''Agaricus bisporus'' is an

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from "eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

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 ...

native to

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

s in

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and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. It has two color states while immature – white and brown – both of which have various names, with additional names for the mature state. ''A. bisporus'' is cultivated in more than seventy countries and is one of the most commonly and widely consumed mushrooms in the world.

Names

When immature and , this mushroom may be known as: * common mushroom * white mushroom * button mushroom * cultivated mushroom * table mushroom * champignon (

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

for mushroom) When immature and , it may be known variously as: * Swiss brown mushroom * Roman brown mushroom * Italian brown mushroom * cremini/crimini mushroom * chestnut mushroom (not to be confused with ''

Pholiota adiposa ''Pholiota adiposa'' is a species of fungus in the family Strophariaceae commonly known as the chestnut mushroom. It was originally described by German naturalist August Batsch in 1786 as a species of '' Agaricus''. Paul Kummer transferred it t ...

'') * baby bella When marketed in its mature state, the mushroom is brown with a cap measuring . This form is commonly sold under the names portobello, portabella, or portobella; the etymology is disputed.

Taxonomy

The common mushroom has a complicated

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

history. It was first described by English botanist Mordecai Cubitt Cooke in his 1871 ''Handbook of British Fungi'', as a variety (var. ''hortensis'') of ''

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 ...

''.

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish ance ...

mycologist Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...

Jakob Emanuel Lange Jakob Emanuel Lange (2 April 1864 – 27 December 1941), was a Danish mycologist who studied the systematics of gilled mushrooms. His best-known work is ''Flora Agaricina Danica'', a five-volume plate work on the Agaricales of Denmark. He was als ...

later reviewed a

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

specimen, and dubbed it ''Psalliota hortensis'' var. ''bispora'' in 1926. In 1938, it was promoted to

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

status and renamed ''Psalliota bispora''. Emil Imbach (1897–1970) imparted the current scientific name of the species, ''Agaricus bisporus'' after the genus ''Psalliota'' was renamed to ''Agaricus'' in 1946. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''bispora'' distinguishes the two-spored basidia from four-spored varieties.

Description

The pileus or cap of the original wild species is a pale grey-brown, with broad, flat scales on a paler background and fading toward the margins. It is first hemispherical before flattening out with maturity, and in diameter. The narrow, crowded gills are free and initially pink, then red-brown, and finally a dark brown with a whitish edge from the cheilocystidia. The cylindrical stipe is up to tall by wide and bears a thick and narrow

ring Ring may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell :(hence) to initiate a telephone connection Arts, entertainment and media Film and ...

, which may be streaked on the upper side. The firm flesh is white, although it stains a pale pinkish-red on bruising. The spore print is dark brown. The spores are oval to round and measure approximately 4.5–5.5 μm × 5–7.5 μm, and the basidia usually two-spored, although two- tetrasporic varieties have been described from the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in ...

and the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

, with predominantly heterothallic and homothallic lifestyles, respectively. This mushroom is commonly found worldwide in fields and grassy areas following rain, from late spring to autumn, especially in association with manure. It is widely collected and eaten in many parts of the world; however, it resembles deadly or poisonous lookalikes (see below).

Lookalike species

The common mushroom could be confused with young specimens of the deadly poisonous destroying angel (''Amanita'' sp.), but the latter may be distinguished by their volva or cup at the base of the mushroom and pure white gills (as opposed to pinkish or brown of ''A. bisporus''). A more common and less dangerous mistake is to confuse ''A. bisporus'' with '' Agaricus xanthodermus'', an inedible mushroom found worldwide in grassy areas. ''A. xanthodermus'' has an odor reminiscent of

phenol Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...

; its flesh turns yellow when bruised. This fungus causes

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

and vomiting in some people. The poisonous European species '' Entoloma sinuatum'' has a passing resemblance but has yellowish gills, turning pink, and lacks a ring.

Cultivation history

The earliest scientific description of the commercial cultivation of ''A. bisporus'' was made by French botanist Joseph Pitton de Tournefort in 1707. French agriculturist

Olivier de Serres Olivier de Serres (; 1539–1619) was a French author and soil scientist whose '' Théâtre d'Agriculture'' (1600) was the accepted textbook of French agriculture in the 17th century. Biography Serres was born in 1539 at Villeneuve-de-Berg, A ...

noted that transplanting mushroom

mycelia Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates in ...

would lead to the propagation of more mushrooms. Originally, cultivation was unreliable as mushroom growers would watch for good flushes of mushrooms in fields before digging up the mycelium and replanting them in beds of composted manure or inoculating 'bricks' of compressed litter,

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...

, and manure. Spawn collected this way contained pathogens, and crops would be infected or not grow. In 1893, sterilized, or pure culture, spawn was discovered and produced by the

Pasteur Institute The Pasteur Institute (french: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccines f ...

in Paris for cultivation on composted horse manure. Modern commercial varieties of the common agaricus mushroom were originally light brown. The white mushroom was discovered in 1925 growing among a bed of brown mushrooms at the Keystone Mushroom Farm in Coatesville,

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. Louis Ferdinand Lambert, the farm's owner and a mycologist by training, brought the white mushroom back to his laboratory. As with the reception of white bread, it was seen as a more attractive food item and became grown and distributed. Similar to the commercial development history of the

navel orange An orange is a fruit of various citrus species in the family Rutaceae (see list of plants known as orange); it primarily refers to ''Citrus'' × ''sinensis'', which is also called sweet orange, to distinguish it from the related ''Citrus × ...

and

Red Delicious Red Delicious is a type of apple with a red exterior and sweet taste that was first recognized in Madison County, Iowa, in 1872. Today, the name ''Red Delicious'' comprises more than 50 cultivars. From 1968 to 2018, it was the most produced cu ...

apple, cultures were grown from the mutant individuals. Most cream-colored store mushrooms marketed today are products of this 1925 chance natural mutation. ''A. bisporus'' is now cultivated in at least seventy countries worldwide. In the U.S., the white button form of ''A. bisporus'' alone accounts for about 90% of mushrooms sold.

Nutritional profile

In a 100-gram serving, raw white mushrooms provide of food energy and are an excellent source (> 19% of the Daily Value, DV) of the B vitamins,

riboflavin Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in ...

niacin Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...

, and pantothenic acid (table). Fresh mushrooms are also a good source (10–19% DV) of the

dietary mineral In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon ...

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

(table). While fresh ''A. bisporus'' only contains 0.2 micrograms (8 IU) of

vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...

as ergocalciferol (vitamin D2), the ergocalciferol content increases substantially after exposure to

UV light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

Gallery

File:Agaricus bisporus Zuchtchampignon2.jpg, White ''Agaricus bisporus'' File:Champignonnière Jodogne grotte Heyoule Eben Bassenge 01.jpg, Brown variety grown in an underground quarry File:Agaricus bisporus (Cup mushroom, doubled).jpg, Two ''Agaricus bisporus'' mushrooms that have fused together File:Portobello mushrooms.jpg, Portobello mushrooms File:Giant mushroom cross-section.jpg, Cross-section of a portobello cultivar File:Giant mushroom underside.jpg, Ventral view of a portobello cultivar with a bisected stipe File:2014 11 Portobello rocket feta toasted baguette.jpg, Grilled portobello,

feta Feta ( el, φέτα, ) is a Greek brined white cheese made from sheep's milk or from a mixture of sheep and goat's milk. It is soft, with small or no holes, a compact touch, few cuts, and no skin. Crumbly with a slightly grainy texture, it is ...

, and

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

salad on toasted baguette