom) may resemble Amanitasbecause of the whitish free gills, annulusand general stature. The Agaricus will havepink and, eventually, chocolate-browngills with deep brown spores on maturity,while the Amanita will retain whitish gillsand spores throughout. Lepiota(Leucoagaricus) naucina can appear verysimilar to the destroying angels, but theLepiota lacks a volva. Though some bookslist it as edible, L. naucina is notrecommended because it has causedstomach upsets in some people.Chlorophyllum molybdites is a poisonouslook-alike, with white, free gills, anannulus and a similar stature to theAmanita species. The gills turn pale greenin maturity, and the spore print will begreen. Chlorophyllum lacks a volva andpossesses pale tan scales on the cap.

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Cortinarius toxins (Class B/Poisindex® group 1-A)

Mushrooms: Species in the genusCortinarius.

Symptoms: Cortinarius poisoning ischaracterized by an extremely long delay.A minimum of three days, or as long as 10days to three weeks, may pass betweeneating the mushroom and the onset ofsymptoms. Symptoms include vomiting,diarrhea, loss of appetite, headache, afeeling of coldness and eventual kidneyfailure. Kidney failure may lead to death.

Treatment: Treat as kidney failure. Somepatients spontaneously recover; othersmay require dialysis or kidney transplants.

Description: Cortinarius poisoning isparticularly dangerous because of the verylong delay before any symptoms occur.This delay has made it very difficult toidentify precisely which species ofCortinarius may be responsible. Thepoisoning occurs so long after theingestion of the mushroom that it is quiterare for the mushroom to be associatedwith the illness at all. The toxinsresponsible are unknown. Two toxins,both of which can produce disease inlaboratory animals, are assumed to beresponsible for human poisonings.

Cortinarius is the largest known genus ofmushrooms, with well over a thousandspecies. None of them are particularlychoice and, until we know considerablymore about Cortinarius poisoning, noneshould be eaten. The distinguishingfeatures of the genus are the presence of acobwebby veil (the cortina; see photo,page 20) and the rusty brown spores. Thecortina may wear away as the mushroommatures, but a few strands usually remainvisible on the stalk, often highlighted by arusty spore deposit. The gills become rustybrown in age, and a spore deposit mayoften be visible on the caps of adjacentmushrooms. Many (but not all!)Cortinarius species have a swollen,bulbous base. Most species aremycorrhizal and grow in wooded areas.

Look-alikes: The highly desirable blewit,Lepista (Clitocybe) nuda, is purple andresembles several purple Cortinariusspecies. The blewit, however, lacks acortina and has a spore print that iscreamy to pinkish to lilac, never rustybrown.

A representative Cortinarius. Notice the cobwebbycortina covering the gills in these young specimens.

22 23

Monomethylhydrazine(Class C/ Poisindex® group 3)

Mushrooms: Members of the genusGyromitra (false morels).

Symptoms: A latent period of six to eighthours is followed by a feeling of fullness inthe stomach, then vomiting and waterydiarrhea, which may persist for up to twodays. Headache, lassitude, cramps andintense pain in the regions of the liver andstomach may be followed by jaundice. Red

blood cells may be broken down.Poisoning may be fatal.

Treatment: Emesis may help if employedearly (more than two hours after ingestionit will have no effect, so it will beineffective by the time symptoms occur).Fluid replacement may be necessary ifpatient is dehydrated. Patient should behospitalized so laboratory tests can beperformed to detect signs of hemolysis orliver or kidney failure.

Description: Monomethylhydrazinepoisoning is among the most confusingmushroom poisoning syndromes. Theamount of toxin can vary greatly frommushroom to mushroom, andsusceptibility can vary greatly from personto person. The method of preparing themushrooms makes an immense difference.The toxin is volatile and is destroyed byheating. The “safest” way to prepareGyromitra species is to parboil themushrooms (being careful not to inhaleany of the vapors, which will contain thetoxin), discard the cooking water and frythe mushrooms in a separate, clean pan.This removes the majority of themonomethylhydrazine. Other toxins,including an unidentified carcinogen,remain in the mushroom and can build upover time with repeated Gyromitra meals.Despite the fact that many people persistin deliberately gathering and eating thesemushrooms, we do not recommend eatingany Gyromitra species.

Mushrooms in this genus are verydistinctive. The cap is some shade ofbrown and is on a whitish to pale tanstalk. The cap may be wavy, convoluted orlobed, but it is not pitted. There are nogills. Gyromitra is an Ascomycete; it

Gyromitra esculenta

Coprinus atramentarius

24 25

belongs to a very different group of fungithan the other mushrooms in thispamphlet and is related to the morels. Nospore print will be obtainable. If you sliceopen the mushroom from top to bottom,the attachment of the cap to the stalk isdistinctive. Unlike most mushrooms,which fruit in the late summer or fall,Gyromitra fruits in the spring.

Look-alikes: Morels (Morchella species).True morels are readily distinguished fromthe false morels by the possession of apitted (not lobed or wavy) cap and by theattachment of the stalk. The stalk isattached to the base of the cap in the truemorels but to the top of the cap in the falsemorels. See MSU Extension bulletin E-2755, May is Morel Month in Michigan, for more information.

Coprine (Class D/Poisindex® group 5)

Mushrooms: Coprinus atramentarius,Clitocybe clavipes, other Coprinus species(rarely).

Symptoms: Symptoms may occur shortlyafter the consumption of an alcoholicbeverage plus the mushroom or onconsumption of alcohol up to 48 hoursafter the mushroom is eaten. Symptomsinclude a flushing of the face and neck, ametallic taste in the mouth, tingling of theextremities, rapid heartbeat and a feelingof swelling in the face and hands. The

initial symptoms may be followed bynausea and vomiting. Occasionally visualdisturbances, vertigo, weakness andconfusion occur.

Treatment: The symptoms will subside ontheir own in time. Reassure the patient,who may be convinced that he or she hasbeen seriously poisoned.

Description: Coprine is interesting in thatit is not, strictly speaking, a poison. Manypeople can and do eat these mushroomswith no ill effect. Alcohol, on the otherhand, is a poison. The human body dealswith alcohol by quickly degrading it into aseries of less toxic compounds until it is nolonger harmful. Coprine interferes withthis process by inhibiting one of theenzymes used in alcohol processing.Alcohol is broken down partway, toacetaldehyde, but is not completelyprocessed. The symptoms of coprinepoisoning are due to the buildup ofacetaldehyde in the blood. Incidentally,disulfiram, which is used to treatalcoholism, operates in the same manner.

(Photo courtesy Tom Volk.)

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Coprine poisoning is not serious, though itis unpleasant and can be alarming to thevictim, who may believe that he or she haseaten a truly dangerous mushroom. Thepoisoning will usually run its course in acouple of hours without any additionaltreatment. The mushroom responsible, Coprinusatramentarius, belongs to the black-sporedmushroom group known as the inky caps.Shortly after the mushroom matures, thegills begin digesting themselves from thebottom edge up and the gills and capdissolve into ink, colored black by thespores. Coprinus atramentarius is amongthe larger Coprinus species and possesses asmooth to finely silky, gray-brown cap.The cap doesn’t expand nearly so much asthat of many other mushrooms andalways remains broadly conical. Themushroom commonly occurs in largegroups at the bases of street trees or ingrass, and we have frequently seen itfruiting on lawns and boulevards in EastLansing in the summer and fall. Coprinusatramentarius is edible and safe if cookedand if no alcohol is ingested within two orthree days of eating the mushroom. AllCoprinus species should be cooked andeaten very shortly after being picked,before they have a chance to autodigest.

Look-alikes: The black spores and thetendency to dissolve into ink aredistinctive. Coprinus commatus, the shaggymane, is a popular edible species, but itpossesses a white, cylindrical, scaly capand is not likely to be mistaken for C. atramentarius.

Psilocybin, Psilocin (Class E/Poisindex® group 6)

Mushrooms: Psilocybe and Strophariaspecies, Paneolus species, some Conocybeand Inocybe species, Gymnopilus spectabilis.

Gymnopilus spectabilis(Photo courtesy Mike Wood.)

Paneolus(Photo courtesy Alexander Smith.)

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Symptoms: A change of mood usuallyoccurs beginning 20 to 60 minutesfollowing ingestion of the mushroom. Thepatient may experience fear, excitement,hilarity, hallucinations, loss ofcoordination, dilation of pupils, rapidheart rate or rapid breathing. Childrenmay develop a high fever and/or seizures.

Treatment: Reassurance and time areusually sufficient treatment. Childrenshould be monitored and may requirehospitalization in case of fever or seizures.Poisoning is rarely serious in adults, and,because of the disordered state of themind, moving a hallucinating patient tothe hospital may increase his or her senseof fear and confusion.

Description: With the exception ofGymnopilus, which is a large, yellow-brown mushroom growing in clusters onwood, psilocybin-containing species aresmall to moderately large brownmushrooms with dark brown to purple-black spores. Many of these species bruisebluish or are bluish at the base of the stalk.They can grow in lawns, meadows(particularly highly fertilized ones) or onmanure.

Little brown mushrooms are not generallysought as food. Those who seek out andeat these deliberately are usually lookingfor hallucinogenic species. The primarydanger is from toxic species that may looksimilar. Because these can fruit on lawns,they are also responsible for several childpoisonings, though we have not heard anyreports of this in Michigan.

Look-alikes: Gymnopilus is larger thanmost psilocybin-containing species. Itgrows in clusters on wood and is common

in Michigan. We have seen G. spectabilismistaken for the honey mushroom,Armillaria mellea. The two can bedistinguished by the spore color, which isyellow-brown in Gymnopilus and white inArmillaria. Gymnopilus also resembles thepoisonous Omphalotus illudens.

The deadly poisonous Galerina specieshave been mistaken for Psilocybe species.Galerina grows on wood, not on soil orlawns (though there are rare reports ofGalerina growing on buried wood ingrass). Galerina has a bright brown toorange-brown spore print and maypossess a small annulus.

Muscimol, Ibotenic Acid(Class F/ Poisindex® group 2)

Mushrooms: Primarily Amanita muscariaand A. pantherina, but similar toxins mayoccur in A. cothurnata, A. frostiana and A. gemmata.

Symptoms: A feeling of drowsiness 30 to60 minutes after ingestion, followed by astate resembling alcoholic intoxication.Following this, a hyperactive state ofconfusion, muscular spasms, delirium andvisual hallucinations occurs, lasting aslong as four hours. Vomiting usually doesnot take place. Drowsiness and deep sleepfollow, and recovery is usually quite rapid,though a fatality rate of 1 to 5 percent isreported.

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Treatment: Usually symptoms subside intime; overtreatment can be moredamaging than none at all. Emesis orgastric lavage may be performed if thepatient is brought in early on in thepoisoning.

Description: Ibotenic acid occurs in themushrooms. Muscimol, which causes thesymptoms of the poisoning, is producedby the body’s efforts to process ibotenicacid. Muscimol is thought to bind toreceptors in the brain, causing disorderedneurotransmission. Amanita muscariacontains less of the toxin and is thereforeless dangerous than A. pantherina. Theother species are less well studied andhave rarely been eaten.

Amanita muscaria is the red-cappedmushroom with white spots or patchescommonly depicted in folk art. The red-capped variety is rare in Michigan, but anumber of other varieties occur, includingones with yellow, orange or white caps.All varieties have whitish, removable“warts” on the cap when young, thoughthese may wear off or be washed off inage. The volva is not obvious and cuplike,

as in the destroying angels, but appears asa series of concentric rings on the stalk,just above the swollen base. Like otherAmanita species, it is mycorrhizal withtrees and is thus usually found in thewoods and clearings near trees, though wehave seen A. muscaria under white pine inresidential settings. Amanita pantherinalooks similar to A. muscaria but has agrayish brown cap covered with similarwhitish to grayish patches.

The people poisoned by these mushroomsare usually children, who may be attractedby the bright colors of A. muscaria and its“friendly”, familiar appearance, andpeople deliberately seeking hallucinogenicsubstances. Rarely, people will mistake A. muscaria for the edible A. caesarea. A. muscaria occurs worldwide and hasbeen widely used as a hallucinogen inparts of Europe and Asia. North Americanmushrooms have a somewhat differentarray of chemicals and are more likely tobe seriously poisonous than Old Worldspecimens; consequently, A. muscaria hasnot been so widely used as a hallucinogenhere. Loss of muscular control may bepronounced. Fatal poisonings are morelikely to occur with A. pantherina, whichcontains higher levels of toxin than A. muscaria.

Look-alikes: The edible and popularCaesar’s mushroom, Amanita caesarea, hasa reddish orange cap and may have whitepatches on the cap, though A. caesarea islikely to have one or two large patches andA. muscaria more often has many smallpatches. Amanita caesarea has bright yellowgills; those of A. muscaria are white to palecream. Poisonings have occurred becauseof confusion between these two species,especially among European immigrants.

Amanita muscaria

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Muscarine (Class G/Poisindex® group 4)

Mushrooms: Certain members of thegenera Inocybe and Clitocybe.

mushrooms. For severe cases, atropinemay be administered by a physician. Thisis the only mushroom poison for which aspecific antidote is known.

Inocybe species are often called “fibercaps”. Their caps and stalks are oftenfibrous, with fibers radiating out from thecenter of the cap visible to the naked eyeor with a magnifying glass. Sometimes thecaps may look silky. Caps tend to beconical. The caps are mostly dull gray, tanor brown. The spore print is yellowishbrown, and the mature gills will be tan tobrownish. Clitocybe species have whitespores. Clitocybe dealbata is a small, palemushroom with a slightly rounded cap;other Clitocybe species often have anupturned, funnel-shaped cap with the gillsrunning partway down the stem(decurrent gills). Both Inocybe andClitocybe species may fruit in lawns.

Look-alikes: These are mostly smallmushrooms, which are not likely to beeaten by most people. Marasmius oreades,the fairy ring mushroom, may resembleClitocybe dealbata, and the two may growintermingled. Marasmius oreades hasrelatively few gills, which are quite thickand widely spaced and may have visibleveins between the gills, while Clitocybe hasmany, thin, crowded gills.

Symptoms: “PSL” (perspiration,salivation, lacrimation) or “SLUDGE”(salivation, lacrimation, urination,defecation, gastritis, emesis) syndromeoccurs beginning 30 to 120 minutesfollowing ingestion.

Treatment: Atropine is a specific antidotefor muscarine poisoning. Atropine is toxicand should be administered only by aqualified physician.

Description: The PSL syndrome is notusually particularly dangerous but isdecidedly unpleasant. There are norecorded deaths due to poisoning by these

Inocybe species(Photo courtesy Mike Wood.)

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Unknown toxins (Class H/Poisindex® group 7)

“Unknown toxins” is a catch-all term tocover any toxin that doesn’t fall into theabove categories. These are gastro-intestinal irritants unless otherwise noted,and symptoms consist of abdominalcramps, nausea, vomiting and/or diarrheastarting between 30 minutes and twohours after ingestion. Because the exactnature of the toxin is unknown, no specificantidote can be recommended. Treatmentis time and reassurance. The commonMichigan mushrooms in this category willbe covered.

Chlorophyllum molybdites (green gill)

The defining features of this large,attractive mushroom are the green gillsand green spore print. The gills turn green

as the mushroom matures, so youngspecimens may still have whitish gills. Thegreen spore print is diagnostic – no othergilled mushroom in Michigan has greenspores. Chlorophyllum molybdites alsopossesses a ring around the stalk but,unlike Amanita species, it has no volva. It can fruit on lawns, and we have seen alarge fruiting on the Michigan StateUniversity campus in July. This mushroomis very similar to the edible Lepiotaracchodes and L. procera (C. molybdites issometimes called Lepiota morganii). Theonly observable difference between C. molybdites and L. racchodes is the sporecolor: the Lepiota has white spores.

Lepiota (Leucoagaricus) naucina

Many books list this species as edible, butmany people are unable to eat it withoutstomach upset, so it should be avoided. Itis dingy white when young, maturing to atannish off-white color. It possesses a smallring on its stalk and can be mistaken forthe destroying angels. There is no volva,but the base is swollen. Spores are white orrarely pinkish. It usually grows in grassand can show up in lawns. L. naucinashould not be gathered because of the

Chlorophyllum molybdites

Lepiota (Leucoagaricus) naucina (Photo courtesy Tom Volk.)

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chance of an adverse reaction and themore serious risk of accidentally gatheringa deadly Amanita.

Omphalotus illudens(Jack o’lantern)

Entoloma species

These species are characterized by a pinkto red spore color and angular spores(visible under a microscope). Most speciesare poisonous. Many books will list asedible Entoloma abortivum, which occurs inassociation with the honey mushroom,Armillaria mellea. To make mattersconfusing, both the aborted and non-aborted forms (see picture) are called E. abortivum, but the aborted form isactually primarily the honey mushroom,which is being parasitized by the Entoloma.The aborted fruit bodies are edible; non-aborted Entolomas should not be eaten,because of the possibility of confusionwith poisonous species. Entolomaabortivum grows on or near wood in thefall; other Entoloma species grow on theground in humus in wasteland and fields,along edges of bogs and in woodlandareas. Many small species grow on rottingwood. They can be found during allseasons from early spring until late fall.

Mushrooms are medium to large andgenerally occur in clusters on wood or atthe bases of trees. Fresh specimens possessthe distinctive character of biolumin-escence – their gills can glow in the dark.Gills, like the rest of the mushroom, rangefrom orange to yellow-brown and maydescend partway down the stalk. Thespore print is creamy white.

These mushrooms have been mistaken forArmillaria mellea, the popular honeymushroom, which also occurs in clusterson wood or at the bases of trees. Armillariamellea is part of an extremely variablespecies complex, but specimens usuallypossess a ring around the stalk, whichOmphalotus lacks. Armillaria mellea haswhitish (not orange) gills and forms black,shoestring-like organs called rhizo-morphs, which may often be visibleextending from the base of the mushroom.

Omphalotus illudens

Entoloma abortivum. Aborted form on left.

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Paxillus involutus (roll-rim) are often too thin or woody to eat. Theboletes are soft and mushroom-shapedwith a stalk that is often thick or swollen.The stalk may possess netlike markingsand ridges (reticulations). The cap is oftenvelvety, though it may be smooth, felty orslimy. Boletes include many popular foodmushrooms, such as Boletus edulis, knownvariably as the king bolete, porcini, cep orsteinpilz. Boletes are enthusiasticallycollected by many Europeans.

Boletes that have red to red-orange poresand/or stain blue should be avoidedbecause most are poisonous. The stainingreaction can be easily observed by cuttingthe mushroom or the pore surface with aknife. This reaction can be quite dramatic(see picture). See MSU Extension bulletinE-0926, Best of the Boletes, for furtherinformation.

The cap is slightly depressed in the centerand the edges of the cap roll over (seepicture). Gills and cap range fromyellowish brown to brown; gills run downthe stalk, which is comparatively thick.The mushroom is common in lawns and inwoods in the fall. Paxillus involutus iscommonly eaten in eastern Europe, whereit is pickled. It is frequently responsible forgastrointestinal distress and can also giverise to a rare but serious allergic reaction.In some few individuals – usually peoplewho have been eating P. involutus for years– an antibody will form to an unknownantigen in the mushroom. The next timethe person eats the mushroom, theantibody and antigen interaction willcause red blood cells throughout the bodyto break down.

Red-pored blue-staining boletes

Boletes differ from other mushrooms inhaving a spongy layer of pores instead ofgills. Other fungi, such as the shelf fungithat grow on wood, may have pores but

Paxillus involutus(Photo courtesy Mike Wood.)

Boletus subtomentosus

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Laetiporus sulfureus (chicken ofthe woods; sulfur shelf)

This is a shelf fungus rather than a truemushroom. When fresh, it is brilliant,bright yellow or yellow-orange and is verysoft and often surprisingly heavy (much ofits weight is water). In this young stage, itis often collected for food. Many people,however, are sensitive to some unknownchemical in the fungus and suffer gastricdistress when they eat it. The mushroomgrows on wood, and the substrate appearsto have some effect on toxicity: thosegrowing on conifers or locusts arefrequently toxic. If you eat this mushroom,do not eat much the first time you try it.Do not serve L. sulfureus at largegatherings.

you know the mushrooms, be sure youare prepared for collecting. Carry acompass anytime you go into thewoods, and know how to use it. Dressproperly. Keep track of the time, andallow enough time to get out of thewoods before dark.

3. Not unless you are absolutely certainthe mushroom is safe to eat. Collectcarefully and do not mix collections ofdifferent species. A shallow basket or amesh bag is best for collecting, andindividual collections should bewrapped in wax paper. Never useplastic – it causes the mushrooms todecompose quickly. Promptly clean,refrigerate, cook or preserve yourcollection upon returning home. Unlessyou intend to use the mushrooms,please don’t pick them.

Report poisonings

It is important to report any case ofdistress from eating a mushroom,particularly if you can describe or identifythe mushroom. In Michigan, report to theDeVos Children's Hospital, RegionalPoison Center, 1300 Michigan, Suite 205,Grand Rapids, MI 49506; (800) 222-1222(national number – will connect you to thenearest poison control center).

Should you collect wild mushrooms?

1. Not unless you are willing to study untilyou learn the positive identification ofthe mushroom you seek.

2. Not unless you assume theresponsibility for your own safety andwell-being. In addition to making sure

Laetiporus sulfureus

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Human poisoning centers

Statewide and Western Michigan 1-800-222-1222DeVos Children's Hospital Regional Poison Center1300 MichiganSuite 205Grand Rapids, MI 49506

Upper Peninsula1-800-222-1222U.P. Poison Crisis CenterMarquette General Hospital420 West Magnetic StreetMarquette, MI 48955

Eastern Michigan1-800-222-1222Poison Control CenterChildren's Hospital of Michigan 3901 BeaubienDetroit, MI 48201

Additional resources

Amateur mycological societies provide asetting in which you can meet and learnfrom others who share your interest inmushrooms. The Michigan MushroomHunters’ Club has forays nearly weeklythroughout the mushroom season.

Michigan Mushroom Hunters’ Club:<http://www.sph.umich.edu/~kwcee/mmhc/>.

North American Mycological Association:<http://www.namyco.org>.

Tom Volk’s Fungi:<http://www.TomVolkFungi.net>.

MykoWeb:<http://www.mykoweb.com>

Benjamin, Denis R. 1995. Mushrooms:poisons and panaceas. New York: W. H.Freeman and Company.

Scates, Kit. 1983. Diagnosis and treatmentof mushroom poisoning on basis ofsymptoms and mushrooms. Poster.

Spoerke, David G., and Barry D. Rumack(eds). 1994. Handbook of mushroompoisoning: Diagnosis and Treatment. BocaRaton, Fla.: CRC Press.