Shaggy Manes and Inky Caps: Mushrooms, Uses, and Health Effects

Inky caps are a group of mushrooms that have an unusual method of distributing their spores. Members of the group digest their own cap. The gills are located on the undersurface of the cap and bear the reproductive spores. As autodigestion takes place, the cap and gills change into a black, gooey liquid. The spores aren’t digested, however. They are released in the liquid and exposed to air currents, enabling them to be carried to new areas. The shaggy mane and the common inky cap are North American members of the inky cap group.

All of the mushrooms that produce a black liquid as they mature are referred to as inky caps. Some species are collected for food, although people are careful to eat the mushrooms before they turn to goo. A few species contain a chemical called coprine, which greatly increases the unpleasant effects of alcohol ingestion. Coprine produces similar effects to disulfiram (trade name Antabuse), a medication given to alcoholics to increase their sensitivity to alcohol and encourage abstinence.

One common inky cap mushroom in North America is Coprinus comatus, which is also known as the shaggy mane, shaggy inky cap, and the lawyer’s wig. The shaggy mane has a widespread distribution and is found in Europe, Australia, and New Zealand as well as in North America. The mushroom is versatile and appears in bare soil, grass, areas with gravel, and disturbed areas beside roads. It commonly appears in the fall.

Another inky cap in North America is Coprinopsis atramentaria. It’s also known as the common inky cap, tippler’s bane, and the alcohol inky. Like the shaggy mane, it’s an edible mushroom. The common inky cap contains coprine, however. Alcohol should be avoided when eating this species. The correct identification of both mushrooms is vital before they are used as food since poisonous mushrooms can be dangerous.

As in all fungi that produce mushrooms, the body of the shaggy mane fungus consists of thread-like structures called hyphae. The branching hyphae form a mass known as a mycelium that is usually hidden in the substrate of the mushroom. The mycelium produces aerial mushrooms to distribute the reproductive spores of the fungus.

Unlike plants, fungi don’t contain chlorophyll and can’t produce their food by photosynthesis. Instead, they secrete digestive enzymes into their food source and then absorb the products of the digestion. Some fungi are more active than others in their effort to get food. Nematophagous fungi immobilize, kill, and digest tiny worms called nematodes that live in the soil. Researchers have discovered that Coprinus comatus is nematophagous.

The young shaggy mane mushroom is elongated and roughly cylindrical in shape. It’s white or cream in colour but generally has a brown tip. The cap is covered by cream or tan scales that are upturned. The scales make the mushroom look somewhat like a traditional lawyer’s wig and give it one of its common names. The gills under the cap are white at first but gradually turn grey and then black. A ring of tissue called an annulus surrounds the stem of the mushroom.

The mushroom doesn’t open to form the typical umbrella shape of grocery store mushrooms until it begins autodigestion, turning black as it does so. It begins to digest itself in as little as twenty-four hours after its first appearance. Enzymes called chitinases break down the chitin providing strength to the cell walls in the gills and cap, which destroys the cells in these areas.

Autodigestion begins at the edge of the cap and proceeds inwards. The cap opens and the edge curls upward as digestion takes place, exposing successive layers of spores to air currents. The gills are tightly packed, so their digestion helps to free the spores. In some inky cap mushrooms deliquescence or liquefaction of the cap is complete, while in others it’s only partial.

In 1820, English poet Percy Bysshe Shelley wrote the four lines below in his poem “The Sensitive Plant”. The lines appear just after a stanza about other fungi and are commonly believed to be a description of a shaggy mane mushroom undergoing autodigestion. According to the University of Adelaide, the lines were omitted from later versions of the poem.

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.

Despite its strange behaviour, the shaggy mane is edible and is said to be pleasantly flavoured. Collecting wild mushrooms to eat can be dangerous, since many are poisonous. A mistake in identification can be deadly. Mushroom experts say that the shaggy mane has a distinctive appearance and is easily identified, however. It would be a good idea to check with an experienced mushroom forager before picking and eating shaggy manes for the first time, though.

The mushrooms should be collected from an unpolluted area while they are still in excellent condition. They will start turning into ink just a few hours after being picked. Refrigeration slows this process down only slightly. The ink isn’t dangerous to eat, but it doesn’t taste very good. Some mushrooms should be left unpicked so that they can release their spores into the environment and reproduce.

The common inky cap mushroom is bell shaped and has a striated surface on its cap. The cap is light grey or buff in color and has a ragged or pleated edge. As in the shaggy mane, the gills are white at first and then to turn to grey and finally to black. Also as in the shaggy mane, the cap doesn’t open up into an umbrella shape until autodigestion begins.

The common inky cap is found in North America, Europe, and other parts of the world. It’s not as distinctive or as easily identified as the shaggy mane, until it turns to ink. The mushroom appears in the fall and grows in soil and grassy areas, in areas where wood is decaying, and on disturbed land. Like the shaggy mane, the common inky cap has been known to push through asphalt as it grows.

The mushroom is edible, but unlike the shaggy mane it contains coprine. The alternate names of tippler’s bane and alcohol inky are certainly appropriate for this fungus. Consuming alcohol before or after eating common inky caps produces very unpleasant effects.

Coprine is considered to be a mycotoxin—a toxin that comes from a fungus. The combination of common inky caps and alcohol produces unpleasant symptoms but doesn’t seem to be dangerous. Recovery is apparently complete, although it’s possible that secondary effects could be serious. There has been at least one report of an esophageal rupture due to excessive vomiting after consuming common inky caps and alcohol.

Symptoms of coprine toxicity include:

  • flushed skin and a warm sensation
  • rapid heartbeat and palpitations
  • a tingling sensation in the arms and legs
  • a metallic taste in the mouth
  • nausea
  • vomiting

If symptoms are severe or last for a long time, medical aid should be sought. It’s also important to note that the symptoms listed above can have other causes besides mushroom poisoning.

Coprine produces its effects on alcohol metabolism if the alcohol is consumed after common inky caps are eaten. There are reports that the effects can appear if alcohol is drunk up to five days after eating the mushrooms. Coprine may also affect the body if ingested shortly before alcohol consumption. Ingestion of coprine without alcohol seems to be safe, however.

In normal alcohol metabolism, the body converts the alcohol to acetaldehyde. Acetaldehyde is responsible for most of the symptoms of a hangover. An enzyme called acetaldehyde dehydrogenase converts the acetaldehyde to relatively harmless acetate and carbon dioxide. Coprine stops acetaldehyde breakdown, thereby intensifying and prolonging the effects of alcohol ingestion.

Disulfiram is a chemical given to alcoholics to deliberately increase the unpleasant symptoms of alcohol consumption. The strategy is designed to encourage the reluctance to drink alcohol. At one time it was thought that coprine might be a good substitute for disulfiram in treating alcoholism. However, this idea was given up when an experiment with dogs showed that coprine damaged reproductive organs and caused sterility in males. The coprine needed to be ingested in large amounts to cause these effects, however.

Dusulfiram is marketed with the trade name of Antabuse or Antabus. It has a different chemical structure from coprine, but like coprine it prevents acetaldehyde breakdown in the liver by inhibiting the acetaldehyde dehydrogenase enzyme. This increases a person’s sensitivity to the negative effects of alcohol consumption.

Inky caps are a fascinating part of nature. Observing and photographing them is an enjoyable part of my autumn walks. I don’t collect wild mushrooms for food, though. If you want to collect them, you should seek advice from an experienced forager. In addition, you should read more than one mushroom identification book and look at lots of photos and videos in order to pick up further identification clues.

It’s important to collect only distinctive species of mushrooms that aren’t easily confused with poisonous ones. Many dangerous mushrooms can be mistaken for edible ones. Collectors need to be cautious when gathering any type of fungus, especially when they don’t have access to the specialized equipment and techniques used by scientists for identification.

I’m content to admire and photograph wild mushrooms and to get my edible ones from the grocery store. My local stores sell quite a wide variety of mushroom species, which satisfies my desire for different tastes.

  • Coprinus comatus information from Mykoweb
  • The full version of “The Sensitive Plant” by Percy Bysshe Shelley is shown on the University of Adelaide website. (The omitted verse about the shaggy mane is listed after the “Conclusion” section of the poem under the heading “Cancelled Passage”.)
  • Facts about Coprinopsis atramentaria from Mykoweb
  • Information about coprine toxicity in an abstract from the Medscape website (The abstract places the common inky cap in the genus Coprinus, but it’s currently classified in the genus Coprinopsis.)