by Greg Marley
Melt the butter in a heavy Dutch oven and add the onions to cook over low–medium heat till translucent (4–5 minutes). Add the flour and the chopped mushrooms and continue cooking until the mushrooms release their liquid.
Add the stock slowly and bring to a boil. Reduce heat and allow to simmer for 15 minutes.
Ladle half of the soup into a food processor, puree using steel blades, and return it to the soup pot.
Add the white wine and cream in separate batches and warm the soup thoroughly, but do not boil. Season with salt and pepper. Serve in bowls garnished with parsley and perhaps a nice grating of cheese.
Once again, this basic mushroom soup can be adapted to many different species of wild or cultivated mushrooms. The recipe works well with portobella or crimini mushrooms.
MUSHROOM COUSCOUS
Couscous is the primitive pasta almost ubiquitous in the North Africa and some Mediterranean countries. Like many pastas, it adapts to almost any combination of flavors. Though I have made this recipe for Agaricus, it can be subtly shifted to meet the needs of almost any edible species including chanterelles, porcini, morels, Maitake, chicken mushroom, and others. Have fun with the mix of other ingredients.
2 tablespoons olive oil
½ green or red bell pepper, chopped
½ cup chopped celery
½ cup onion
2 garlic cloves, minced
1½ pounds meadow mushrooms (or another compatible species)
Basil and parsley, finely chopped
2 cups couscous
2 cups boiling water or stock
½ cup white wine
Sea salt and freshly ground pepper
Grated cheese for garnish
I use a high-sided or deep skillet for this and do all cooking in the same pan. Heat pan over medium fire, adding oil followed by onions, garlic, pepper, and celery. Sauté for a minute or two and add the chopped mushrooms. After the mushrooms begin to lose their water, add the salt and pepper along with the dry couscous and continue to heat. Add the hot stock and the wine, briefly stir to evenly distribute the liquids, turn off the heat, and cover with a tight fitting lid. Allow to sit for 10 minutes and then serve with the chopped herbs as garnish. The additional garnish of grated hard cheese and freshly ground pepper is an added bonus.
PART III
DANGEROUSLY TOXIC,
DEADLY INTERESTING
Introduction
POISONOUS MUSHROOMS
Not as Bad as You Fear
Fungi ben musheroms;
there be two manners of them,
one manner is deedly and
slayeth them that eateth them
and be called tode stoles,
and the other doeth not.
THE GRETE HERBALL, 1526
T he horror stories abound: tragic tales of poor souls who mistakenly ate the wrong mushroom and were found dead in their beds. People sometimes tell me anecdotal accounts of entire families that died following a meal of mushrooms the night before. Even knowing that such stories must be false, I still find them both frightening and compelling. The reality is that there are cases of several members of a family dying from poisonous mushrooms, though never within twenty-four hours. Deadly mushrooms have a delayed onset of symptoms and take days to kill the victims.
Still, deaths by poisonous mushrooms are rare, in spite of growing concern that mushroom poisoning is on the increase. The perceived risk far exceeds the reality. Though medical providers see several thousand people each year due to concerns regarding mushroom poisoning, almost none of those people die and very few require medical intervention beyond activated charcoal and anti-emetics, if medical intervention is needed at all. The national network of Poison Control Centers handles 8,000–10,000 mushroom-related calls each year, almost 80 percent related to toddlers or young children.1 Of those mushroom calls made to Poison Control Centers, fewer than 5 percent develop moderate or worse symptoms requiring significant hospital emergency room intervention, and fewer than1 percent are considered severe, requiring inpatient hospital admission. For the thirty years ending in 2005, one or two people per year, on average, died of mushroom poisoning in America.2 There was a surprising increase in 2009, when five people died of mushroom poisoning in the United States and Canada, according to preliminary reports compiled by the North American Mushroom Association (NAMA) Toxicology Committee chair Michael Beug. Four of the deaths were from amatoxins and the last, a man in his nineties, died from complications related to eating a type of bolete.3 Still, despite the increase in 2009, compared to the number of people injured and killed each year by lightning (about 100), bee or wasp stings (30–50), or peanuts (up to 100), mushrooms are quite safe.
But while it’s important to put the risk of mushroom poisoning into perspective, it’s also important never to dismiss that risk. Several times over recent years I have identified poisonous jack o’lantern mushrooms in cases where a very sick person was certain that they had collected and eaten chanterelles. The green-spored Lepiota, Chlorophyllum molybdites, causes moderate to severe gastrointestinal anguish to several dozen people each year and consistently leads the list across America for the most frequent cause of mushrooming malaise.4 If you never eat a wild mushroom, you’ll never be poisoned by one, but if you aspire to eat wild mushrooms, it is vital that you acquaint yourself with this darker side to mushroom foraging.
If the emerging mycophagist acts responsibly, acquires good basic mushroom identification skills, and learns the common edible and common toxic species in his or her area, there is little risk of a bad experience. This is especially true for someone collecting and eating only common, easily recognized mushrooms like chanterelles, morels, or puffballs and avoiding the temptation to practice extreme mushrooming where the goal is to develop the longest list of different mushrooms eaten.
This section is in no way a comprehensive treatment of the toxic mushrooms in any region of America. There are plenty of great books, articles, and Internet sites that can fill that need. Rather, the goal is to look at commonly encountered scenarios in mushroom poisoning and suggested strategies for avoiding those pitfalls, as well as to underscore the worst-case scenario by looking at the death cap, the deadliest mushroom in the world. I’ll also take a look at the ever increasing body of knowledge on the interaction of mushroom toxins in the human body. There are several mushrooms with significant histories as edibles, especially in Asia and Europe, that we now know are capable of triggering life-threatening illness and even death. When this happens with a mushroom that has an extensive history of collection and consumption, people’s resistance to accepting the change in status can be significant. We will take a close look at three mysterious cases of mushrooms that have long edible histories and examine the information that has come to light and tarnished their status.
7
MUSHROOM POISONING
The Potential Risks and Ways to Avoid Them
I confess, that nothing frightens me more
than the appearance of mushrooms on the table,
especially in a small provincial town.
ALEXANDRE DUMAS
Mycologists, medical doctors, and poison control specialists who track mushroom poisoning cases have a pretty clear idea of what they consider a poisonous mushroom. A mushroom is considered toxic if it produces a predictable set of negative reactions in a significant percentage of the people who eat it.
It sounds straightforward, right? And for some species, it is. The death cap, Amanita phalloides, is responsible for at least 80 percent of mushrooming deaths in Europe and is increasingly problematic in the United States.1 The related destroying angels, A. bisporigera and A. virosa (see #12 in the color insert), are less potent but equally dangerous. No one questions the universal toxicity of these amatoxin-containing mushrooms.
For most mushrooms, though, it isn’t that simple. First of all, how do you define a predictable set of negative reactions? Second, how many sick people does it take to reach the level of sign
ificant? Some common and favored edible mushrooms cause problems for a small percentage of the people who eat them. A 2006 compilation of mushroom poisonings includes reported reactions to morels, chanterelles, and honey mushrooms.2 Reactions to these popular mushrooms are generally fairly mild and occur only in a very small percentage of the many thousands of Americans who eat them, so they’re not considered toxic by most mushroom experts, although as you can see in this book, responsible mycologists will note the existence of the small risk. Though estimates vary, there are up to 400 toxic mushrooms worldwide,3 based on all reports of people’s negative reaction to eating fungi, including reports on many mushrooms that most people eat without problems. A person can have or develop a bad reaction to a mushroom that the next 99 people enjoy without problems. These “idiosyncratic” reactions happen, but are difficult to use as an assessment of toxicity generalized to all people. The list of mushrooms with proven, consistent toxicity is much smaller, and many good mushroom field guide authors differentiate between a mushroom that has caused problems with a few people and those that sicken most people who eat them. The list of toxic mushrooms commonly found in any region—such as the following sidebar on common toxic mushrooms of the Northeast—will be even smaller. Many of the toxic mushrooms found in the Northeast, or related species, also are found in other regions of the United States.
In the classes I teach and the mushroom walks I lead, a few people regularly question my judgment regarding some mushrooms I refer to as poisonous. Their query is generally along the lines of “I’ve eaten that mushroom many times over the years without problems. It’s not poisonous,” they say. It’s difficult to argue in the face of such persuasive first-person advocacy; however, mushroom chemistry is complex and people’s food tolerances and vulnerabilities are equally complex with a number of variables coming into play. A mushroom earns the label of toxic over time, when a number of people report a bad reaction associated with eating it. Alternately, a mushroom may be labeled as poisonous if only a small number of people have died or suffered life-threatening illness due to eating it. The number of complaints needed to trigger the labeling has never been defined and there is a lot of folk wisdom involved, since the labeling of edibility and toxicity develops over generations and around the world.
For other species, including some with extensive histories of culinary use, the method of preparation can mitigate the toxicity. The false morel, Gyromitra esculenta, (see #13 in the color insert) contains highly toxic and carcinogenic hydrazines and is responsible for serious illness and deaths in Europe, and some cases of severe poisoning in the United States. Yet this mushroom and closely related species are eaten and highly prized by thousands in Europe and western North America. (See Chapter 9 for the full story.)
A couple of mushroom species are good edibles and people frequently eat them, but they can cause illness if the diner drinks alcohol during or after the meal. Coprinus atramentarius, known in England as tippler’s bane and in the United States as the alcohol inky, causes a reaction similar to Antabuse (the trade name of disulfiram), which is used to treat chronic alcoholics by helping them avoid the temptation to drink. The effects of drinking alcohol with tippler’s bane include flushes, sweating, nausea, vomiting, racing heart, and general feelings of malaise, as with Antabuse. Symptoms generally abate within eight hours but can return if alcohol is again imbibed for up to seventy-two hours after a meal of these mushrooms. Interactions with alcohol also have been noted with morels, chicken mushroom, and a few others on very rare occasions. Although alcohol inkys are often categorized as toxic, it could be just as easily argued that the alcohol inky is edible and the alcohol is toxic.
Common Toxic Mushrooms of the Northeast*
Dangerously toxic:
Amanita virosa and A. bisporigera, destroying angels
Amanita phalloides, death cap
Conocybe filaris, deadly conocybe
Gyromitra esculenta, false morel and related species
Galerina autumnalis, deadly galerina and related species
Lepiota josserandi and L. castanae
Paxillus involutus, poison pax
Pleurocybella porrigens, angel wings
Moderately toxic:
Clitocybe dealbata, the sweating mushroom
Entoloma lividum (sinuatum)
Inocybe spp., especially fastigata and geophylla, fiber caps
Hebeloma crustuliniforme, poison pie
Naematoloma (Hypholoma) fasciculare, sulfur tuft
Omphalotus olearius, jack o’lantern mushroom
Mild to moderate toxicity (generally gastrointestinal):
Agaricus xanthodermus, A. placomyces
Amanita brunescens, A flavoconia, A. flavorubens, A frostiana
Boletus sensibilis and B. subvelutipes, red-pored blue staining boletes
Chlorophyllum molybdites, green-spored Lepiota
Gomphus floccosus, scaly vase chanterelle
Hygrocybe conica, black-staining Hygrocybe
Lactarius chrysorrheus, L. rufus, L. torminosus, milky caps
Lepiota cristata
Pholiota squarrosa (toxic for some)
Ramaria formosa and some related species, coral mushrooms
Russula emetica, R. nigricans, R. densifolia, and other black-staining species
Scleroderma spp., earth ball or pigskin puffball
Tricholoma pardinum and others
Tylopilus eximius, lilac brown bolete
Toxic under certain circumstances:
Clitocybe claviceps, clubfoot Clitocybe (for some, if consumed with alcohol)
Coprinus atramentarius, alcohol ink cap or tippler’s bane
(with alcohol),
Morchella spp., morels (with alcohol, for a small percentage of folks)
Hygrophoropsis aurantiaca, false chanterelle, (edible, but causes problems for some)
Toxic unless completely cooked:
Armillaria mellea complex, honey mushroom
Lepista nuda, blewit
Morchella spp., morels
Laetiporus sulphureus complex, sulphur shelf
Hallucinogenic or inebriating:
Gynnopilus spectabilis, big laughing gym, G. validipes and related species
Psilocybe semilanceata, liberty cap, and other species
Amanita muscaria, fly mushroom, A pantherina, A. crenulata, and others
Panaeolus foenisecii, the lawn mowers mushroom, and other species
Edible, even esteemed by some, but problematic for a very small minority:
Armillaria mellea complex, honey mushroom
Laetiporus sulphureus, sulphur shelf or chicken mushroom
Morchella spp., morel
Suillus luteus and other viscid-capped Suillus
* This table is in no way intended to be a comprehensive listing of toxic mushrooms4
There are mushrooms eaten and enjoyed by the overwhelming majority of diners, including the very popular edible honey mushrooms, Armillaria mellea complex, and sulfur shelf, Laetiporus sulphureus. Yet some people, probably less than 5 percent of the population, are unable to tolerate these mushrooms and have a mild to moderate gastrointestinal upset following a dinner with them. Does that make these species poisonous? If you happen to be one in the 5 percent, you might think so, but you would quickly learn to avoid the offending mushroom, as you would with strawberries, peanuts, or shellfish due to allergic reaction. The difference is that since the majority of people have a positive association with and a long history of eating strawberries, we do not paint all strawberries with the broad brush-strokes of suspicion as is often the case with wild mushrooms in the United States.
Finally, there are a few good edible mushrooms that will sicken most people who eat them raw or undercooked. These species contain a heat-labile toxin removed or neutralized by cooking. The popular edibles morels, honey mushrooms, and blewits are included in this group. When properly cooked, they cause no problems. The similarity is to foods like meat that are unsafe when eaten raw or
undercooked.
Almost all mushroom field and cooking guides instruct the mushroom hunter to fully cook wild mushrooms before eating. In addition to those mushrooms with heat-neutralized toxins, this is necessary due to the structural make-up of mushroom cells. The combination of chitin and the long-chain complex polysaccharides that comprise the majority of the mushroom cell walls make them largely indigestible unless they are cooked. The heat of cooking starts to break down the complex cell structure and enables us to take advantage of the nutritious proteins, carbohydrates, and vitamins in the mushrooms. Even when mushrooms are fully cooked, our digestive tracts are unable to break down much of the mushroom cell wall components. Most of the glucan polysaccharides and chitin are passed through the gut as fiber, which is a necessary dietary component and helpful in lowering cholesterol, not to mention its assistance in maintaining regularity. (I love that word.) Some of these same polysaccharide glucans stimulate the functioning of the human immune system and are being used around the world as immune stimulants and as an aspect of cancer therapies.
Because they are basically indigestible, uncooked mushrooms are treated as unfriendly tenants in the gut, and overindulgence may trigger nausea and vomiting. It is generally accepted in the mushroom poisoning field that mild cases of gastrointestinal distress are often due to an individual’s difficulty digesting the meal rather than any toxin in the mushroom. This is especially true if the mushrooms were not thoroughly cooked, but also can happen with good old-fashioned gluttony. If you come across a huge basket of honey mushrooms, remember that you don’t need to eat them all in one meal.
A few years ago, a former neighbor of mine expressed her interest in trying wild mushrooms. I gave her a portion of a large fruiting body of hen of the woods, Grifola frondosa, and explained how I normally prepare it. Over the course of the day, as she passed the mushroom lying on her kitchen counter, she began breaking off small pieces of the firm, gray, spoon-shaped caps and eating them raw. She later reported liking the crispness of the texture and the mild flavor. Several hours later, she started to feel quite nauseous and became violently ill for a short time. After emptying her stomach, she fairly quickly recovered and, after talking to me and realizing her mistake, she cooked some of the mushroom the following day and ate it without problems.
