Agaricus campestris

Cap	3 to 10 cm in diameter, the cap is creamy white, sometimes developing small scales as it matures. Usually the margin remains down-turned or slightly in-rolled even when the cap has expanded fully. The thick flesh is white, sometimes turning slightly pink when cut but never staining yellow.
Gills	Deep pink at first, the free crowded gills turn dark brown and eventually almost black as the fruit body matures. Old specimens may become infested by maggots, which enter the cap flesh via the gills. Careful inspection is necessary, and it is inadvisable to include very old specimens in collections intended for food.
Stipe	3 to 10 cm tall and 1 to 2 cm in diameter, the white stem is smooth above the single, delicate ring and somewhat scaly below. It is more or less parallel and does not turn yellow when cut. The ring itself is ephemeral, and by the time the fruit body is fully developed there is rarely much evidence of a ring remaining.
Spore print	Deep chocolate brown.
Odour/taste	Not distinctive.
Habitat	On soil among grass in pastures, playing fields and parks.
Season	June to October.
Occurrence	Frequent
Similar species	Agaricus bitorquis, the Pavement Mushroom, is very similar but with a thin double ring; it favours dry places beside paths.