I live in Asheville, North Carolina, where I've been teaching about wild mushrooms and harvesting them commercially for over ten years. Several hundred pounds a year, in fact, for over thirty restaurants– and I haven't lost a customer yet. Fall of 2006, however, I made my first obvious mistake. I say "obvious" because poisoning isn't always pronounced, as I'll explain below. This time, however, it was clear that something had gone wrong; just what went wrong was not so clear. Here's what I figured out and what I learned– the hard way.
I learned that there are at least nine differences between the parasol mushroom, Macrolepiota procera, and the green-spored parasol, Chlorophyllum molybdites. I also learned– or was reminded, rather– not to serve more than one questionable mushroom at a given meal. I'll recount just what happened in part one and how to tell M. procera from its toxic twin in part two.
On a lovely night in late September, I shared a mushroom meal with three friends. Two hours later, the first started retching repeatedly. This lasted for three hours. An hour after that, guest #2 started experiencing achy muscles, headache, kidney pain, weakness and slight constipation. His low energy lasted for several days. I found myself thinking ironically, thank God the people I poisoned are my friends!
The third guest had symptoms similar to the second but far less severe. And me? I noticed little or no symptoms. Granted, I felt exhausted, even like I was getting sick. But I had just come off of a packed teaching and gathering season, driven four hours to Chapel Hill, and stayed up late the night before. By the next morning I felt fine– physically, at least.
It took a while to figure out what had happened not only because the four of us reacted differently but because we had eaten several different mushrooms. Besides serving what must have been a green-spored parasol, mixed in with two "true" parasols (M. procera), I also cooked up two puffballs (Calvatia cyathiformis/craniiformis), a good-sized gilled bolete (Phylloporus rhodoxanthus), and one large two-colored bolete (Boletus bicolor). It turns out that as far as we can tell, at least two of these were toxic to at least two of us.
At first, however, every mushroom we ate was suspect in some way. In fact, it looked as if I could well have made not one but four mistakes in one meal: wrong identification, eating something in poor condition, eating something contaminated, and serving more than one species known to be "edible with reservations" (which doesn't mean calling ahead). I will discuss each of these arguable ingredients in turn (I can just see myself on "Mycologist's Most Embarrassing Moments").
The gilled bolete we ate was the youngest of three collected. If you know the gilled bolete, you know it's hard to find fresh ones (at least on the east coast), which is why I was looking forward to eating them. Not surprisingly, on later examination the other two proved to be slightly moldy. Compared to what else we ate, however, I doubt this was the problem.
Next was the puffball platter. The classic instruction regarding puffballs is to eat only those that are still pure white inside. That night, however, I served an immature puffball along with a half-mature one for comparison. That's because the standard rule around puffballs has more to do with flavor and correct identification than actual toxicity. There is only one poisoning on record involving a puffball starting to brown, and this case also involved alcohol.1 Granted, we did have a bottle of homemade mead with the meal, but one case including both alcohol and ripening puffballs is not enough to worry about. A greater concern would be whether the puffballs were contaminated.
Growing twenty feet from a fairly major road, these puffballs had been far enough to avoid car fumes. However, they still could have been sprayed. Thinking that some of our symptoms could have been due to herbicide, I threw out the other twenty pounds of puffballs I had collected. After all, two of the guests had similar symptoms, symptoms that don't fit parasol poisoning. One didn't even have any of the parasols, while the one with the more severe symptoms ate more puffballs than anything–and anyone– else. But if the puffballs were contaminated, then why didn't the rest of us who ate them also share (beyond general weakness) similar symptoms? That brings up the next mushroom on the menu, the two-colored bolete.
Boletus bicolor is one of a number of mushrooms that are somewhat edible: they're edible to some people, sometimes. These fickle fungi are known as partials: they're "partial" to certain people, and that list of lucky people can change. Many well-known edibles are actually partials. At least 1-3% of people who eat chicken of the woods, for instance get sick from it. I've gotten sick from the sulfur shelf myself, even though I'd eaten it many times before– and have since. Two other people who also ate it had no problems (lucky for them; there was thirty pounds of it). The chicken mushroom, consequently, is said to be "edible with reservations."
C. molybdites is another example. It frequently causes severe abdominal pain, sometimes even bloody stools, hence the sobering sobriquet, "the gut wrencher." But it doesn't spread its reputation evenhandedly. Reactions like I had, including weakness, chills, and fever are not uncommon. Some people don't get sick at all. In other words, it's "poisonous with exceptions." Nobody knows the extent of its partiality, and there's only one way to find out.
In summary, then, despite the fear that the word "poisonous" or "toxic" elicits– and the false sense of safety that "edible" imparts– there's rarely a clear line between what's poisonous and what isn't. Alcohol, after all, is "more or less" poisonous too. As with mushrooms, this depends on the person, how much they consume, what they consume it with, and many other factors.
When I served the two-colored bolete, I knew that a couple field guides call it a partial; most say it's "edible with caution." The caution is that B. bicolor has a number of look-alikes, several of which are somewhat poisonous. The patch of boletes we found that day, however, all fit the bicolor description well. Besides, in my experience, the supposedly edible and the reputably poisonous species seriously intergrade (i.e., overlap), and I've eaten several collections of mushrooms that "mostly fit" the B. bicolor description without ill effect. I figure that bicolor's apparent partiality is actually due to people occasionally eating the more poisonous varieties.2 However, this would be only the second time I'd served B. bicolor to others, after my girlfriend (always start with those least likely to prosecute).
Serving one B. bicolor to friends is not unreasonable, but serving it with other mushrooms, especially ones they haven't eaten before, is not the best practice. Parceling out your catch of the day into separate meals this can really challenge your selfdiscipline, especially when you only have one or two of each kind to eat. But when it comes down to it, all mushrooms are partials; none are edible by everyone, and "allergic reactions" are common. As I was reminded that night, if something goes wrong, having eaten several mushrooms in one meal can make figuring out what happened that much harder. Hence my own book clearly states, "if you've identified several 'edible' species that you've never had before, pick one to eat; no musmorgasbords." So much for not putting my mushroom where my mouth is!
It's easy to criticize such seemingly reckless consumption in hindsight, and I'll be the first to do it. If you mess up, fess up: it's how we all learn. But keep in mind that I've been using wild mushrooms and plants for food and medicine for fifteen years and gotten sick from it– to my knowledge and recollection– maybe three times (the third time was from roadside lambsquarters served at a potluck). People who eat out or take pharmaceuticals get sick far more often. And the benefits of eating wild food instead of commercial, chemically-laden and even organic food far outweigh the risks.
But tell that to someone who just ate the "gut wrencher." I did have my doubts about the parasols that night– another reason not to have served any other mushrooms. But if I had my doubts, how did they end up in the pan? That's what I'll address in myconfessional, part two.
1 K. Cochran & M. Beug, NAMA toxicology chairpersons, personal communications, 12/15/99 & 11/1/06.
2 this may also be true of the parasol mushroom, another known partial (see part two of this article).