Amanita gemmata
Encyclopedia
Amanita gemmata, commonly known as the gemmed Amanita or the jonquil Amanita, is a mushroom of the genus Amanita
Amanita
The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide. This genus is responsible for approximately 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own...

, a genus of fungi including some of the most deadly mushrooms, as well as notably psychoactive mushrooms. A. gemmata resembles the false death cap, tawny grisette
Amanita fulva
Amanita fulva, commonly called the tawny grisette, is a basidiomycete mushroom of the genus Amanita. It is found frequently in deciduous and coniferous forests of Europe, and possibly North America.-Taxonomy and naming:...

 and panther cap
Panther cap
Amanita pantherina var. pantherina, also known as the Panther cap and False Blusher due to its similarity to the true Blusher , is a species of Europe and western Asia.-Description:...

 mushrooms. Its pileus
Pileus (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...

 (cap) is a more bright color than in the former and more yellow than that of the latter two. Yet today it is still confused with various other European species.

Taxonomy and phylogeny

The species was first described
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...

 scientifically by Swedish mycologist and botanist Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...

 as Agaricus gemmatus in 1838. It was transferred to the genus Amanita in 1866 by the French statistician Louis Bertillon
Louis Bertillon
Louis-Adolphe Bertillon was a French statistician and appointed professor of demography at the school of anthropology in Paris.His son Alphonse Bertillon is known for the invention of anthropometry, and another son Jacques also became a notable statistician.-External links:*...

. The species has been transferred to several genera in its history, resulting in a number of synonyms
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

, including Amanita muscaria var. gemmata (1886, Lucien Quélet
Lucien Quélet
thumb|Lucien QuéletLucien Quélet was a French mycologist and naturalist who discovered several species and was the founder of the Société mycologique de France, a society devoted to mycological studies....

), Amanitopsis gemmata (1887, Pier Andrea Saccardo
Pier Andrea Saccardo
Pier Andrea Saccardo was an Italian botanist and mycologist.- Life :...

), Amanitaria gemmata (1940, Jean-Edouard Gilbert), and Venenarius gemmatus (1948, William Murrill
William Murrill
William Alphonso Murrill was an American mycologist, known for his contributions to the knowledge of the Agaricales and Polyporaceae.- Education :...

).

Two molecular studies based on sequences of the large ribosomal subunit RNA gene (nLSU-rDNA) and the mitochondrial small ribosomal subunit RNA gene (mtSSU-rDNA) show that Amanita gemmata is part of a subgroup within Amanita
Amanita
The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide. This genus is responsible for approximately 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own...

with its close relatives the fly agaric (Amanita muscaria
Amanita muscaria
Amanita muscaria, commonly known as the fly agaric or fly amanita , is a poisonous and psychoactive basidiomycete fungus, one of many in the genus Amanita...

), A. farinosa
Amanita farinosa
Amanita farinosa, also called Eastern American Floury Amanita, is a North American poisonous mushroom of the genus Amanita, a genus of fungi including some of the most deadly mushrooms, as well as notably psychedelic mushrooms.-Taxonomy:...

and A. roseitincta. It is deadly poisonous, and causes symptoms as in A. pantherina poisoning. Amanita gemmata is a hallucinogenic mushroom which contains ibotenic acid
Ibotenic acid
Ibotenic acid is a chemical compound that is naturally occurring in the mushrooms Amanita muscaria and Amanita pantherina, among others...

 and muscimol
Muscimol
Muscimol is the major psychoactive alkaloid present in many mushrooms of the Amanita genus. Unlike psilocin , which is a serotonergic psychedelic and agonist for the 5-HT2A receptor set, muscimol is a potent, selective agonist for the GABAA receptor set and is a deliriant as a opposed...

.

The mushroom is commonly
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 known as the "gemmed Amanita", the "jonquil Amanita", or the "European gemmed Amanita".

Description

The fruit bodies
Basidiocarp
In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...

 are colored yellow overall. The fresh cap
Pileus (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...

, ranging in color from dull creamy yellow to golden yellow to buff, is sticky when moist. White warts adorn the cap surface, but they are usually flimsy and easily washed away by rain; they even seem as though they might easily slide off the wet cap surface with no more than gravity to encourage them. The cap is typically 4 – in diameter, initially convex before flattening out in maturity. The gills are adnate
Adnation
Adnation in plants is the "union of unlike parts; organically united or fused with another dissimilar part, e.g. an ovary to a calyx tube, or stamens to petals". This is in contrast to connation, the fusion of similar organs....

 to adnexed, and white; they are close together, with little intervening space. The pale yellowish stem
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 5 – long by 0.5 – thick, and either roughly equal in width throughout, or slightly thicker at the base. Young mushrooms have a membranous partial veil
Partial veil
thumb|150px|right|Developmental stages of [[Agaricus campestris]] showing the role and evolution of a partial veilPartial veil is a mycological term used to describe a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics...

 extending from the upper stem to the cap margin; as the mushroom grows, the partial veil tears to leave a flimsy, skirt-like, easily-lost 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...

 on the stem. At the base of the stem is a flimsy white volva
Volva (mycology)
The volva is a mycological term to describe a cup-like structure at the base of a mushroom that is a remnant of the universal veil. This macrofeature is important in wild mushroom identification due to it being an easily observed, taxonomically significant feature which frequently signifies a...

 (a remnant of the universal veil
Universal veil
In mycology, a universal veil is a temporary membranous tissue that fully envelops immature fruiting bodies of certain gilled mushrooms. The developing Caesar's mushroom , for example, which may resemble a small white sphere at this point, is protected by this structure...

 that covered the immature mushroom) that usually forms a small, free rim. 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...

s are white.

Amanita gemmata has ellipsoid to broadly ellipsoid 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 measuring 8–10 by 6.5–7.5 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...

 with an average Q-ratio (the fraction of length/width) of 1.35; the spores are not amyloid
Amyloid (mycology)
In mycology the term amyloid refers to a crude chemical test using iodine in either Melzer's reagent or Lugol's solution, to produce a black to blue-black positive reaction. It is called amyloid because starch gives a similar reaction, and that reaction for starch is also called an amyloid reaction...

. The surface of the thin-walled spores is smooth, and they contains one to several small oil droplets. The basidia (spore-bearing cells of the hymenium
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...

) are mostly unclamped.

Toxicity

The species was implicated in several poisonings (including one death) in the Chilean province of Malleco between 1986 and 1990. Symptoms were similar to that caused by ingestion of Amanita phalloides, including acute gastroenteritis
Gastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...

 and acute hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...

.

Similar species

There are numerous forms in North America that tend to integrate with A. pantherina. In 2005, Rod Tulloss described Amanita aprica
Amanita aprica
Amanita aprica is a species of fungus in the Amanitaceae family. Described as new to science in 2005, the species is found in the Pacific Northwest region of North America, where it grows in a mycorrhizal association with Douglas-fir and pines....

, a species that has been confused with A. gemmata several times in the past.

Ecology, habitat and distribution

Amanita gemmata is a mycorrhizal fungus, meaning it forms a mutually beneficial relationship with the roots of compatible host plants. Through the association, the plant provides the fungus with a carbon source, and the fungus provides the plant with several benefits such as nutrients and protection from pathogens. Largent & collaborators (1980) document mycorrhizal association of Amanita gemmata with manzanita
Manzanita
Manzanita is a common name for many species of the genus Arctostaphylos. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from southern British Columbia, Washington to California, Arizona and New Mexico in the United States, and...

 and lodgepole pine
Lodgepole Pine
Lodgepole Pine, Pinus contorta, also known as Shore Pine, is a common tree in western North America. Like all pines, it is evergreen.-Subspecies:...

, and Nieto and Carbone with maritime pine
Maritime Pine
Pinus pinaster, the Maritime Pine, is a pine native to the western and southwestern Mediterranean region. The pejorative name 'pinaster' is derived from pinus + aster, translating as 'a poor imitation of a pine' Pinus pinaster, the Maritime Pine, is a pine native to the western and southwestern...

 (Pinus pinaster) in Spain. It favors sandy and slightly acidic soils and often in association with Norway Spruce
Norway Spruce
Norway Spruce is a species of spruce native to Europe. It is also commonly referred to as the European Spruce.- Description :...

 (Picea abies). The mushroom grows either solitarily, scattered, or in groups in coniferous and mixed forest, especially along paths and roads.

The species is distributed in areas of the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 and Europe. It grows in summer and fall (fall and winter in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

). It is widely distributed (as a species cluster) in North America; it has been found as far south as Ixtlán de Juárez
Ixtlán de Juárez
Ixtlán de Juárez is a town and municipality in the Mexican state of Oaxaca about 65 km north of the city of Oaxaca on Federal Highway 175 towards Veracruz.It is part of the Ixtlán District in the Sierra Norte de Oaxaca region.-Municipality of Ixtlán:...

, Mexico. The species has been reported from the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...

. In South America, it is known from Chile. In Central Europe, it is found between June and October. The mushroom has also been collected from Iran.
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