''Agaricus bisporus'', commonly known as the cultivated mushroom, is a basidiomycete mushroom native to grasslands in Eurasia and North America. It is fungiculture, cultivated in more than 70 countries and is one of the most commonly and widely Edible mushroom, consumed mushrooms in the world. It has two color states while immature – white and brown – both of which have various names, with additional names for the mature state, such as chestnut, portobello, portabellini, button and champignon de Paris. ''A. bisporus'' has some deadly Mushroom poisoning, poisonous lookalikes in the wild.

Description

The Pileus (mycology), 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 measures in diameter. The narrow, crowded Lamella (mycology), gills are free and initially pink, then red-brown, and finally a dark brown with a whitish edge from the cheilocystidia. The cylindrical Stipe (mycology), stipe is up to tall by wide and bears a thick and narrow Annulus (mycology), ring, 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 four-spored varieties have been described from the Mojave Desert and the Mediterranean Sea, Mediterranean, with predominantly heterothallic and homothallic lifestyles, respectively.

Similar species

The common mushroom could be confused with young specimens of a group of Mushroom poisoning, lethal mushrooms in the ''Amanita'' genus referred to as destroying angels, but the latter may be distinguished by their Volva (mycology), 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 ''Agaricus bisporus'' with ''Agaricus xanthodermus, A. xanthodermus'', an inedible mushroom found worldwide in grassy areas. ''A. xanthodermus'' has an odor reminiscent of phenol; its flesh turns yellow when bruised. This fungus causes nausea 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.

Taxonomy

The common mushroom has a complicated Taxonomy (biology), taxonomic history. It was first described by English botanist Mordecai Cubitt Cooke in his 1871 ''Handbook of British Fungi'', as a Variety (botany), variety (var. ''hortensis'') of ''Agaricus campestris''. Danish people, Danish mycologist Jakob Emanuel Lange later reviewed a cultivar specimen, and dubbed it ''Psalliota hortensis'' var. ''bispora'' in 1926. In 1938, it was promoted to species 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 name (botany), specific epithet ''bispora'' distinguishes the two-spored basidia from four-spored Variety (botany), varieties. Portobello mushrooms

Etymology

When immature and , this mushroom may be known as: * common mushroom * white mushroom * button mushroom * cultivated mushroom * table mushroom * champignon (French language, French for mushroom) de Paris When immature and , it may be known variously as: * Swiss brown mushroom * Roman brown mushroom * Italian brown mushroom * cremini (also crimini) mushroom * chestnut mushroom (not to be confused with ''Pholiota adiposa'') * 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.

Distribution and habitat

This mushroom is commonly found worldwide in fields and grassy areas following rain, from late spring to autumn, especially in association with manure.

Cultivation

Production

In 2022, world production of mushrooms (including truffles) was 48 million tonnes, led by China with 94% of the total (table). Japan and the United States were secondary producers.

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 noted that transplanting mushroom mycelia 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, 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 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. 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 and Red Delicious 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 cultivated in at least seventy countries worldwide.

Nutrition

In a 100-gram serving, raw white mushrooms provide of food energy and are an excellent source (20% or more of the Daily Value, DV) of the B vitamins riboflavin, Niacin (nutrient), niacin, and pantothenic acid (table). Fresh mushrooms are also a good source (10–19% DV) of the mineral (nutrient), dietary minerals phosphorus and potassium (table). While fresh ''A. bisporus'' only contains 0.2 micrograms (8 IU) of vitamin D per 100 g, the ergocalciferol (D₂) content increases substantially to 11.2 micrograms (446 IU) after exposure to UV light.

Gallery

File:Giant mushroom underside.jpg, Ventral view of a portobello cultivar with a bisected Stipe (mycology), stipe File:2014 11 Portobello rocket feta toasted baguette.jpg, Grilled portobello, feta, and Eruca sativa, arugula salad on a toasted baguette