Agaricus arvensis Mycological characteristicsgills on hymeniumcap is convexhymenium is freestipe has a ringspore print is brownto blackish-brownecology is saprotrophicedibility: edibleAgaricus arvensis, commonly known as the horse mushroom, is a mushroom of the genus Agaricus.

Taxonomy[edit]

It was described as Agaricus arvensis by Jacob Christian Schaeffer in 1762, and given numerous binomial descriptions since. Its generic name arvensis means 'of the field'.

Description[edit]

The cap is similar to that of Agaricus campestris (the field mushroom). The gills are white at first (when this fungus is most often confused with deadly Amanita genus). They later pass through 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.^[1] It belongs to a group of Agaricus which tend to stain yellow on bruising.

Similar species[edit]

• Agaricus osecanus is rare, and is without the aniseed smell.^[2]
• Agaricus xanthodermus, the yellow stainer, can cause stomach upsets.
• Agaricus silvicola, the wood mushroom, is a touch more arboreal, with a frail and delicate ring, but also edible.
• Agaricus campestris, the field mushroom, is generally (but not always) smaller, has pink gills when young, and is also edible.
• Agaricus bitorquis, the spring agaric(us); looks similar to arvensis and campestris, which are more common in the summer and autumn
• Agaricus bisporus is the more commonly cultivated mushroom of the Agaricus genus.

Distribution and habitat[edit]

It is one of the largest white Agaricus species in Britain (where it appears during the months of July-November), West Asia (Iran)^[3] and North America. Frequently found near stables, as well as in meadows, it may form fairy rings. The mushroom is often found growing with nettles (a plant that also likes nutrient-rich soil). It is sometimes found associated with spruce.^[4]

Conservation[edit]

This mushroom is considered common and widespread, and is not a conservation concern.^[5]

Edibility[edit]

Much prized by farmers and gypsies for generations, the horse mushroom is regarded as 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.^[5]

See also[edit]

• List of Agaricus species

References[edit]

Wikimedia Commons has media related to Agaricus arvensis.