Agrocybe pediades

Agrocybe pediades is a typically lawn and other types of grassland mushroom, but can also grow on mulch containing horse manure. It was first described as "Agaricus pediades" by Swedish mycologist Elias Magnus Fries in 1821, and moved to its current genus "Agrocybe" by Victor Fayod in 1889. A synonym for this mushroom is "Agrocybe semiorbicularis", though some guides list these separately. Technically, it is edible, but it could be confused with poisonous species, including one of the genus "Hebeloma". Some just consider it inedible.
Some experts divide Agrocybe pediades into several species, mainly by habitat and microscopic features, such as spore size. It is recognized by the large, slightly compressed basidiospores with large central germ-spore, 4-spored basidia, subcapitate cheilocystidia and reare development of pleuro cystidia.