Agaricus arvensis

The Horse Mushroom, Agaricus arvensis, is a mushroom of the genus Agaricus.

Taxonomy

Described as Agaricus arvensis by Jacob Christian Schaeffer in 1762, and given numerous binomial descriptions since.(Notably in the 1950's). It's present name arvensis means 'of the field'.

Description

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 species). 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. It belongs to a group of Agaricus which tend to stain yellow on bruising.

Similar Species

• Agaricus osecanus. Which is rare, and is without the aniseed smell.
• Agaricus xanthodermus. (The Yellow Stainer), which can cause stomach upsets.
• Agaricus silvicola. (The Wood Mushroom), which is a touch more arboreal, with a frail and delicate ring, but also edible.
• Agaricus campestris, (The Field Mushroom), which is generally (but not always) smaller, has pink gills when young, and is also edible.

Distribution and Habitat

It is one of the largest white Agaricus species in Britain and North America. Frequently being found near stables, as well as in meadows, where 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.

Edibility

Much prized by farmers and gypsies for generations. The 'Horse Mushroom' is one of the most delicious edible fungi.

References

External links

• Mushroom Expert - Agaricus arvensis
• Mykoweb - Agaricus avernsis