''Agaricus arvensis'', commonly known as the horse mushroom, is a

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

of the genus ''

Agaricus ''Agaricus'' is a genus of mushrooms containing both edible and poisonous species, with over 400 members worldwide and possibly again as many disputed or newly-discovered species. The genus includes the common ("button") mushroom (''Agaricus bisp ...

''.

Taxonomy

It was described as ''Agaricus arvensis'' by

Jacob Christian Schaeffer Jacob (; ; ar, يَعْقُوب, Yaʿqūb; gr, Ἰακώβ, Iakṓb), later given the name Israel, is regarded as a patriarch of the Israelites and is an important figure in Abrahamic religions, such as Judaism, Christianity, and Islam. Ja ...

in 1762, and given numerous binomial descriptions since. Its specific name arvensis means 'of the field'.

Description

The

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

is , whitish, smooth, and dry; it stains yellow, particularly when young. The gills are pale pink to white at first, later passing 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 stalk is long and 1–3 cm wide. The spores are brown and smooth. The odor is described as like

anise Anise (; '), also called aniseed or rarely anix is a flowering plant in the family Apiaceae native to Eurasia. The flavor and aroma of its seeds have similarities with some other spices and herbs, such as star anise, fennel, licorice, and ta ...

. It belongs to a group of ''

'' which tend to stain yellow on bruising.

Similar species

When young, this fungus is often confused with species of the deadly genus ''

Amanita The genus ''Amanita'' contains about 600 species of agarics, including some of the most toxic known mushrooms found worldwide, as well as some well-regarded edible species. This genus is responsible for approximately 95% of the fatalities result ...

''. *''

Agaricus osecanus ''Agaricus'' is a genus of mushrooms containing both edible and poisonous species, with over 400 members worldwide and possibly again as many disputed or newly-discovered species. The genus includes the common ("button") mushroom (''Agaricus bisp ...

'' is rare, and is without the aniseed smell. *''

Agaricus xanthodermus ''Agaricus xanthodermus'', commonly known as the yellow-staining mushroom or simply the yellow-stainer, is a mushroom of the genus ''Agaricus'', which displays a strong yellow colouration at the base of the stem when cut. It is poisonous for mos ...

'', the yellow stainer, can cause stomach upsets. *''

Agaricus silvicola ''Agaricus silvicola'', also known as the wood mushroom, is a species of Agaricus mushroom related to the button mushroom. Taxonomy Originally described as the variety ''Agaricus campestris'' var. ''silvicola'' by Carlo Vittadini in 1832, it w ...

'', the wood mushroom, is a touch more arboreal, with a frail and delicate ring, but also edible. *''

Agaricus campestris ''Agaricus campestris'' is a widely eaten gilled mushroom closely related to the cultivated button mushroom ''Agaricus bisporus''. It is commonly known as the field mushroom or, in North America, meadow mushroom. Taxonomy This species was orig ...

'', the field mushroom, is generally (but not always) smaller, has pink gills when young, and is also edible. *''

Agaricus bitorquis ''Agaricus bitorquis'' is an edible white mushroom of the genus ''Agaricus'', similar to the common button mushroom that is sold commercially. The name supersedes ''Agaricus rodmani''. It is also commonly known as torq, the banded agaric, spring ...

'', the spring agaricus, looks similar to arvensis and campestris, which are more common in the summer and autumn. *''

Agaricus bisporus ''Agaricus bisporus'' is an edible basidiomycete mushroom native to grasslands in Eurasia and North America. It has two color states while immature – white and brown – both of which have various names, with additional names for the mature ...

'' is the most commonly cultivated mushroom of the genus ''Agaricus''.

Distribution and habitat

It is one of the largest white ''Agaricus'' species in Britain (where it appears during the months of July–November), West Asia (Iran) and North America. Frequently found near stables, as well as in meadows, it may form

fairy rings A fairy ring, also known as fairy circle, elf circle, elf ring or pixie ring, is a naturally occurring ring or arc of mushrooms. They are found mainly in forested areas, but also appear in grasslands or rangelands. Fairy rings are detectable by ...

. The mushroom is often found growing with nettles (a plant that also likes nutrient-rich soil). It is sometimes found associated with

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

.Lincoff, Gary. ''The Audubon Society Field Guide to North American Mushrooms''. Chanticleer Press: New York, 1981.

Conservation

This mushroom is considered common and widespread, and is not a conservation concern.

Edibility

This is a choice edible species which has been much prized by farmers for generations, being regarded as one of the most delicious of all edible fungi. Despite this, the fruitbodies of this and other yellow-staining ''Agaricus'' species often have a build-up of

heavy metals upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...

, such as

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

and

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

Gallery

Agaricus arvensis - livadski šampinjon.jpg 2008-08-Agaricus-Stuttgartx7.JPG

References

External links

Mushroom-collecting.com - ''Agaricus arvensis''

{{Taxonbar, from=Q690801 arvensis Edible fungi Fungi of Europe Fungi of North America Fungi described in 1762 Taxa named by Jacob Christian Schäffer