Coprinopsis atramentaria
Taxon 50(1): 235. 2001.
Common Name: Inky Cap
Synonym: Coprinus atramentarius (Bull.: Fr.) Fries
Cap 3-8 cm broad, oval, becoming conic, finally campanulate in age; grey-brown, dry, with innate silky fibrils; disc darker, usually with small flattened scales; margin striate to corrugated, deliquescing towards the center; flesh thin, pallid.
Gills crowded, free, white, becoming pinkish-grey, blackening in age.
Stipe 6-15 cm long, 1-2 cm thick, white above, greyish-brown below the ring, dry, hollow, equal to sometimes enlarged at the base; veil fibrillose, forming an evanescent, basal annulus.
Spores 7-11 x 4-6 µm, elliptical, smooth, with an apical germ pore. Spore print black.
Solitary to clustered, in grass, often near rotting wood; fruiting from fall to spring, although specimens can be collected any month of the year that moisture is available.
Edible, but not recommended unless alcoholic beverages are avoided for several days before and after ingestion. It contains a compound, coprine, that can cause nausea, facial flushing, and an accelerated heart beat when ingested with alcohol.
Coprinopsis atramentaria is recognized by its smooth to silky, greyish-brown caps, clustered habit, and deliquescing gills. It prefers disturbed habitats and thus is at home in the urban environment where it inhabits dirt parking lots, gardens, and grassy areas. Like its cousin, Coprinellus micaceus, it often fruits near buried wood. Coprinopsis atramentaria can be easily distinguished from Coprinus comatus which has a columnar-shaped, scaly cap, and from C. micaceus which a yellow-brown mica-flecked cap and is a smaller mushroom.
Ammirati, J.F., Traquair, J.A. & Horgen, P.A. (1985). Poisonous Mushrooms of the Northern United States and Canada. University of Minnesota Press: Minneapolis, MN. 396 p.
Arora, D. (1986). Mushrooms Demystified. Ten Speed Press: Berkeley, CA. 959 p.
Breitenbach, J. & Kränzlin, F. (1995). Fungi of Switzerland. Volume 4: Agarics (2nd Part). Entolomataceae, Pluteaceae, Amanitaceae, Agaricaceae, Coprinaceae, Strophariaceae. Verlag Mykologia: Luzern, Switzerland. 368 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Knudsen, H. & Vesterholt, J. ed. (2008). Funga Nordica: Agaricoid, boletoid and cyphelloid genera. 965 p.
Lindsey, J.P. & Gilbertson, R.L. (1978). Basidiomycetes that Decay Aspen in North America. J. Cramer: Vaduz. 406 p.
Mitchel, D.H. & Smith, A.H. (1978). Notes on Colorado Fungi III: New and Interesting Mushrooms from the Aspen Zone. Mycologia 70(5): 1040-1063.
Murrill, W.A. (1909). Illustrations of Fungi: II. Mycologia 1(2): 37-40.
Orton, P.D. & Watling, R. (1979). British Fungus Flora: Agarics and Boleti. Vol 2. Coprinaceae: Coprinus. Royal Botanic Garden: Edinburgh, Scotland. 149 p.
Noordeloos, M.E., Kuyper, T.W. & Vellinga, E.C. (2005). Flora Agaricina Neerlandica — Critical monographs on the families of agarics and boleti occurring in the Netherlands. Volume 6. Coprinaceae & Bolbitiaceae. Taylor & Francis: Boca Raton, FL. 227 p.
Redhead, S.A., Vilgalys, R., Moncalvo, J.-M. , Johnson, J. & Hopple Jr., J.S. (2001). Coprinus Pers. and the disposition of Coprinus species sensu lato. Taxon 50: 203-241.
Siegel, N. & Schwarz, C. (2016). Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
Smith, A.H. (1949). Mushrooms in their Natural Habitats. Sawyer's Inc: Portland, OR. 626 p. (PDF)
Van de Bogart, F. (1979). The genus Coprinus in western North America, Part III: Section Atramentarii. Mycotaxon 10(1): 155-174. (PDF)
