Inky Cap – Coprinoid mushrooms

Coprinus comatus shaggy mane Pyrenees 1509110
The Shaggy Mane is the most well known of the inky caps, and one of the few that remains in the genus Coprinus

Common Name:  Shaggy Mane, lawyer’s  wig, inky cap  – The unusual bullet shape of the cap bears some resemblance to the pate so that the cascading scales become disheveled locks or shaggy mane.

Scientific Name: Coprinus comatus – The generic name is from the Greek koprinos, meaning “of dung,” as many of its constituent fungi grow on animal feces. Comatus is Latin for “hairy,” referring to the texture of the cap. Family: Coprinaceae (now Agaricaceae)

Potpourri:  The Coprinaceae was widely known as the inky cap family for the notable and unique characteristic behavior of some of the larger species like the shaggy mane. Rather than open out into the umbrella shape of a typical mushroom for the air-borne dispersal of spores, the inky caps slowly dissolve into a black, gelatinous fluid that oozes slowly to the ground below. The gradual decomposition of  plant and mushroom tissues into a gooey mass is called deliquescence, a specialized case of decomposition. This term is sometimes applied to the inky caps but it is somewhat of a misnomer. Stinkhorns also prematurely degrade to a syrupy liquid that is redolent ― the aroma attracts insects that crawl through the muck and then fly away, dispersing the spores as they go.   The inky cap or  coprinoid mushrooms have a similar purpose absent the smell and the flies. The cap dissolves from the bottom up so that the gills and their attached spores are sequentially uncovered to allow for gradual spore dispersal by air currents. It is considered likely that this is an improvement over the typical mushroom arrangement with spore-bearing gills that extend from the underside of the cap. Once the caps open, the spores, which had been protected during the extension from their hypogeal origination in the mycelium, become exposed to environmental degradation.  The inky cap spores remain covered and thus protected until they are ready for deployment, probably as an evolutionary enhancement to improve survivability. [1]

It is wholly logical  that a peculiar characteristic like cap dissolution into inky black fluid would unite a group of fungi in having a common ancestor. The taxonomic system devised by Carolinus Linnaeus in the eighteenth century relied on such similarities to establish the hierarchical relationships that are still used today; the common traits defined and established family trees with genera of species  below and classes of orders above. Darwin’s observations of these similarities led to his evolutionary theory based on random mutations and survival of the fittest to explain trait radiation from an originator.  All was well with biology until about fifty years ago when the secret life of the genome was slowly but inexorably exposed. As is now well known and institutionalized, biological history is recorded in the arrangement of just four nucleotide bases: adenine A, cytosine C, guanine G, and thymine T (replaced by uracil U when transcribed by RNA). While the complexity of inky cap relationships is far from settled, the inky cap family Coprinaceae is no more. The shaggy mane, C. comatus, which had been the type specimen for the genus Coprinus, is one of the few that remain but it is now in a different family – Agarciaceae. Coprinus is therefore now the inky cap genus in a different family.

Coprinus quadrifidus 3 Scaly Inky Cao Columbia 200529
Scaly inky caps grow in clusters in hardwood debris and mulched areas

The coprinoid mushrooms that have a different DNA profile have been moved to three new genera named Coprinopsis, Coprinellus, and Parasola,  the first two retaining the scatological association of the original. Based on their DNA similarity to the genus Psathyrella they have been included in a newly created family named Psathyrellaceae. [2] The most common example of the newly minted “Coprinus-like” genus is Coprinopsis variegatus (also quadrifidus) , which fortunately goes by the much more mnemonic common name “scaly inky cap.” They appear in large clusters the day after a good soaking rain from decaying hardwood debris, the shaggy domed shapes like a conclave of bewigged nobility or a battery of ballistic missiles. Although they are considered edible, this would only be for the adventuresome, as they are noted for frequently having an unpleasant odor and taste presumably extracted from the substrate debris from which they erupted.

Coprinus micaceous Mica Cap gills AT Rt7 180919
The mica cap has veil fragments on the cap that glisten like mica.

The “little coprinuses” of the new genus Coprinellus are at the opposite end of the larger, maned sporocarps of Coprinus and Coprinus-like fungi of the once majestic inky cap family dining room table. [3] While retaining the deliquescing inkiness of spore dispersal, the bullet shape is absent in most species in favor of a more typical cap and stem mushroom arrangement. The most well known is the mica cap, C. micaceus, which takes its name from the Latin micare meaning “to flash or sparkle.” The silicate mineral mica is a primary constituent of igneous rocks like granite that are characterized by scintillation. Mica caps have evanescent speckles that are the remnants of the partial veil, a barrier employed by some mushrooms to protect the spore-bearing gills on the underside of the cap until the stem is fully extended and the cap opens. They are widely dispersed and quite common on stumps and woody debris and even indoors … David Aurora noted that “bountiful crops sprout periodically from the woodwork of a popular café in Santa Cruz, California.” [4] C. micaceus may be the world’s first scientifically described mushroom, appearing as a woodcut illustration in Rariorum plantarum historia by Carolus Clusius that was published in the early seventeenth century. [5]

Even as it has been removed from the patriarchal position as the quintessence of the inky cap family that is no more, the shaggy mane Coprinus comatus retains it notoriety. It is certainly the inspiration for a stanza on mushrooms in Shelley’s The Sensitive Plant:


Their moss 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 [6]


The importance of inky caps extends to the laboratory and they have accordingly been the subject of numerous foundational fungal research efforts over the years. particularly in the area of sporulation. The formation of the “ink” is due to gill autolysis, the removal of interference for sequential spore ejection in all gilled mushrooms. The spores are held in place by club-shaped structures called basidia that extend outward on both faces of the vertical gill. The inky caps are masters of spores and spore release ― the shaggy mane produces roughly nine thousand million spores in about three days. That works out to 30,000 spores per second.[7]

Dung is a potent source of nutrition for significant swaths of the Kingdom Fungi, the genus name Coprinus is not coincidental. Although feces as food is repugnant to people, coprophagy is standard fare for some fungi, some beetles … one of the scarabs is named dung beetle… and rabbits. For one thing there is a lot of it, deposited daily by roving bands of herbivores leaving cow pies and horse “road apples” in their wake. While most of the proteins are gone, it is replete with cellulose that animals can’t digest but fungi can and nitrogen, a vital element for all things living. Dung can contain up to four percent nitrogen, which is more than the original ingested plant material. There are almost two hundred genera of fungi, mostly ascomycetes or cup fungi, that are primarily coprophagous. One of the more intriguing examples of nature’s insidious exploitation is the zygomycete Pilobolus crystallinus.  Called “the hat thrower,” it is one of several species of fungi that have evolved to grow in dung, shoot their spores up to two meters away toward light, and germinate in the grass away from the dung pile where they are consumed by grazing animals. Passing unaffected through the animal’s digestive system, the spores are deposited in new dung in a new place to perpetuate the cycle. Once the zygomycetes and ascomycetes are done, basidiomycetes like the coprinoid mushrooms take over, a succession based on resources needed for fruiting body formation. [8] Ultimately, the dung is recycled ecologically ― a good thing for otherwise we would be buried in it.

Shaggy manes are one of the more noted edible mushrooms, characterized as “choice” in the more popular mushroom field guides, one of which calls it “an excellent substitute for asparagus, it can also be pickled.” [9] As with all edible fungi, however,  caveats apply and there are  doppelgängers that entice the ill-informed neophyte. In this case, it is the “alcohol inky,” Coprinopsis (nee Coprinusatramentarius that looks more or less like a shaggy mane with a haircut. As mushrooms are somewhat variable in appearance according to age and disposition, one might well mistake this for its cousin C. comatus. This would not be a serious problem since it is also edible unless your gourmet meal of wild mushrooms includes a glass of wine. The problem is that the alcohol inky contains the toxin coprine, which is similar in effect to disulfiram, the chemical used  in drugs administered to enforce alcohol abstinence in those suffering from its addiction. [10] When alcohol is consumed under normal conditions by most people, it is converted to acetaldehyde which is then metabolized to acetate resulting in a pleasant light-headed feeling of mild euphoria. Coprine blocks the metabolic pathway so that acetaldehyde builds up in the body causing “flushing of the face, headache, nausea, vomiting, chest pain, weakness, blurred vision, mental confusion, sweating, choking, breathing difficulty, and anxiety”  known as the disulfiram-ethanol reaction. [11] Eating wild fungi has always been a challenge, but some find it worth the time and trouble. Once the subtleties of identification have been mastered, it is the joy of the hunt that prevails.


  1. Roody, W. Mushrooms of West Virginia and the Central Appalachians, The University of Kentucky Press, Lexington, Kentucky, 2003, pp 268-269
  2. Redhead S. et al. “Coprinus Pers. and the disposition of Coprinus species sensu lato”. Taxon. 1 February 2001 Volume 50 (1) pp 203–241
  3. Volk, T. Coprinus comatus, Fungus of the Month May 2004 available at
  4. Aurora, D. Mushrooms Demystified, Ten Speed Press, Berkeley California, 1986. pp 348-349
  5. Bulliard J.. Herbier de la France [Guide to the Herbs of France] 1786. pp. 241–88, plate 246. See .
  6. Money, N. Mr. Bloomfield’s Orchard, Oxford University Press, New York, 2002. p 17.
  7. Carlile, M., Watkinson, S. and Gooday, G. The Fungi, 2nd edition, Elsevier Academic Press, London, 2006, pp 61-63.
  8. Kendrick, B. The Fifth Kingdom, 3rd edition, Focus Publishing, Newburyport, Massachusetts, 2000. pp 33-34, 184-185.
  9. Lincoff, G. National Audubon Society Field Guide to North American Mushrooms, Alfred A. Knopf, New York, 1981, 99 596-598.
  10. Money, op cit. p 157.