Amanita rubrovolvata
Encyclopedia
Amanita rubrovolvata, commonly known as the red volva Amanita, is a species of fungus
in the Amanitaceae
family. First described scientifically by the Japanese mycologist S. Imai in 1939, it is widely distributed in eastern Asia. The fungus produces small- to medium-sized mushroom
s, with reddish-orange caps
up to 6.5 mm (0.255905511811024 in) wide. The stems
are up to 100 mm (3.9 in) tall, cream above the ring
and cream to yellowish below it. The stem ends in a roughly spherical bulb at the base, which is covered with bright orange patches. Neither edibility
nor toxicity have been established for the fungus, but it is suspected to be associated with neurological anomalies. Several molecular studies have confirmed the mushroom's classification in the subgenus
Amanita of the genus Amanita
, along with closely related species such as A. muscaria
.
by the Japanese mycologist Sanshi Imai in 1939, based on various collections made in Japan during 1933–38. Imai designated the Japanese name for mushroom as Hime-beni-tengutake (ヒメベニテングタケ). According to the online taxonomical database MycoBank
, the name Amplariella rubrovolvata, proposed by French mycologist Jean-Edouard Gilbert in 1941, is a synonym
; the generic name Amplariella has since been subsumed into Amanita.
Amanita rubrovolvata is classified in the subgenus
Amanita of the genus Amanita
, according to the systems proposed by Cornelis Bas
(1969), and Rolf Singer
(1986). It was one of 49 Amanita species included in a 1998 molecular phylogenetic analysis intended to help clarify natural groups and phylogenetic relationships within the genus. In the cladogram
, A. rubrovolvata is on a branch next to a cluster of species including A. pantherina var. lutea, A. gemmata
, A. farinosa
, and A. sinensis. These results were comparable to those published in later phylogenetic analyses (1999, 2004, 2010) that have included A. rubrovolata as part of a larger dataset.
The specific epithet rubrovolvata is derived from the Latin
words ruber ("red"), and the adjective volvatus ("closely sheathed"). Amanita authority Rodham E. Tulloss has suggested "red volva Amanita" as an appropriate common name
.
of A. rubrovolvata is 2 – wide, convex to flattened, sometimes with a slight umbo
. They are dark red to reddish-orange, becoming a paler orange to yellowish at the margin. The cap surface is densely covered with red to orange to yellow, powdery to granular remnants of the volva
. The cap margin is grooved—with the grooves extending to between 30% to 60% of the radius—and does not have partial veil
remnants hanging along the cap margin. The flesh
of the mushroom is white to yellow, or reddish immediately beneath the cap cuticle
. The white gills are free from attachment to the stem and are 3 to 6 mm (0.118110236220472 to 0.236220472440945 in) broad. The lamellulae (short gills that do not extend fully from the cap edge to the stem) are truncate, and typically range in length between 15–50% of the length of the gills.
The stem
is 50 – by 5 – thick, roughly cylindrical or slightly larger upwards, with a surface that is cream above the ring
and cream to yellowish below. The bulb at the base of the stem is roughly spherical, and 1 – wide, with its upper part covered with red, orange to yellow woolly to powdery remnants of the volva
. The volva remains in mature specimens as a ring around the upper part of the stem bulb. The ring
is membranous, persistent, with an upper surface that is white and a lower surface having a yellowish tinge and an edge that is red to orange.
Amanita rubrovolvata produces a white to cream-colored spore print
. The spore
s are spherical or nearly so, and typically measure 7.5–9.0 by 7.0–8.5 µm
. They are inamyloid
, meaning that they will not absorb iodine
stain from Melzer's reagent
. The basidia (spore-bearing cells in the hymenium
) are club-shaped, four-spored (rarely two-spored), and measure 25–44 by 10–14 µm. The sterigmata (slender extensions at the basidial tips that attach to the spores) are 3–4 µm long, and clamps are not found on the bases of basidia.
Although the edibility
or toxicity of the mushroom is not known with certainty, it has been reported to cause "neurological symptoms" in mice, as well as increased levels of blood glucose and decreased blood urea nitrogen
. Other biochemical changes reported in mice, after peritoneal
injection of fruit body extract, include decreases in the activity of the enzyme acetylcholinesterase
and reduced levels of liver glycogen
. In these experiments, values returned to normal six hours after initial injection, suggesting that the poisoning was not serious, and did not affect liver and kidney performance.
resembles A. rubrovoltata slightly, but the former has short grooves at the edge of a yellowish-orange cap, slightly larger spores, a yellow volva, and clamps at the basidial bases. Roger Heim
reported A. frostiana as occurring in Thailand, but this was probably a misidentification of A. rubrovolvata.
(Fagus crenata), but it has also been found growing near Quercus luecotrichophora, Rhododendron arboreum
, and Myrica esculenta
in India, in Castanopsis
-Schima
forest in Nepal, and in Castanopsis indica plantations in the Himalayas.
The species occurs in China, northern India, Nepal, Gharwal Himalaya, South Korea, and countries of Southeast Asia (for example, Thailand). The southern limit of the distribution extends to southern Malay Peninsula
.
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
in the Amanitaceae
Amanitaceae
Amanitaceae are a family of fungi or mushrooms. The family, also commonly called the Amanita family, is in order Agaricales, gilled mushrooms...
family. First described scientifically by the Japanese mycologist S. Imai in 1939, it is widely distributed in eastern Asia. The fungus produces small- to medium-sized mushroom
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...
s, with reddish-orange caps
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...
up to 6.5 mm (0.255905511811024 in) wide. The stems
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...
are up to 100 mm (3.9 in) tall, cream above the 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...
and cream to yellowish below it. The stem ends in a roughly spherical bulb at the base, which is covered with bright orange patches. Neither edibility
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...
nor toxicity have been established for the fungus, but it is suspected to be associated with neurological anomalies. Several molecular studies have confirmed the mushroom's classification 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...
Amanita 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...
, along with closely related species such as A. 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...
.
Taxonomy, phylogeny, and naming
The species was first described scientificallySpecies 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...
by the Japanese mycologist Sanshi Imai in 1939, based on various collections made in Japan during 1933–38. Imai designated the Japanese name for mushroom as Hime-beni-tengutake (ヒメベニテングタケ). According to the online taxonomical database MycoBank
MycoBank
MycoBank is an online database, documenting new mycological names and combinations, eventually combined with descriptions and illustrations. It is run by the Centraalbureau voor Schimmelcultures fungal biodiversity center in Utrecht....
, the name Amplariella rubrovolvata, proposed by French mycologist Jean-Edouard Gilbert in 1941, is a synonym
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...
; the generic name Amplariella has since been subsumed into Amanita.
Amanita rubrovolvata is classified 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...
Amanita 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...
, according to the systems proposed by Cornelis Bas
Cornelis Bas
Dr. Cornelis Bas is a noted Dutch mycologist.Dr. Bas was born in Rotterdam and graduated in Biology at Leiden University in 1954. In 1953, he began working at the National Herbarium of the Netherlands, as curator for the fungi, in particular, the Agaricales...
(1969), and Rolf Singer
Rolf Singer
Rolf Singer was a German-born mycologist and one of the most important taxonomists of gilled mushrooms in the 20th century....
(1986). It was one of 49 Amanita species included in a 1998 molecular phylogenetic analysis intended to help clarify natural groups and phylogenetic relationships within the genus. In the cladogram
Cladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
, A. rubrovolvata is on a branch next to a cluster of species including A. pantherina var. lutea, A. gemmata
Amanita gemmata
Amanita gemmata, commonly known as the gemmed Amanita or the jonquil Amanita, is a mushroom of the genus Amanita, 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 and panther cap mushrooms...
, 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. sinensis. These results were comparable to those published in later phylogenetic analyses (1999, 2004, 2010) that have included A. rubrovolata as part of a larger dataset.
The specific epithet rubrovolvata is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
words ruber ("red"), and the adjective volvatus ("closely sheathed"). Amanita authority Rodham E. Tulloss has suggested "red volva Amanita" as an appropriate common name
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...
.
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...
of A. rubrovolvata is 2 – wide, convex to flattened, sometimes with a slight 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...
. They are dark red to reddish-orange, becoming a paler orange to yellowish at the margin. The cap surface is densely covered with red to orange to yellow, powdery to granular remnants of the 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...
. The cap margin is grooved—with the grooves extending to between 30% to 60% of the radius—and does not have 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...
remnants hanging along the cap margin. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
of the mushroom is white to yellow, or reddish immediately beneath the cap cuticle
Pileipellis
thumb|300px||right|The cuticle of some mushrooms, such as [[Russula mustelina]] shown here, can be peeled from the cap, and may be useful as an identification feature....
. The white gills are free from attachment to the stem and are 3 to 6 mm (0.118110236220472 to 0.236220472440945 in) broad. The lamellulae (short gills that do not extend fully from the cap edge to the stem) are truncate, and typically range in length between 15–50% of the length of the gills.
The 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 50 – by 5 – thick, roughly cylindrical or slightly larger upwards, with a surface that is cream above the 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...
and cream to yellowish below. The bulb at the base of the stem is roughly spherical, and 1 – wide, with its upper part covered with red, orange to yellow woolly to powdery remnants of the 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...
. The volva remains in mature specimens as a ring around the upper part of the stem bulb. The 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 membranous, persistent, with an upper surface that is white and a lower surface having a yellowish tinge and an edge that is red to orange.
Amanita rubrovolvata produces a white to cream-colored 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...
. 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 spherical or nearly so, and typically measure 7.5–9.0 by 7.0–8.5 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...
. They are inamyloid
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...
, meaning that they will not absorb iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
stain from Melzer's reagent
Melzer's Reagent
Melzer's reagent is a chemical reagent used by mycologists to assist with the identification of fungi.-Composition:...
. The basidia (spore-bearing cells in 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 club-shaped, four-spored (rarely two-spored), and measure 25–44 by 10–14 µm. The sterigmata (slender extensions at the basidial tips that attach to the spores) are 3–4 µm long, and clamps are not found on the bases of basidia.
Although the edibility
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...
or toxicity of the mushroom is not known with certainty, it has been reported to cause "neurological symptoms" in mice, as well as increased levels of blood glucose and decreased blood urea nitrogen
Blood urea nitrogen
The blood urea nitrogen test is a measure of the amount of nitrogen in the blood in the form of urea, and a measurement of renal function. Urea is a by- product from metabolism of proteins by the liver and is removed from the blood by the kidneys.-Physiology:The liver produces urea in the urea...
. Other biochemical changes reported in mice, after peritoneal
Peritoneum
The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
injection of fruit body extract, include decreases in the activity of the enzyme acetylcholinesterase
Acetylcholinesterase
"Acetylcholinesterase, also known as AChE or acetylcholine acetylhydrolase, is an enzyme that degrades the neurotransmitter acetylcholine, producing choline and an acetate group. It is mainly found at neuromuscular junctions and cholinergic nervous system, where its activity serves to terminate...
and reduced levels of liver glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
. In these experiments, values returned to normal six hours after initial injection, suggesting that the poisoning was not serious, and did not affect liver and kidney performance.
Similar species
Sanmee and colleagues mention that the eastern North American species A. frostianaAmanita frostiana
Amanita frostiana, also known as Frost's Amanita, is a small fungi species of eastern U.S.A. and southeastern Canada. The mushroom varies in colours from yellow, red or reddish pink usually.-Physical description:...
resembles A. rubrovoltata slightly, but the former has short grooves at the edge of a yellowish-orange cap, slightly larger spores, a yellow volva, and clamps at the basidial bases. Roger Heim
Roger Heim
Roger Heim was a French botanist specialising in mycology and tropical phytopathology. He was known for his studies describing the anatomy of the mushroom hymenium, the systematics and phylogeny of higher fungi , the mycology of tropical fungi such as...
reported A. frostiana as occurring in Thailand, but this was probably a misidentification of A. rubrovolvata.
Habitat and distribution
Amanita rubrovoltata mushrooms grow in groups on the ground. Amanita species form mycorrhizal relationships with trees. This is a mutually beneficial relationship where the hyphae of the fungus grow around the roots of trees, enabling the fungus to receive moisture, protection and nutritive byproducts of the tree, and affording the tree greater access to soil nutrients. The original Japanese collections were made in forests dominated by Japanese beechJapanese Beech
The name Japanese Beech can refer to two different species of beech tree, both native to Japan.*Fagus crenata, also called Siebold's Beech*Fagus japonica, also called Japanese Blue Beech...
(Fagus crenata), but it has also been found growing near Quercus luecotrichophora, Rhododendron arboreum
Rhododendron arboreum
Rhododendron arboreum is an evergreen shrub or small tree with a showy display of bright red flowers. It is found in Bhutan, China, India, Nepal, Sri Lanka and Thailand. Rhododendron arboreum is also the national flower of Nepal.-Description:Its name means "tending to be woody or growing in a...
, and Myrica esculenta
Myrica esculenta
Myrica esculenta is a small tree or large shrub native to Hills of Nepal and northern India. Its common names include Box myrtle, Bayberry...
in India, in Castanopsis
Castanopsis
Castanopsis is a genus of evergreen trees belonging to the beech family, Fagaceae. The genus contains about 120 species, which are today restricted to tropical and subtropical eastern Asia. A total of 58 species are native to China, with 30 endemic; the other species occur further south, through...
-Schima
Schima
[[Schima is a [[genus]] of evergreen trees belonging to the tea family, [[Theaceae]].The genus inhabits warm temperate to subtropical climates across southern and southeastern Asia, from the eastern [[Himalaya]] of [[Nepal]] and eastern [[India]] across [[Indochina]], southern [[China]],...
forest in Nepal, and in Castanopsis indica plantations in the Himalayas.
The species occurs in China, northern India, Nepal, Gharwal Himalaya, South Korea, and countries of Southeast Asia (for example, Thailand). The southern limit of the distribution extends to southern Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
.