Agaricus abruptibulbus
Encyclopedia
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
, 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
in 1900. In his 1904 Report of the State Botanist publication, he changed the name to Agaricus abruptibulbus. He explained that Elias Magnus Fries
had earlier named a species in the subgenus
Flammula, which he called Agaricus abruptus; the subgenus was later raised to the rank of genus, and the species was given the name Flammula abruptus. Under the transitioning nomenclatural conventions of the time, it was unclear if Agaricus abruptus would remain available for use, so he changed the name.
Agaricus abruptibulbus belongs in the Arvenses clade
of the genus Agaricus (along with species A. silvicola, A. arvensis, and A. semotus
).
Some American authors consider this species to be synonymous with A. silvicola, while some in Europe have synonymized it with the similar species A. essettei. American mycologists Steve Trudell and Joseph Ammirati noted in a 2009 field guide: "The name A. abruptibulbus has been applied to forms with bulbous stipe bases, but variation in stipe shape is so great that the use of this name has been largely abandoned."
is up to 8 cm (3.1 in) in diameter, convex in shape, sometimes with an umbo
, and whitish in color. After being scratched or bruised, the cap turns yellow. The stipe
is 8 – long by 1 – thick and bulbous. A large, white annular ring
is present on the stipe. The gill attachment is free, and the color is initially grayish but turns brownish after the spore
s are developed. Specimens smell slightly of anise
. The spore print
is brown to purple-brown. Spores are elliptical in shape, and are 6–8 by 4–5 µm
. The surface of the cap will stain yellow if a drop of dilute potassium hydroxide
is applied.
is very similar in appearance and also grows in woodlands, but it may be distinguished by the lack of an abruptly bulbous base. Agaricus arvensis
has a more robust stature, lacks the bulbous base, and grows in grassy open areas like meadows and fields. It has larger spores than A. abruptibulbus, typically 7.0–9.2 by 4.4–5.5 µm.
the toxic element cadmium
—in other words, it absorbs cadmium faster than it loses it—so specimens collected in the wild often have higher concentrations of this element than the soil in which they are found. Furthermore, when cultivated in the laboratory, the presence of cadmium in the culture medium stimulates growth up to 100% in the presence of 0.5 mg cadmium per liter of nutrient medium. It is believed that the cadmium-binding ability comes from a low molecular weight metal-binding protein
named cadmium-mycophosphatin.
, Mississippi
, Quebec
, Canada
, and Germany
.
Mushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Agaricus
Agaricus
Agaricus is a large and important genus of mushrooms containing both edible and poisonous species, with possibly over 300 members worldwide...
. It is commonly known as the abruptly-bulbous agaricus or the flat-bulb mushroom. First described by the mycologist Charles Horton Peck
Charles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...
, this bulbous-stemmed edible
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
species smells slightly of anise
Anise
Anise , Pimpinella anisum, also called aniseed, is a flowering plant in the family Apiaceae native to the eastern Mediterranean region and Southwest Asia. Its flavor resembles that of liquorice, fennel, and tarragon.- Biology :...
, and turns yellow when bruised or cut. The mushroom is medium-sized, with a white, yellow-staining cap on a slender stipe
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
that has a wide, flat bulb on the base
Taxonomy and classification
The species was originally named as Agaricus abruptus by American mycologist Charles Horton PeckCharles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...
in 1900. In his 1904 Report of the State Botanist publication, he changed the name to Agaricus abruptibulbus. He explained that Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...
had earlier named a species in the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Flammula, which he called Agaricus abruptus; the subgenus was later raised to the rank of genus, and the species was given the name Flammula abruptus. Under the transitioning nomenclatural conventions of the time, it was unclear if Agaricus abruptus would remain available for use, so he changed the name.
Agaricus abruptibulbus belongs in the Arvenses clade
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
of the genus Agaricus (along with species A. silvicola, A. arvensis, and A. semotus
Agaricus semotus
Agaricus semotus is a woodland mushroom of the Agaricales order of fungi. It, like many of its relatives, 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...
).
Some American authors consider this species to be synonymous with A. silvicola, while some in Europe have synonymized it with the similar species A. essettei. American mycologists Steve Trudell and Joseph Ammirati noted in a 2009 field guide: "The name A. abruptibulbus has been applied to forms with bulbous stipe bases, but variation in stipe shape is so great that the use of this name has been largely abandoned."
Description
The capPileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
is up to 8 cm (3.1 in) in diameter, convex in shape, sometimes with an umbo
Umbo (mycology)
thumb|right|[[Cantharellula umbonata]] has an umbo.thumb|right|The cap of [[Psilocybe makarorae]] is acutely papillate.An umbo is a raised area in the center of a mushroom cap. Caps that possess this feature are called umbonate. Umbos that are sharply pointed are called acute, while those that are...
, and whitish in color. After being scratched or bruised, the cap turns yellow. The stipe
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
is 8 – long by 1 – thick and bulbous. A large, white annular ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
is present on the stipe. The gill attachment is free, and the color is initially grayish but turns brownish after the spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s are developed. Specimens smell slightly of anise
Anise
Anise , Pimpinella anisum, also called aniseed, is a flowering plant in the family Apiaceae native to the eastern Mediterranean region and Southwest Asia. Its flavor resembles that of liquorice, fennel, and tarragon.- Biology :...
. The spore print
Spore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...
is brown to purple-brown. Spores are elliptical in shape, and are 6–8 by 4–5 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
. The surface of the cap will stain yellow if a drop of dilute potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
is applied.
Similar species
Agaricus silvicolaAgaricus silvicola
Agaricus silvicola, also known as the Wood Mushroom is a species of Agaricus mushroom related to the button mushroom.- Description :...
is very similar in appearance and also grows in woodlands, but it may be distinguished by the lack of an abruptly bulbous base. Agaricus arvensis
Agaricus arvensis
Agaricus arvensis, commonly known as the Horse Mushroom, is a mushroom of the genus Agaricus.-Taxonomy:Described as Agaricus arvensis by Jacob Christian Schaeffer in 1762, and given numerous binomial descriptions since. Its present name arvensis means 'of the field'.-Description:The cap is similar...
has a more robust stature, lacks the bulbous base, and grows in grassy open areas like meadows and fields. It has larger spores than A. abruptibulbus, typically 7.0–9.2 by 4.4–5.5 µm.
Cadmium bioaccumulation
Agaricus abruptibulbus is known to bioaccumulateBioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
the toxic element cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
—in other words, it absorbs cadmium faster than it loses it—so specimens collected in the wild often have higher concentrations of this element than the soil in which they are found. Furthermore, when cultivated in the laboratory, the presence of cadmium in the culture medium stimulates growth up to 100% in the presence of 0.5 mg cadmium per liter of nutrient medium. It is believed that the cadmium-binding ability comes from a low molecular weight metal-binding protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
named cadmium-mycophosphatin.
Distribution
The fungus has been reported in New YorkNew York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
, Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, and Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
.
External links
- Roger's Mushrooms
- Mushroom Hobby
- Mushroom of Quebec French language, with several photographs