Shaggy Mane (Coprinus comatus)

Photograph of mushroom, shaggy mane, amongst the leaves

January 3rd, 2021

By Rachel Floyd

One of the most interesting mushrooms that pops up in fall and early winter in the Piedmont is the shaggy mane (Coprinus comatus).  It is in a group of mushrooms commonly called inky caps, owing to their habit of dissolving into black piles of goo shortly after pushing their caps and stalks above ground.  This process of liquefaction is called autodigestion and it is an unusual but effective way for a Coprinus to expose its reproductive spores to air currents for distribution.

Shiny black puddles of Coprinus spores have been used by humans for writing ink, fabric dye, and as a natural food coloring. Shaggy manes (correctly identified) can be cooked and eaten at any stage, but as with most mushrooms there are many things to consider before you put them in your mouth.  

For instance, the common inky cap (Coprinus atramentarius), also known as “tippler’s bane” looks quite a bit like a shaggy mane. It contains the mycotoxin coprine. Coprine is not inherently dangerous, however if it is consumed with alcohol it can produce some very nasty effects. In normal alcohol metabolism, the body converts the alcohol to acetaldehyde. An enzyme called acetaldehyde dehydrogenase converts the acetaldehyde to relatively harmless acetate and carbon dioxide. Coprine stops acetaldehyde breakdown, leading to the mother of all hangovers, complete with prolonged bouts of nausea, vomiting, sweating, diarrhea, palpitations, and tingling.

Also consider Chlorophyllum molybdites, commonly called the false parasol or, more colorfully, the vomiter. It can and has been mistaken for a shaggy mane and indeed is the most commonly consumed poisonous mushroom in North America. Luckily, it won’t kill you but it will produce some fairly severe gastrointestinal distress. 

I am tempted to think that one of the reasons that we humans enjoy eating wild mushrooms is due to the thrill of knowing the risks that they pose. Indeed, humans like to eat all kinds of strange things, but what do shaggy mane mushrooms like to eat? As with all fungi that produce fruiting structures that we call mushrooms, the true body of the shaggy mane fungus consists of thread-like structures called hyphae. The hyphae form a mass known as a mycelium that is usually concealed underground. Besides munching on decaying plant matter, shaggy mane mycelium has also been shown to excrete chemicals and enzymes that kill, and digest tiny worms called nematodes that live in the soil. Officially that makes them nematophagous (nematode eaters), but I think that it could be argued that this strange appetite renders them carnivores! 

Unfortunately, I can find no written record of their past or current use by the indigenous people of what is now called North America, but a Coprinus species seems to have caught the eye and lodged in the imagination of English poet Percy Blythe Shelley. The following (rather ominous) lines were published within a poem titled “The Sensitive Plant” in 1899. 

Their mass rotted off them flake by flake,

Till the thick stalk stuck like a murderer’s stake,

Where rags of loose flesh yet tremble on high, 

Infecting the winds that wander by.