Fungus Fact Friday

Tagged: poisonous

Fusarium molds 0

Fungus Fact

#205: Zearalenone

Zearalenone is a fascinating mycotoxin produced by Fusarium species. It is the only mycotoxin that mimics the effects of the hormone estrogen. In high doses, it causes sexual organs to develop incorrectly. Pigs are the most susceptible animals and suffer estrogenism and vulvovaginitis when exposed to high levels of zearalenone. The toxin is present in many grain-based foods intended for human consumption, but usually at very low levels. As a result, zearalenone is generally harmless to humans.

Fusarium verticillioides spores 0

Fungus Fact

#204: Fumonisins

Humans have very little to worry about from fumonisins, mycotoxins produced by Fusarium fungi that cause Fusarium ear rot disease of corn (maize). The toxins are linked with esophageal cancer, but scientists cannot prove that they cause cancer. However, fumonisins are a major problem for horses and pigs. In horses, the toxins cause liquefaction of the brain tissue, while in pigs they cause the lungs to fill with water.

Fusarium head blight 1

Fungus Fact

#203: Deoxynivalenol

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.

Aspergillus flavus 3

Fungus Fact

#202: Aflatoxins

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.

Omphalotus illudens 1

Fungus Fact

#007: Omphalotus illudens, The Jack-O-Lantern Mushroom

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 2

Fungus Fact

#196: Hygrophoropsis aurantiaca, The False Chanterelle

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.

Chlorophyllum molybdites 0

Fungus Fact

#181: Chlorophyllum molybdites

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.

Pleurotus ostreatus 3

Fungus Fact

#180: Pleurotoid Mushrooms

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 turns purple under KOH 2

Fungus Fact

#170: Hapalopilus nidulans

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.

#138: Gyromitra esculenta, a False Morel 0

Fungus Fact

#138: Gyromitra esculenta, a False Morel

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).