Author: Jan Scholten
Synonyme: Psalliota arvensis.
English: Horse mushroom.
German: Weiße Anis-Champignon; Schaf-Egerling; Gemeiner Anis-Egerling; Schaf-Champignon.
Region: Europe, Britain, West Asia, Iran, North America.
Habitat: near stables, in meadows, form fairy rings; often found growing with nettles or spruce; nutrient-rich soil.
Use: edible, much wanted, smelling like anis; much prized by farmers, one of the most delicious edible fungi; although the fruitbodies of this and other yellow-staining Agaricus species often have a build-up of heavy metals, such as cadmium and copper.
Agaricus arvensis showing the so-called) 'cogwheel'.
The cap is similar to that of Agaricus campestris. The gills are white at first, later grey and brown to become dull chocolate. There is a large spreading ring, white above but sometimes with yellowish scales underneath. Viewed from below, on a closed-cap specimen, the twin-layered ring has a well-developed 'cogwheel' pattern around the stipe. This is the lower part of the double ring. The odor is described as like anise. It tends to stain yellow on bruising.