Agaricus campestris L. ex Fr. syn. Psalliota campestris (L. ex Fr.) Quél. Field Mushroom, Pink Bottom, Agaric champêtre, Rosé de prés, Kerti (mezei) csiperke, Wiesenchampignon, Feldegerling, Prataiolo, prataiolo bianco, Weidechampignon.
Cap 3–10cm across, domed and remaining so a long time before expanding fully, white sometimes creamy yellow, scaly or smooth. Stem 30–100 x 10–15(20)mm, white sometimes yellowing slightly towards the tapered base; ring thin and white, short-lived, often little more than a torn frill. Flesh white, bruising faintly pink especially above the gills. Taste and smell pleasant and mushroomy. Gills deep pink even in unopened ‘buttons’, finally darkening to brown. Cheilocystidia lacking. Spore print brown. Spores ovoid, 7–8 x 4–5µ. Habitat in pastureland. Season late summer to autumn. Frequent. Edible – excellent. Distribution, America and Europe. Comment There are some other, almost identical species best distinguished by their microscopic features: Agaricus andrewii, with large marginal cystidia on the gills (campestris has none), and Agaricus solidipes, with spores up to 10 x 6µ.