Agaricus | |
---|---|
The type species Agaricus campestris (field or meadow mushroom) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Basidiomycota |
Class: | Agaricomycetes |
Order: | Agaricales |
Family: | Agaricaceae |
Genus: | Agaricus L. (1753) |
Type species | |
Agaricus campestris L. (1753) | |
Synonyms [1] | |
Agaricus is a genus of mushroom-forming fungi containing both edible and poisonous species, with over 400 members worldwide [2] [3] and possibly again as many disputed or newly-discovered species. The genus includes the common ("button") mushroom ( Agaricus bisporus ) and the field mushroom ( A. campestris ), the dominant cultivated mushrooms of the West.
Members of Agaricus are characterized by having a fleshy cap or pileus, from the underside of which grow a number of radiating plates or gills, on which are produced the naked spores. They are distinguished from other members of their family, Agaricaceae, by their chocolate-brown spores. Members of Agaricus also have a stem or stipe, which elevates it above the object on which the mushroom grows, or substrate, and a partial veil, which protects the developing gills and later forms a ring or annulus on the stalk.
Several origins of genus name Agaricus have been proposed. It possibly originates from ancient Sarmatia Europaea, where people Agari, promontory Agarum and a river Agarus were known (all located on the northern shore of Sea of Azov, probably, near modern Berdiansk in Ukraine). [4] [5] [6]
Note also Greek ἀγαρικόν, agarikón, "a sort of tree fungus" (There has been an Agaricon Adans. genus, treated by Donk in Persoonia 1:180.)
For many years, members of the genus Agaricus were given the generic name Psalliota, and this can still be seen in older books on mushrooms. All proposals to conserve Agaricus against Psalliota or vice versa have so far been considered superfluous. [7]
Dok reports Linnaeus' name is devalidated (so the proper author citation apparently is "L. per Fr., 1821") because Agaricus was not linked to Tournefort's name. Linnaeus places both Agaricus Dill. and Amanita Dill. in synonymy, but truly a replacement for Amanita Dill., which would require A. quercinus, not A. campestris be the type. This question is compounded because Fries himself used Agaricus roughly in Linnaeus' sense (which leads to issues with Amanita), and A. campestris was eventually excluded from Agaricus by Karsten and was apparently in Lepiota at the time Donk wrote this, commenting that a type conservation might become necessary. [8]
The alternate name for the genus, Psalliota, derived from the Greek psalion/ψάλιον, "ring", was first published by Fries (1821) as trib. Psalliota. The type is Agaricus campestris (widely accepted, except by Earle, who proposed A. cretaceus). Paul Kummer (not Quélet, who merely excluded Stropharia) was the first to elevate the tribe to a genus. Psalliota was the tribe containing the type of Agaricus, so when separated, it should have caused the rest of the genus to be renamed, but this is not what happened. [9]
The use of phylogenetic analysis to determine evolutionary relationships amongst Agaricus species has increased the understanding of this taxonomically difficult genus, although much work remains to be done to fully delineate infrageneric relationships. Prior to these analyses, the genus Agaricus, as circumscribed by Rolf Singer, was divided into 42 species grouped into five sections based on reactions of mushroom tissue to air or various chemical reagents, as well as subtle differences in mushroom morphology. [10] Restriction fragment length polymorphism analysis demonstrated this classification scheme needed revision. [11]
As of 2018, this genus is divided into 6 subgenera and more than 20 sections: [12] [13] [14]
Subgenus Agaricus
Subgenus Flavoagaricus
Subgenus Minores
Subgenus Minoriopsis
Subgenus Pseudochitonia
Subgenus Spissicaules
The fungal genus Agaricus as late as 2008 was believed to contain about 200 species worldwide [20] but since then, molecular phylogenetic studies have revalidated several disputed species, as well as resolved some species complexes, and aided in discovery and description of a wide range of mostly tropical species that were formerly unknown to science. As of 2020, the genus is believed to contain no fewer than 400 species, and possibly many more.
The medicinal mushroom known in Japan as Echigoshirayukidake (越後白雪茸) was initially also thought to be an Agaricus, either a subspecies of Agaricus "blazei" [21] (i.e. A. subrufescens ), or a new species. [22] It was eventually identified as sclerotium of the crust-forming bark fungus Ceraceomyces tessulatus, which is not particularly closely related to Agaricus.
Several secotioid (puffball-like) fungi have in recent times be recognized as highly aberrant members of 'Agaricus, and are now included here. These typically inhabit deserts where few fungi – and even fewer of the familiar cap-and-stalk mushroom shape – grow. Another desert species, A. zelleri, was erroneously placed in the present genus and is now known as Gyrophragmium californicum]]. In addition, the scientific names Agaricus and – even more so –Psalliota were historically often used as a "wastebasket taxon" for any and all similar mushrooms, regardless of their actual relationships.
Species either confirmed or suspected to belong into this genus include:
A notable group of poisonous Agaricus is the clade around the yellow-staining mushroom, A. xanthodermus . [50]
One species reported from Africa, A. aurantioviolaceus , is reportedly deadly poisonous. [51]
Far more dangerous is the fact that Agaricus, when still young and most valuable for eating, are easily confused with several deadly species of Amanita (in particular the species collectively called "destroying angels", as well as the white form of the appropriately-named "death cap" Amanita phalloides ), as well as some other highly poisonous fungi. An easy way to recognize Amanita is the gills, which remain whitish at all times in that genus. In Agaricus, by contrast, the gills are only initially white, turning dull pink as they mature, and eventually the typical chocolate-brown as the spores are released.
Even so, Agaricus should generally be avoided by inexperienced collectors, since other harmful species are not as easily recognized, and clearly recognizable mature Agaricus are often too soft and maggot-infested for eating. When collecting Agaricus for food, it is important to identify every individual specimen with certainty, since one Amanita fungus of the most poisonous species is sufficient to kill an adult human – even the shed spores of a discarded specimen are suspected to cause life-threatening poisoning. Confusing poisonous Amanita with an edible Agaricus is the most frequent cause of fatal mushroom poisonings world-wide.
Reacting to some distributors marketing dried agaricus or agaricus extract to cancer patients, it has been identified by the U.S. Food and Drug Administration as a "fake cancer 'cure'". [52] The species most often sold as such quack cures is A. subrufescens, which is often referred to by the erroneous name "Agaricus Blazei" and advertised by fanciful trade names such as "God's mushroom" or "mushroom of life", but can cause allergic reactions and even liver damage if consumed in excessive amounts. [53]
The genus contains the most widely consumed and best-known mushroom today, A. bisporus , with A. arvensis , A. campestris and A. subrufescens also being well-known and highly regarded. A. porphyrocephalus is a choice edible when young, [44] and many others are edible as well, namely members of sections Agaricus, Arvense, Duploannulatae and Sanguinolenti. [12] [54]
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. The genus is responsible for approximately 95% of fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin present in these mushrooms is α-Amanitin.
Agaricus bisporus, commonly known as the cultivated mushroom, is a basidiomycete mushroom native to grasslands in Eurasia and North America. It is cultivated in more than 70 countries and is one of the most commonly and widely 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.
Agaricus subrufescens is a species of mushroom, commonly known as almond mushroom, almond agaricus, mushroom of the sun, God's mushroom, mushroom of life, royal sun agaricus, jisongrong, or himematsutake. A. subrufescens is edible, with a somewhat sweet taste and a fragrance of almonds.
The blusher is the common name for several closely related species of the genus Amanita. A. rubescens, or the blushing amanita, is found in Europe and eastern North America, and A. novinupta, also known as the new bride blushing amanita, is found in western North America. Both their scientific and common names are derived from the propensity of their flesh to turn pink upon bruising or cutting.
Tricholoma argyraceum is a grey-capped mushroom of the large genus Tricholoma. It has been often confused with the similar-looking Tricholoma scalpturatum.
Agaricus campestris is a widely eaten gilled mushroom closely related to the cultivated A. bisporus. A. campestris is commonly known as the field mushroom or, in North America, meadow mushroom.
Amanita ocreata, commonly known as the death angel, destroying angel, angel of death or more precisely western North American destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. The large fruiting bodies generally appear in spring; the cap may be white or ochre and often develops a brownish centre, while the stipe, ring, gill and volva are all white. A. ocreata resembles several edible species commonly consumed by humans, increasing the risk of accidental poisoning. Mature fruiting bodies can be confused with the edible A. velosa, A. lanei or Volvopluteus gloiocephalus, while immature specimens may be difficult to distinguish from edible Agaricus mushrooms or puffballs.
Amanita brunnescens, also known as the brown American star-footed amanita or cleft-footed amanita is a native North American mushroom of the large genus Amanita. It differs from A. phalloides by its fragile volva and tendency to bruise brown.
Agaricus augustus, known commonly as the prince, is a basidiomycete fungus of the genus Agaricus.
Chemical tests in mushroom identification are methods that aid in determining the variety of some fungi. The most useful tests are Melzer's reagent and potassium hydroxide.
Agaricus bernardii, commonly called the salt-loving agaricus, or salty mushroom, is an agaric fungus in the family Agaricaceae. The mushroom's thick stem is usually shorter than the diameter of the cap, which ranges from 5–15 centimetres and is convex to flattened. The cap surface is whitish to buff, and can develop scales or warts in age. The gills are initially pink before turning brown when the spores mature. The flesh turns reddish when it is cut or bruised. It resembles species such as A. bitorquis.
Agaricus abruptibulbus is a species of mushroom in the genus Agaricus. It is commonly known as the abruptly-bulbous agaricus or the flat-bulb mushroom. First described by the mycologist Charles Horton Peck, this bulbous-stemmed edible species smells slightly of anise or bitter almond, and turns yellow when bruised or cut. The mushroom is medium-sized, with a white, yellow-staining cap on a slender stipe that has a wide, flat bulb on the base.
Agaricus semotus is a woodland mushroom of the fungus order Agaricales. Like many of its relatives, it can be found spread throughout wooded, moist areas in the southern United States, and has been found in areas ranging from California to Florida. It is also indigenous to Great Britain and Europe. A. semotus has also been collected in New Zealand. Although various authors disagree about its edibility, its modest size prevents it from being a significant source of nutrition.
Agaricus lilaceps, also known as the cypress agaricus or the giant cypress agaricus is a species of mushroom. It is among the largest and most choice edible Agaricus species in California. Aside from size, Agaricus lilaceps is characterized by a robust stature, as the stipe often club-shaped.
Agaricus placomyces is a toxic basidiomycete fungus of the genus Agaricus. It is found in North America; the Eurasian populations formerly known by the same scientific name are nowadays known as A. moelleri, while the present species may also be referred to as A. praeclaresquamosus.
Amanita ravenelii, commonly known as the pinecone lepidella, is a species of fungus in the family Amanitaceae. The whitish fruit bodies are medium to large, with caps up to 17 centimetres wide, and stems up to 25 cm (10 in) long. The cap surface has large warts and the stem has a scaly, bulbous base. The mushrooms have a unique chlorine like odor.
Agaricus hondensis, commonly known as the felt-ringed agaricus, is a species of fungus in the family Agaricaceae. The species was officially described in 1912 by mycologist William Alphonso Murrill, along with three other Agaricus species that have since been placed in synonymy with A. hondensis. Found in the Pacific Northwest region of North America, A. hondensis fruits in the fall under conifers or in mixed forests.
Inocybe godeyi is a species of Inocybaceae fungus found in Europe. The species produces mushrooms with cone-shaped caps up to 5 cm (2 in) in diameter. The caps are cream, becoming browner, but they bruise red. The stem is up to 6 cm (2 in) long, and has a "bulb" at the base. The white flesh has a strong smell and an acrid taste. The mushrooms can be found on forest floors in autumn months; the species forms an ectomycorrhizal relationship to surrounding trees, favouring beech. I. godeyi is known to be poisonous, containing muscarine compounds, and consumption of the mushrooms can lead to SLUDGE syndrome. The species is sometimes mistaken for the deadly I. erubescens.
Agaricus brunneofibrillosus, commonly known as the dusky mushroom or bleeding agaricus, is a mushroom in the family Agaricaceae. It has a medium to dark brown cap up to 6 cm (2.4 in) in diameter with brownish fibrillose scales that darken in age. The tightly-packed gills are initially cream colored before becoming pinkish, lilac-gray, and finally brownish as the spores mature. The stout stem is enlarged to bulbous at the base which has one or more brown bands, and a white, membranous ring. The mushroom is edible, and has a pleasant odor similar to button mushrooms, and tastes similar to Agaricus bisporus when cooked.
Amanita ananiceps is a species of agaric fungus in the family Amanitaceae native to Australia.