The American Chestnut Tree, Castanea dentata, was once one of the dominant trees in eastern North American forests. It rivalled oak trees in terms of size and abundance. The trees were also highly valued for their rot-resistant wood and edible seeds, making it one of the most economically important trees in eastern North America. So, if the trees were so common and so important, where are they today? The downfall of the American Chestnut began in New York in 1904, when a disease called Chestnut Blight suddenly appeared and swept across the continent. By 1950, the disease had infected and killed almost every American Chestnut. Chestnut Blight is caused by the Asian fungus Cryphonectria parasitica, which grows in the outer wood of the tree and essentially chokes trees to death. The aggressive pathogen has doomed the American Chestnut to extinction, unless humans can come up with a solution.
Fungus Fact Friday
Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of news stories that have taught me something about fungi from mid-May through Early September 2018. Read each summary to learn about: zombie ants, mushroom poisonings, White Nose Syndrome, Bananas, and more.
Aleurodiscus oakesii is an unusual mushroom that grows on living trees but isn’t considered a parasite. The fungus decomposes the outer layer of hardwood tree bark. This doesn’t harm the bark but does cause smooth patches (thus the name “Smooth Patch Disease”). The mushrooms themselves appear occasionally inside these smooth patches. Each mushroom is a small tan roughly circular crust fungus, so some other common names for the fungus include: “Oak Parchment,” “Hop Hornbeam Disc,” and “Oake’s Crust.” These nondescript mushrooms are easier to identify by their ecology than morphology. Additionally, you can always see the smooth patches, but the mushrooms are more elusive. Despite regularly finding smooth patches, it took me four years to find the actual mushrooms.
Amanita rubescens (and its close relatives) could be considered the fugu (pufferfish) of the mushroom world: both are edible but careless mistakes can be deadly. Although A. rubescens is considered edible and many people eat it, most people avoid the mushroom because it is easily confused with some deadly poisonous amanitas. A. rubescens slowly stains pinkish when injured, earning it the nickname “The Blusher.” Other than this distinctive staining reaction, the mushroom looks a lot like other species of Amanita; the Blusher is a tannish umbrella-shaped agaric with warts on the cap and a ring on the stalk.
It’s hard being an insect. Despite being numerous, insects have many predators, have to deal with human pesticides and cars, and are susceptible to dreadful fungal pathogens. Some of these entomopathogenic fungi take control of their hosts’ bodies in innovative but disturbing ways. One such fungus is Massospora cicadina, which infects periodical cicadas (Magicicada spp., which appear in eastern North America every 13 or 17 years). After spending over a decade in the soil waiting for its hosts to emerge, the fungus infects the cicadas and causes their abdomens to pop off. The cicadas then fly around and try to mate with each other, spreading the fungal infection both through the air and through contact. It’s hard to imagine a more horrific sexually transmitted infection, even in the insect world.
Boletes are some of the most beautiful mushrooms; their striking color combinations and distinctive textures make the entire group extremely photogenic. One of my favorite boletes to photograph is Butyriboletus frostii, commonly known as the “Candy Apple Bolete” or “Frost’s Bolete.” This mushroom is bright red with yellow and orange layered underneath and has a prominently reticulated stipe. To capture all the beauty of B. frostii, you need to photograph it when it’s young and its red pores are still covered with golden droplets. You may know this mushroom under a different name; when I first learned this mushroom way back in 2015, it was called Boletus frostii. Then its name changed to Exsudoporus frostii before changing again to Butyriboletus frostii, which is the correct name as of this writing in July 2018.
One of the most unusual things I found in my first year of mushroom hunting was a log covered with a layer of orange fuzz – reminiscent of shag carpeting, which looks out-of-place in a natural setting. After much searching, I discovered that the fuzz was produced by a mushroom: Coprinellus domesticus. The mushroom itself is an inky cap, but the fuzz – called an ozonium – lasts longer and is therefore easier to find. Nobody knows why the fungus makes an ozonium, but it certainly makes identification easier. You might also find this mushroom fruiting in your bathroom. As its species name implies, the fungus routinely appears in wet areas of homes. The mushroom has a few common names that are used occasionally. These include the “Firerug Inkcap” (primarily British), “Retro Inky” (from MushroomExpert.Com), and “Domestic Inkcap” (translated from French).
Neolentinus lepideus is a very tough whitish agaric with lots of scales that appears on dead conifer wood. Its gills have a serrated margin, a characteristic shared with pretty much every species that has “lentin” in its genus name. In the United States N. lepideus is called the “Train Wrecker” because it often appears on railroad ties. In most other parts of the world, the mushroom is simply called the “Scaly Lentinus.”
Scleroderma citrinum is a common earthball that appears in a variety of habitats around the world. The mushroom is one of the most often collected Scleroderma species, so one of its common names (mostly used in Europe) is “The Common Earthball.” S. citrinum has a couple other common names: “The Pigskin Poison Puffball” and the less common “Golden Scleroderma.” Both of these names refer to the mushroom’s outer surface, which is yellow-brown and has a scaly texture reminiscent of a football (American style, often called a “pigskin”). The mushroom’s thick warty outer skin makes it stand out among other earthballs and its interior that quickly turns blackish easily separates it from the true puffballs.
In my area, Ductifera pululahuana is the second most common jelly fungus (after the Wood Ear, FFF#134) that appears in late spring or early summer. It is a strikingly white mushroom that grows in clusters of densely-packed irregular lobes. This shape reminds me of something in between popcorn and fluffy mashed potatoes. Despite this airy appearance, D. pululahuana is rather dense and thick, especially compared to other jelly fungi. I find the ten-syllable scientific name difficult to remember, especially after not using it at all over the winter. When I forget the name, I fall back on the out-of-date name Exidia alba. It’s much easier to remember and refers to the same mushroom, even if it’s incorrect today. The mushroom also goes by the common names “Pale Jelly Roll” and “White Jelly Fungus,” but I’ve never heard those used.
Camarops petersii is one of the more alien-looking things you’ll come across in the woods of eastern North America. It looks like someone had a glob of tar in a paper bag, set the bag down on a log, and ripped away most of the bag leaving the tar sitting on a ripped circle of paper bag. The surface of this mushroom is black, wet, and pimply, reminiscent of a dog’s nose. This similarity has earned it the common name “Dog’s Nose Fungus.” C. petersii is one of the few mushrooms I advise against touching. It’s perfectly safe to touch, but your fingers will get covered in inky black slime. The first time I found this mushroom was a little jarring; its bizarre combination of features (including the fact that it was wet despite having had about a month of no rain) made the fungus look otherworldly.