Fungus Fact Friday

Tagged: asco

fungi in the phylum Ascomycota

1

Fungus Fact

#019: Apiosporina morbosa, Black Knot

And now for something completely different: how to recognize different types of trees from quite a long way away.*  Black Cherry (Prunus serotina) is the easiest tree in eastern North America to identify, thanks to the fungus Apiosporina morbosa, commonly known as Black Knot.  Most Black Cherry trees are infected with A. morbosa, which causes dark swellings on branches and trunks.  Older tree trunks are often marred by large swellings caused by A. morbosa that are up to twice the size of the trunk.  These “knots” are easy to spot from a distance (especially in winter), so take advantage of this and amaze your friends by pointing out Black Cherry trees without relying on bark, leaves, or other details!  On twigs and smaller branches, Black Knot makes the branches lumpy and thickened in places, looking remarkably like “dried cat poop on a stick” (thank Michael Kuo for that apt analogy).

Gyromitra brunnea 0

Fungus Fact

#232: Gyromitra brunnea

Gyromitra brunnea is a false morel (see FFF#034) that is fairly common in the eastern and midwestern parts of North America. Like the other false morels, it has a solid to chambered stipe and a wrinkly head. The thing that sets G. brunnea apart, however, is that the cap is highly lobed and there are white seams along the edges of the lobes. No other false morels feature these seams, making G. brunnea easy to identify.

5

Fungus Fact

#067: Mushroom Morpholgy: Verpas

The genus Verpa contains just a handful of species that are encountered occasionally.  These mushrooms look a lot like morels (FFF#033), but are attached just at the top of the cap and have a stipe filled with cottony material.  The cap of a verpa hangs down around the stipe, rather like a thimble on top of a finger.  This arrangement has led to the common names “Thimble Cap” or “Thimble Fungus,” although I usually just call them “verpas.”  Verpas tend to appear just before morels, so if you find one you should come back to check for morels after a week or two.

Elm Bark Beetle galleries 0

Fungus Fact

#228: Dutch Elm Disease

Elm trees were once the defining tree of American life, widely planted in cities, suburbs, and farms.  This changed beginning in the early 1900’s when Dutch Elm Disease arrived on the continent.  Caused by the fungi Ophiostoma ulmi and O. novo-ulmi, Dutch Elm Disease blocks off the water transportation tissues in elm trees, leading to wilting and death.  The fungus moves between trees by using elm bark beetles as vectors and by growing from tree to tree, making it a difficult pathogen to control.  The best way to manage Dutch Elm Disease today is by planting resistant cultivars – fortunately, there are many resistant options available.

Morchella angusticeps 2

Fungus Fact

#140: Morchella angusticeps, the Black Morel of Eastern North America

Black morels can be distinguished from yellow morels by their dark ridges and light pits. Other morels have light ridges with darker (or only slightly darker) pits.  Morchella angusticeps is the most widespread black morel in North America.  It can be found almost anywhere east of the Rocky Mountains, although it is not as common as yellow morels (see FFF#086 and FFF#226).  There are a handful of black morel species, but you can easily identify M. angusticeps because it is the only one in eastern North America that does not grow in burn sites or on wood.

1

Fungus Fact

#226: Tulip Morels

Eastern North America has two general forms of yellow morels: large and small.  Large morels (see FFF#086) typically grow up to 22cm when fully grown, whereas the smaller versions grow up to only 12.5cm tall.  But size isn’t the only difference; the smaller yellow morels tend to be thinner in relation to their height and have long vertical pits.  The larger morels typically look stouter and have more random pits.  Small morels are commonly known as “Tulip Morels” because of their association with tulip trees.  Tulip morels comprise two species that are nearly indistinguishable: Morchella diminutiva and M. sceptriformis.

cryphonectria parasitica on wood 1

Fungus Fact

#222: Cryphonectria parasitica, Chestnut Blight

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.

Camarops petersii 0

Fungus Fact

#215: Camarops petersii, The Dog’s Nose Fungus

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.

Galiella rufa 1

Fungus Fact

#212: Galiella rufa, The Peanut Butter Cup Fungus

Galiella rufa is easy to identify, which is unusual for a cup fungus. Its combination of light brown upper surface, dark brown lower surface, and gelatinous flesh make it instantly recognizable. Officially, the fungus’ common name is the “Hairy Rubber Cup.” This makes sense: its outer surface is covered with tiny hairs and the mushroom has a rubbery texture when you squeeze it. However, the name is kind of gross. I much prefer Michael Kuo’s idea of calling it the “Peanut Butter Cup Fungus,” after the disc-shaped chocolate and peanut butter snacks. The mushroom’s outer surface is chocolatey brown while the upper surface is peanut buttery brown. Additionally, both the snack and the fungus have a soft texture and tooth-like ridges around the upper surface. Unfortunately, the Peanut Butter Cup Fungus is inedible; the only peanut butter cups you should eat are the candies you buy from a store.

Morchella punctipes 5

Fungus Fact

#211: Half-Free Morels

Some parts of the United States have been enjoying morel season for weeks now, but it’s just getting started here in the Mid-Atlantic states. Last weekend (on Earth Day, in fact), there were very few fresh mushrooms and the majority of those were the Half-Free Morel. Half-Free Morels tend to be the first morels to appear, so morel season seems to be proceeding normally (if a bit late) despite the erratic weather in March. Although I’d never found the Half-Free Morel before, it was instantly recognizable. Like the other true morels, it has a ridged and pitted cap as well as a hollow stipe. Unlike the other true morels, only half of the cap attaches to the stipe and the bottom half of the cap hangs down over the stipe. This distinctive morphology gives the mushroom its common name, the “Half-Free Morel.”