''Russula virescens'' is a
basidiomycete
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...
mushroom
A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans.
The standard for the name "mushroom" is t ...
of the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Russula
''Russula'' is a very large genus composed of around 750 worldwide species of ectomycorrhizal mushrooms. They are typically common, fairly large, and brightly colored – making them one of the most recognizable genera among mycologists and mushr ...
'', and is commonly known as the green-cracking russula, the quilted green russula, or the green brittlegill. It can be recognized by its distinctive pale green
cap
A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...
that measures up to in diameter, the surface of which is covered with darker green angular patches. It has crowded white
gills
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
, and a firm, white
stipe that is up to tall and thick. Considered to be one of the best
edible mushroom
Edible mushrooms are the fleshy and edible fruit bodies of several species of macrofungi (fungi which bear fruiting structures that are large enough to be seen with the naked eye). They can appear either below ground (hypogeous) or above ground ...
s of the genus ''Russula'', it is especially popular in Spain and China. With a taste that is described variously as mild, nutty, fruity, or sweet, it is cooked by
grilling
Grilling is a form of cooking that involves dry heat applied to the surface of food, commonly from above, below or from the side. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat a ...
,
frying
Frying is the cooking of food in oil or another fat. Similar to sautéing, pan-fried foods are generally turned over once or twice during cooking to make sure that the food is well-made, using tongs or a spatula, while sautéed foods are cooked ...
,
sautéeing, or eaten raw. Mushrooms are rich in
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...
s and
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
, with a low
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers spec ...
content.
The species was described as new to science in 1774 by
Jacob Christian Schaeffer
Jacob (; ; ar, يَعْقُوب, Yaʿqūb; gr, Ἰακώβ, Iakṓb), later given the name Israel, is regarded as a patriarch of the Israelites and is an important figure in Abrahamic religions, such as Judaism, Christianity, and Islam. Ja ...
. Its distribution encompasses Asia, North Africa, Europe, and Central America. Its presence in North America has not been clarified, due to confusion with the similar species ''
Russula parvovirescens'' and ''
R. crustosa''. ''R. virescens'' fruits singly or scattered on the ground in both
deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
and
mixed forest
Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions.
These for ...
s, forming
mycorrhiza
A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant ...
l associations with broadleaf trees such as
oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
,
European beech
''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae.
Description
''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though mor ...
, and
aspen
Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section ''Populus'', of the ''Populus'' genus.
Species
These species are called aspens:
*'' Populus adenopoda'' – Chinese aspen (China ...
. In Asia, it associates with several species of tropical lowland
rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
trees of the family
Dipterocarpaceae
Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...
. ''R. virescens'' has a
ribonuclease
Ribonuclease (commonly abbreviated RNase) is a type of nuclease that catalyzes the degradation of RNA into smaller components. Ribonucleases can be divided into endoribonucleases and exoribonucleases, and comprise several sub-classes within the ...
enzyme with a
biochemistry
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...
unique among edible mushrooms. It also has
biologically active polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s, and a
laccase
Laccases () are multicopper oxidases found in plants, fungi, and bacteria. Laccases oxidize a variety of phenolic substrates, performing one-electron oxidations, leading to crosslinking. For example, laccases play a role in the formation of lign ...
enzyme that can break down several
dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...
s used in the laboratory and in the
textile industry
The textile industry is primarily concerned with the design, production and distribution of yarn, cloth and clothing. The raw material may be natural, or synthetic using products of the chemical industry.
Industry process
Cotton manufacturi ...
.
Taxonomy
![Russula virescens illustration 1898](https://upload.wikimedia.org/wikipedia/commons/3/3c/Russula_virescens_illustration_1898.jpg)
''Russula virescens'' was first described by German
polymath
A polymath ( el, πολυμαθής, , "having learned much"; la, homo universalis, "universal human") is an individual whose knowledge spans a substantial number of subjects, known to draw on complex bodies of knowledge to solve specific pro ...
Jacob Christian Schaeffer
Jacob (; ; ar, يَعْقُوب, Yaʿqūb; gr, Ἰακώβ, Iakṓb), later given the name Israel, is regarded as a patriarch of the Israelites and is an important figure in Abrahamic religions, such as Judaism, Christianity, and Islam. Ja ...
in 1774 as ''Agaricus virescens''.
The species was subsequently transferred to the genus ''Russula'' by
Elias Fries
Elias Magnus Fries (15 August 1794 – 8 February 1878) was a Swedish mycologist and botanist.
Career
Fries was born at Femsjö (Hylte Municipality), Småland, the son of the pastor there. He attended school in Växjö.
He acquired an ...
in 1836.
According to the
nomenclatural
Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally ag ...
authority
MycoBank
MycoBank is an online database, documenting new mycological names and combinations, eventually combined with descriptions and illustrations. It is run by the Westerdijk Fungal Biodiversity Institute in Utrecht.
Each novelty, after being screene ...
, ''Russula furcata'' var. ''aeruginosa'' (published by
Christian Hendrik Persoon
Christiaan Hendrik Persoon (1 February 1761 – 16 November 1836) was a German mycologist who made additions to Linnaeus' mushroom taxonomy.
Early life
Persoon was born in South Africa at the Cape of Good Hope, the third child of an imm ...
in 1796
) and ''Agaricus caseosus'' (published by
Karl Friedrich Wilhelm Wallroth
Karl Friedrich Wilhelm Wallroth (13 March 1792 in Breitenstein, Saxony-Anhalt – 22 March 1857 in Nordhausen, Thuringia, Nordhausen) was a German botanist. His name is abbreviated Wallr. as a taxon authority.
He attended classes in medicine ...
in 1883
) are
synonyms
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
of ''Russula virescens''.
The
variety
Variety may refer to:
Arts and entertainment Entertainment formats
* Variety (radio)
* Variety show, in theater and television
Films
* ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont
* ''Variety'' (1935 film), ...
''albidocitrina'', defined by
Claude Casimir Gillet
Claude Casimir Gillet (19 May 1806 in Dormans, department of Marne – 1 September 1896 in Alençon), was a French botanist and mycologist. He initially trained as a medical doctor and veterinarian.
As a veterinarian, he worked for four y ...
in 1876,
is no longer considered to have independent
taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
significance.
According to
Rolf Singer
Rolf Singer (June 23, 1906 – January 18, 1994) was a Germany, German-born mycologist and one of the most important Taxonomy (biology), taxonomists of gilled mushrooms (agarics) in the 20th century.
After receiving his Ph.D. at the University ...
's 1986
classification Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood.
Classification is the grouping of related facts into classes.
It may also refer to:
Business, organizat ...
of ''Russula'', ''R. virescens'' is the
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
of
subsection ''Virescentinae'' in section ''Rigidae'', a grouping of mushrooms characterized by a cap surface that breaks into patches of bran-like (furfuraceous) particles.
In a
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
analysis of European ''Russula'', ''R. virescens'' formed a
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
with ''
R. mustelina''; these two species were
sister
A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...
to a clade containing ''
R. amoenicolor'' and ''
R. violeipes''.
The
specific epithet
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
''virescens'' is
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for "becoming green".
The characteristic pattern of the cap surface has earned the species
common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...
s such as the green-cracking russula, the quilted green russula,
and the green brittlegill.
In the
mid-Atlantic United States, it is also known locally as the moldy russula.
Description
Described by mushroom enthusiast
Antonio Carluccio
Antonio Carluccio, OBE OMRI (; 19 April 1937 – 8 November 2017) was an Italian chef, restaurateur and food expert, based in London. He was called "the godfather of Italian gastronomy", with a career of more than 50 years. He is perhaps best r ...
as "not exactly nice to look at", the
cap
A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...
is at first dome or barrel-shaped, becoming convex and flattened with age with a diameter of up to . The cap center is often depressed.
The
cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
of the cap is green, most profoundly in the center, with patches of the same color dispersed radially around the center in an
areolate
Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their ...
pattern.
The color of the cuticle is often of variable shade, ranging from gray to
verdigris
Verdigris is the common name for blue-green, copper-based pigments that form a patina on copper, bronze, and brass. The technical literature is ambiguous as to its chemical composition. Some sources refer to "neutral verdigris" as copper(II) ac ...
to grass-green. The extent of the patching of the cuticle is also variable, giving specimens with limited patches a resemblance to other green-capped species of ''Russula'', such as ''
R. aeruginea''. The green patches of the cap lie on a white to pale green background. The cap, while frequently round, may also exhibit irregular lobes and cracks. The cap cuticle is thin, and can be readily peeled off the surface to a distance of about halfway towards the cap center.
The
gills
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
are white to cream colored, and fairly crowded together; they are mostly free from attachment to the
stipe. Gills are interconnected at their bases by veins.
The stipe is cylindrical, white, and of variable height, up to tall and wide;
it is roughly the same thickness at both the top and the base. The top portion of the stipe may be farinose—covered with a white, mealy powder.
It may turn slightly brown with age, or when it is injured or bruised from handling.
Like other mushrooms in the
Russulales
The Russulales are an order of the Agaricomycetes, (which include the agaric genera ''Russula'' and '' Lactarius'' and their polyporoid and corticioid relatives). According to the ''Dictionary of the Fungi'' (10th edition, 2008), the order con ...
, the
flesh
Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscle
Skeletal muscles (commonly referred to as mu ...
is brittle, owing to the sphaerocyst cytoarchitecture—cylindrical cells that contrast with the typical fibrous, filamentous
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
e present in other orders of the
basidiomycota
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...
.
![Russula virescens 105520](https://upload.wikimedia.org/wikipedia/commons/1/11/Russula_virescens_105520.jpg)
The
spores
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
of ''R. virescens'' are elliptical or
ellipsoid
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...
with warts, translucent (
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none.
Histopathology
Hyaline cartilage is ...
), and produce a white, pale or pale yellow
spore print
300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing pinkish-tan spore print. A 3.5-centimeter ...
;
the spore dimensions are 6–9 by 5–7
µm.
A partial reticulum (net-like pattern of ridges) interconnects the warts. The spore-bearing cells, the
basidia
A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...
, are club-shaped and have dimensions of 24–33 by 6–7.5 µm; they are colorless, and each hold from two to four spores. The pleurocystidia (
cystidia
A cystidium (plural cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that ar ...
on the gill face) are 40–85 by 6–8 µm and end abruptly in a sharp point.
Similar species
''Russula parvovirescens'', found in the eastern United States, can be distinguished from ''R. virescens'' by its smaller stature, with caps measuring wide and stipe up to long by thick. Compared to ''R. virescens'', it tends to be more bluish-green, the patches on its cap are larger, and it has a lined cap margin. Microscopically, the terminal cells in the cap cuticle of ''R. parvovirescens'' are more swollen than those of ''R. virescens'', which has tapered and elongated terminal cells.
Another green-capped ''Russula'' is ''
R. aeruginea'', but this species may be distinguished from ''R. virescens'' by its smaller size and smooth cap.
Other green russulas with a smooth cap include ''
R. heterophylla'' and
''R. cyanoxantha'' var. ''peltereaui''.
''
Russula crustosa
''Russula crustosa'', commonly known as the crusty russula, is a species of fungus in the family Russulaceae. It is found in Asia and North America.
Taxonomy
The species was first described scientifically by American mycologist Charles Horton ...
'', like ''R. virescens'', also has an areolate cap, but the cap becomes sticky (viscid) when moist, and its color is more variable, as it may be reddish, yellowish, or brown.
Also, the spore print of ''R. crustosa'' is a darker yellow than ''R. virescens''.
''
R. redolens'' has a cap that is "drab-green to blue-green", but unlike ''R. virescens'', is smooth. ''R. redolens'' has an unpleasant taste and smells of
parsley
Parsley, or garden parsley (''Petroselinum crispum'') is a species of flowering plant in the family Apiaceae that is native to the central and eastern Mediterranean region (Sardinia, Lebanon, Israel, Cyprus, Turkey, southern Italy, Greece, Por ...
.
Edibility
![Russula virescens 107410](https://upload.wikimedia.org/wikipedia/commons/8/83/Russula_virescens_107410.jpg)
''Russula virescens'' is an
edible mushroom
Edible mushrooms are the fleshy and edible fruit bodies of several species of macrofungi (fungi which bear fruiting structures that are large enough to be seen with the naked eye). They can appear either below ground (hypogeous) or above ground ...
considered to be one of the best of the genus ''Russula'', and is popular in Europe,
particularly in Spain.
In an 1875 work on the uses of fungi, English
mycologist
Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...
Mordecai Cubitt Cooke
Mordecai Cubitt Cooke (12 July 1825, in Horning, Norfolk – 12 November 1914, in Southsea, Hampshire) was an English botanist and mycologist who was, at various points, a London schoolteacher, a Kew mycologist, curator at the India Museum, jour ...
remarked about the mushroom that "the peasants about Milan are in the habit of putting
tover wood embers to toast, and eating
tafterwards with a little salt."
The mushroom is often sold as a dried product in Asia;
in China, it can be found in roadside markets,
and used in
traditional herbal medicines.
[Ying, J., et al. "Icones of medicinal fungi from China, Yuehan X, trans." (1987).] Its smell is not distinctive, but its taste has been described as mild, nutty,
fruity,
or even sweet.
Old specimens may smell of
herring
Herring are forage fish, mostly belonging to the family of Clupeidae.
Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, i ...
s.
Drying the mushrooms enhances the nutty flavor. Mushrooms can be
sautéed (the green color disappears with cooking), and young specimens that are prepared this way have a potato taste that pairs well with
shallot
The shallot is a botanical variety (a cultivar) of the onion. Until 2010, the (French red) shallot was classified as a separate species, ''Allium ascalonicum''. The taxon was synonymized with ''Allium cepa'' (the common onion) in 2010, as the d ...
s.
They are also fried or grilled,
or used raw in salads.
Young specimens are pale and can be hard to identify, but the characteristic pattern of older fruit bodies makes them hard to confuse with other species. When collecting ''R. virescens'' for consumption, caution is of vital importance to avoid confusion with the dangerously poisonous ''
Amanita phalloides
''Amanita phalloides'' (), commonly known as the death cap, is a deadly poisonous basidiomycete fungus, one of many in the genus ''Amanita''. Widely distributed across Europe, but now sprouting in other parts of the world, ''A. phalloides ...
'' (better known as the
death cap
''Amanita phalloides'' (), commonly known as the death cap, is a deadly poisonous basidiomycete fungus, one of many in the genus ''Amanita''. Widely distributed across Europe, but now sprouting in other parts of the world, ''A. phalloides ...
), a mushroom that can be most easily identified by its
volva and
ring
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
.
The nutritional components of ''R. virescens'' mushrooms have been characterized. Fresh mushrooms contain about 92.5% moisture. A sample of dried mushroom (100 g dw) has 365
kcal
The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of on ...
(1527
kilojoules
The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied ...
).
Carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...
s make up the bulk of the fruit bodies, comprising 62% of the dry weight; 11.1% of the carbohydrates are
sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...
s, the large majority of which (10.9%) is
mannitol
Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to lower ...
. The total
lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...
, or crude fat, content makes up 1.85% of the dry matter of the mushroom. The proportion of
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...
s (expressed as a percentage of total fatty acids) are 28.78%
saturated
Saturation, saturated, unsaturation or unsaturated may refer to:
Chemistry
* Saturation, a property of organic compounds referring to carbon-carbon bonds
** Saturated and unsaturated compounds
**Degree of unsaturation
** Saturated fat or fatty ac ...
, 41.51%
monounsaturated
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple est ...
, and 29.71%
polyunsaturated
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple e ...
. The most prevalent fatty acids include:
palmitic acid
Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...
, 17.3% of total fatty acids;
stearic acid
Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. ...
, 7.16%;
oleic acid
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...
, 40.27%; and
linoleic acid
Linoleic acid (LA) is an organic compound with the formula COOH(CH2)7CH=CHCH2CH=CH(CH2)4CH3. Both alkene groups are cis-trans isomerism, ''cis''. It is a fatty acid sometimes denoted 18:2 (n-6) or 18:2 ''cis''-9,12. A linoleate is a salt (chem ...
, 29.18%. Several
bioactive compounds are present in the mushroom. One hundred grams (dry weight) contains 49.3
microgram
In the metric system, a microgram or microgramme is a unit of mass equal to one millionth () of a gram. The unit symbol is μg according to the International System of Units (SI); the recommended symbol in the United States and United Kingdom whe ...
s (µg) of
tocopherol
Tocopherols (; TCP) are a class of organic chemical compounds (more precisely, various methylated phenols), many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, i ...
s (20.0 µg
alpha
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
, 21.3 µg
beta
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...
, and 8.0 µg
gamma
Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...
) and 0.19 milligrams (mg) of the
carotenoid
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...
pigment
lycopene
Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene (from the neo-Latin ''Lycopersicum'', the tomato species) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables.
Occu ...
. There are 4.46 g of
organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are rel ...
s per 100 g of dry mushrooms, including
oxalic acid
Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early inve ...
(0.78 g),
malic acid
Malic acid is an organic compound with the molecular formula . It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms ...
(2.71 g),
citric acid
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in t ...
(0.55 g), and
fumaric acid
Fumaric acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297.
The salts and esters are known as fu ...
(0.23 g). Mushrooms have 22.6 mg/100 g dw of the
phenolic
Phenolic is an adjective and a substantive (noun) that may apply to :
* Phenol (or carbolic acid), a colorless crystalline solid and aromatic compound
* Phenols, a class of chemical compounds that include phenol
* Phenolic content in wine
* Phenol ...
compound
4-hydroxybenzoic acid
4-Hydroxybenzoic acid, also known as ''p''-hydroxybenzoic acid (PHBA), is a monohydroxybenzoic acid, a phenolic derivative of benzoic acid. It is a white crystalline solid that is slightly soluble in water and chloroform but more soluble in pola ...
, and 15.8 mg/100 g dw of
cinnamic acid
Cinnamic acid is an organic compound with the formula C6H5-CH=CH- COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs n ...
.
Habitat and distribution
![Russula virescens 89201](https://upload.wikimedia.org/wikipedia/commons/c/c1/Russula_virescens_89201.jpg)
''Russula virescens'' can be found fruiting on soil in both
deciduous forests
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, afte ...
and
mixed forest
Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions.
These for ...
s,
forming
ectomycorrhiza
An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobi ...
l
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
relationships with a variety of trees, including oaks (''
Quercus
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably '' ...
''), European beech (''
Fagus sylvatica
''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae.
Description
''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though mor ...
''), and aspen (''
Populus tremula
''Populus tremula'' (commonly called aspen, common aspen, Eurasian aspen, European aspen, or quaking aspen) is a species of poplar native to cool temperate regions of Europe and Asia, from Iceland and the British IslesJames KilkellIrish native ...
'').
Preliminary investigations suggest that the fungus also associates with at least ten species of
Dipterocarpaceae
Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...
, an important tree family prevalent in the tropical lowland forests of
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
.
Fruit bodies may appear singly or in groups,
reappear in the same spots year after year, and are not common. In Europe, fruiting occurs mainly during the months of summer to early autumn.
A Mexican study of the seasonal occurrence of several common mushroom species in
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
forests in
Xalapa
Xalapa or Jalapa (, ), officially Xalapa-Enríquez (), is the capital city of the Mexican state of Veracruz and the name of the surrounding municipality. In the 2005 census the city reported a population of 387,879 and the municipality of which ...
showed that the fruiting period of ''R. virescens'' occurred in April, before the onset of the
rainy season
The rainy season is the time of year when most of a region's average annual rainfall occurs.
Rainy Season may also refer to:
* ''Rainy Season'' (short story), a 1989 short horror story by Stephen King
* "Rainy Season", a 2018 song by Monni
* ''T ...
.
The distribution of ''R. virescens'' in North America is subject to debate, where a number of similar species such as ''
R. parvovirescens'' and ''
R. crustosa'' are also recognized.
One author even suggests that ''R. virescens'' "is strictly a European species",
citing Buyck and collaborators (2006), who say "the ''virescens''-''crustosa'' group is much more complex than suspected and embraces at least a dozen taxa in the eastern US".
As in Europe, ''Russula virescens'' has a widespread distribution in Asia, having been recorded from India,
Malaysia,
Korea,
the Philippines,
Nepal,
China,
Thailand,
and Vietnam.
It is also found in North Africa and Central America.
Chemistry
''Russula virescens'' has a limited capacity to
bioaccumulate
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...
the
micronutrient
Micronutrients are nutrient, essential dietary elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements differ between organisms; for exam ...
s
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
,
copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
, and
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
from the soil. The concentration of these trace metals is slightly higher in the caps than the stipes. A meal of fresh mushroom caps would supply 16% of the
recommended daily allowance
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
(RDA) of copper for an adult male or female (ages 19–50); 16% or 7.3% of the RDA of iron for an adult male or female, respectively; and 16–22% of the adult RDA of zinc.
The mushroom is a poor bioaccumulator of the toxic
heavy metals
upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead
Heavy metals are generally defined as ...
arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
,
cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...
,
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
,
mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
, and
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
.
Biologically active mushroom
polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s have been a frequent research topic in recent decades due to their possible stimulatory effect on