Deoxynivalenol (DON) is a toxin found in grains infected with the fungus Fusarium graminearum and other Fusarium species. It is often called “vomitoxin” because it primarily causes vomiting in humans and livestock. Its long-term effects are mild, but it is still a very important mycotoxin because it is the most common mycotoxin found in food.
mushrooms that contain toxins
Fungi produce innumerable “mycotoxins” – compounds that are toxic to humans. In mushrooms, these cause symptoms ranging from gastrointestinal upset to death (see FFF#091–100 for more). Although these are of significant concern to mushroom hunters, their impact is relatively small. The most significant mycotoxins in terms of the number of people affected are produced by molds that naturally grow on food. Over the next few weeks, I will discuss some of the most problematic food-borne mycotoxins. Topping that list are the aflatoxins, which cause liver cancer and are especially problematic for people in developing nations.
If the spirit of Halloween were a mushroom, it would be Omphalotus illudens. This agaric is commonly known as the “Jack-O-Lantern mushroom” for a few good reasons. First, it is bright orange, like the pumpkins that decorate doorsteps all over the United States in October. Not only is the cap orange, but so are the gills, the stipe, and the interior. Second, the mushroom’s gills glow in the dark, especially when they are young and fresh. Furthermore, the mushroom often has a sweet smell and is poisonous. Nothing says Halloween like something that is orange, glows in the dark, smells sweet, and has a sinister side.
Hygrophoropsis aurantiaca is a bright orange mushroom that appears on rotting wood and forest debris in the summer and fall. It is not a particularly interesting mushroom on its own, but it is worth knowing to make sure you don’t confuse it with other orange mushrooms like golden chanterelles. H. aurantiaca is called the “False Chanterelle” precisely for that reason; if you’re not paying attention, it would be easy to drop one of these into your chanterelle collection.
Happy St. Patrick’s Day! To celebrate, I chose to discuss the Green Spored Lepiota, Chlorophyllum molybdites (I will return to morphological groups of agarics next week). Commonly known as the “Green Spored Lepiota,” the “Green-Gilled Lepiota,” the “False Parasol,” and various derivatives of those names, C. molybdites is the most common culprit in cases of mushroom poisoning in the United States. The large, attractive mushrooms frequently appear in lawns, making them prime candidates for consumption by people who aren’t familiar with mushrooms. Thankfully, the mushroom causes only gastrointestinal (GI) distress. People wishing to avoid this unpleasant experience can easily recognize C. molybdites thanks to its green spores.
Pleurotoid mushrooms are agarics that have a single common feature: they lack a well-developed stipe. Originally, I was not going to include pleurotoid mushrooms as a distinct agaric morphology. Their other physical characteristics vary widely and they belong to multiple unrelated taxonomic groups. To anyone classifying mushrooms, grouping them based on pleurotoid growth is decidedly unhelpful. However, it is a useful group from a field guide standpoint because it quickly reduces the number of possible matches. Eventually, I decided to discuss the pleurotoid mushrooms because they are often mentioned in field guides and because “pleurotoid” is a commonly-used mushroom descriptor.
Hapalopilus nidulans is small, drab, polypore that most people overlook. However, this humble mushroom is remarkable for two reasons: it is poisonous and it produces a lovely purple dye. It is an uncommon mushroom, which reduces the likelihood of someone eating it but also means people working with mushroom dyes never have enough of it. This mushroom appears on decomposing wood in North America and Europe.
This is one of the most common false morels. Anyone hunting morels should be familiar with false morels, since they appear at the same time and are potentially deadly. Gyromitra esculenta can be distinguished from other false morels by its brain-like texture, reddish-brown color, and relatively thin stem. Most people just call esculenta a “false morel,” but it has some other common names, including: “Brain Mushroom,” “Beefsteak Morel,” “Lorchel,” and “Turban Fungus” (the last name is used in Europe).
“Is this mushroom edible?” What a difficult question to answer. The world of edible mushrooms is littered with lookalikes, various degrees of edibility, mushrooms that are edible only under certain conditions, and mushrooms that no one has assessed for edibility. For Hypholoma sublateritium, the question is even more complicated. There is no consensus on whether or not Brick Caps are edible. North American field guides are divided on the issue and European field guides usually list these mushrooms as inedible or poisonous. In my local mushroom club, they are considered edible and are a welcome find in the late fall, when it is usually slim pickings for mushrooms. Because of this ambiguity, community is an essential part of mushroom hunting (despite its culture of secrecy and competition). If you are serious about mushroom hunting, you should be involved with a local mushroom club to ensure that you learn information about...
If you are collecting for the table, this is one little brown mushroom (LBM) that you should definitely be familiar with. Most LBMs go unnoticed because they are heard to spot and are usually too small to consider worth eating. The “Deadly Galerina” is therefore usually not dangerous on its own. The real danger from this mushroom comes when it is accidentally collected along with a group of edible mushrooms. Galerina marginata contains amatoxins, which are also found in such infamous species as Destroying Angels (Amanita virosa complex, FFF#050) and Death Caps (Amanita phalloides, FFF#051). In England, G. marginata goes by the beautifully ominous name, “Funeral Bell.” Unfortunately for me, people in the United States prefer the much blander common name, “Deadly Galerina.”