Agaricus campestris, the field or meadow mushroom, is a white grassland Agaricus that grows singly, in groups or in fairy rings in fields and lawns, rarely in woodland. Young gills are deep pink, turning brown and then dark chocolate brown; the thin ring collapses quickly, and the flesh does not stain yellow. It is not commercially cultivated because it matures quickly and keeps poorly.
Choice edible, but it resembles poisonous species. Destroying angels (Amanita virosa and relatives) have white gills, a white spore print and a volva; A. virosa has been eaten by mistake for it in France. The yellow stainer (A. xanthodermus) bruises yellow and causes gastrointestinal upset; A. californicus and A. hondensis are also poisonous. Lawn specimens may carry pesticides or other chemicals.
Never eat a wild mushroom based on a web page — confirm with an expert.
Mycology is an evolving science: names, classifications and safety information change as research advances. Entries are compiled from cited sources and reviewed, but may be incomplete or out of date — check the sources, and never rely on this library alone to identify or eat a mushroom.
Habitat
Saprobic in meadows, pastures, fields, lawns and other grassy areas, appearing after rain from late summer onward; singly, in groups, or in arcs and fairy rings. Rarely in woodland.
Distribution
Reported from Europe, Asia, North Africa, Australia, New Zealand and North America, including Mexico. In North America the name covers a species complex: east of the Rocky Mountains, sequenced look-alike collections have proved to be other species (e.g., A. andrewii, A. argenteus, A. porphyrocephalus var. pallidus), and western use of the name is provisional.
Characteristics
Cap: 3–12 cm; white; hemispherical becoming convex to nearly flat; bald and silky to finely scaly. Gills: Free, crowded; deep pink when young, then brown, then dark chocolate brown. Stem: 3–10 cm long, 1–2 cm thick; mostly white; more or less equal above a tapering base. Ring: Single, thin, white, collapsing quickly. Flesh: White; unchanging when sliced or bruising dingy reddish brown, never yellow. Odor: Like commercial button mushrooms. Spore print: Dark brown; spores ellipsoid, smooth, thick-walled, about 5.5–8.5 × 4–5 µm; basidia 4-spored.
