|Major Groups > Gilled Mushrooms > Dark-Spored > Agaricus > Agaricus campestris|
Agaricus campestris: The Meadow Mushroom
by Michael Kuo
The meadow mushroom, Agaricus campestris, is a beautiful white mushroom that is closely related to the cultivated "button mushrooms" (Agaricus bisporus) sold in North American grocery stores. In most areas it is a fall mushroom and, as its common and Latin names suggest, it comes up in meadows, fields, and grassy areas, after rains. It is recognized by its habitat, its pink gills (covered up by a thin white membrane when the mushroom is young) which become chocolate brown as the mushroom matures, its quickly collapsing white ring, and the fact that it does not discolor yellow when bruised.
Ecology: Saprobic; growing alone, gregariously, or sometimes in fairy rings, in meadows, fields, lawns, and grassy areas; late fall to early winter (occasionally in summer; sometimes year-long in California); widely distributed and common in North America.
Cap: 3-11 cm; convex to broadly convex, occasionally nearly flat; whitish; smooth and glossy to fibrous to nearly wooly or scaly.
Gills: Free from the stem; deep pink becoming brown and then dark chocolate brown in maturity; crowded; covered with a thin white partial veil when in the button stage.
Stem: 2-6 cm long; 1-2.5 cm thick; more or less equal; sometimes tapering slightly to base; with a quickly collapsing white ring; not bruising yellow.
Flesh: Thick and white throughout; not bruising yellow anywhere, even in the base of the stem; very rarely discoloring a pinkish wine color in wet weather.
Odor and Taste: Pleasant.
Chemical Reactions: Cap surface not yellowing with KOH.
Spore Print: Dark chocolate brown.
Microscopic Features: Spores: 5.5-10 x 4-7 µ; elliptical. Cheilocystidia to 10 µ wide. Universal veil hyphae (on cap surface and stem base) without inflated elements.
The North American forms of this mushroom are apparently numerous--and several closely related (identical?) species have been described, including Agaricus andrewii (cheilocystidia 11-18.5 µ wide; universal veil hyphae with inflated elements) and Agaricus solidipes (spores up to 12 µ long; cheilocystidia absent). See also Agaricus porphyrocephalus.
REFERENCES: Linnaeus, 1753. (Fries, 1821; Saccardo, 1887; Kauffman, 1918; Smith, 1949; Smith, 1975; Smith, Smith & Weber, 1979; Weber & Smith, 1985; Arora, 1986; Phillips, 1991/2005; Lincoff, 1992; Metzler & Metzler, 1992; Horn, Kay & Abel, 1993; Evenson, 1997; Barron, 1999; Roody, 2003; McNeil, 2006; Miller & Miller, 2006; Kuo, 2007.) Herb. Kuo 09099401, 09260501, 09290505, 10030504.
Further Online Information:
Cite this page as:
Kuo, M. (2001, September). Agaricus campestris: The meadow mushroom. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/agaricus_campestris.html