Agaricus bisporus (Lange) Pilát Zuchtchampignon Agaric cultivé, Pratelle, Champignon de Paris Cultivated Mushroom Cap 5–12cm across, hemispherical expanding convex, greyish-brown to umber covered in brown radiating fibres and often slightly scaly with age. Stem 35–55 x 8–14mm, white, often flaky below the membranous sheathing ring. Flesh white bruising faintly red. Taste and smell mushroomy. Gills dirty pinkish darkening with age. Cheilocystidia thin-walled, elongate-clavate, 17–44 x 7–14µ. Spore print brown. Spores ovate to subglobose, 4–7.5 x 4–5.5µ. Basidia two-spored, separating this species from the rest of this genus which all have four-spored basidia. Habitat on manure heaps, garden waste and roadsides, not in grass. Season late spring to autumn. Occasional. Edible. Distribution, America and Europe. This species is believed to be the wild ‘parent’ of many of the cultivated crop varieties, all of which have two-spored basidia.