Lactarius torminosus
Encyclopedia
Lactarius torminosus, commonly known as the woolly milkcap or the bearded milkcap, is a large basidiomycete fungus
in the genus Lactarius
. It is found in the United Kingdom, Northern Europe, and is common in North America, where it grows in mixed forests in a mycorrhiza
l association with various trees, most commonly birch
. Although it is valued for its peppery flavour and eaten after pickling in Russia and Finland, it is highly irritating to the digestive system when eaten raw. The toxins responsible for the acrid taste are destroyed by cooking.
The fruit bodies
produced by the fungus have caps
which can reach up to 10 cm (3.9 in) in diameter. They are pink-flesh coloured, with whitish concentric zones. The edge of the cap is rolled inwards, and shaggy when young. On the underside of the caps are flesh-colored gills crowded closely together. It is on these fertile gill surfaces that the spore
-bearing cells, the basidia are found. The cylindrical stem
is a pale flesh colour with a delicately downy surface, reaching lengths of up to 8 cm (3.1 in). When cut or injured, the fruit bodies ooze a white latex
that does not change colour upon exposure to air. The variety normandensis, in contrast, has latex that changes colour from white to yellow.
in 1774; he named it Agaricus torminosus. Seven years later in 1781, Jean Bulliard
named a species Agaricus necator and illustrated it in the first volume of his Herbier de la France. This name, and its later name Lactarius necator (transferred to Lactarius in 1800 by Persoon
), are now considered synonymous
with L. torminosus. Other names that have been given to the species, and are now consider synonyms, include Lactarius necans (Gray
, 1821), Galorrheus torminosus (Kummer
, 1871), and Lactifluus torminosus (Kuntze
, 1891). The specific epithet torminosus means "tormenting" or "causing colic", and refers to the fact that it causes gastrointestinal distress. It is commonly
known as the "shaggy milkcap", the "pink-fringed milkcap", the "woolly milkcap" (alternatively spelled wooly), or the "bearded milkcap".
Lactarius torminosus is classified
in the subgenus
Piperites, section Piperites (in which it is the type species
), subsection Piperites of the genus Lactarius
. Species in this subsection are characterised by having latex
that does not turn yellow after exposure to air, and/or which do not stain the cut surface of the mushroom surface yellow. A 2004 phylogenetic analysis of European Lactarius species concluded that L. torminosus fall into a well-supported group that includes L. torminosulus, and that these two species are phylogenetically close to a group that includes L. tesquorum, L. scoticus, and L. pubescens
.
is initially convex, but as it matures, the center of the cap forms a depression, and the outer edges become raised until eventually it assumes the shape of a shallow funnel; its width is typically between 2 and 12 cm (0.78740157480315 and 4.7 in). The margin (edge of the cap) is curled inwards, and when young is covered with a dense thicket of "hair" that withers in age to whitish fibers. Similarly, the cap surface is initially tomentose (covered with a thick matting of hairs) but eventually the hairs wear off, leaving the surface smooth. The surface is sticky to viscid and smooth on the central portion in early stages, often with whitish concentric zones. The overall cap color is pinkish-orange to pale dull pink, becoming orange to whitish on the margin, with the pink gradually fading. The white to flesh-colored flesh
is firm, but becomes flaccid in age. The latex
that is produced when the mushroom tissue in cut or injured is white to cream, and does not change color with prolonged exposure to air, nor does it stain the gills. It has an acrid taste, with a slight to pungent odor.
The gills are short-decurrent (running a little ways down the length of the stem), close to crowded together, narrow, and are sometimes forked near the stem. Their colour is whitish, becoming pale vinaceous (the colour of red wine) to pale orange or cream tinged vinaceous, turning pale tan with age. The stem
is 1.5 – long, 0.6 – thick, fragile, more or less equal in width throughout, cylindrical or narrowed at the base. The surface of the stem is dry, and either smooth to pruinose (with a very fine whitish powder on the surface). Its colour is pale light pinkish to yellowish tinged or slightly pinkish orange to orange white, sometimes spotted. The flesh of the stem is firm, beige white, and stuffed (as if filled with cotton), but it eventually becomes hollow.
of L. torminosus is cream to pale yellow. The spores are 8–10.2 by 5.8–6.6 μm
, roughly spherical to broadly elliptic in side view, and hyaline
(translucent). The ornamentation on the surface of the spores is amyloid
, partially reticulate, with interrupted ridges and a few isolated warts. The prominences are roughly 0.5–0.7 μm high, with a prominent apiculus. The basidia (spore-bearing cells) are 30–47.7 by 7.3–8.2 μm, four-spored, club-shaped to cylindrical, and hyaline. The pleurocystidia are only present in the form of macrocystidia (very long cystidia) embedded and originating in the hymenium
and just below it, measuring 40.3–80.0 by 5.1–9.5 μm. The macrocystidia are abundant, spindle-shaped to ventricose (swollen on one side), gradually tapering in width, with granular hyaline contents. The cheilocystidia are 30–52 by 4.5–8.0 μm, also in the form of macrocystidia.
in 1960 to account for the North American species closely resembling L. torminosus, but having instead latex which changed colour from white to yellow upon exposure, and which stained tissues and paper yellow. Hesler
and Smith reduced this taxon to the status of variety in 1979. Lactarius torminosus var. normandensis has been collected from Idaho
, Michigan
and Wisconsin
in the United States, from Quebec
in Canada, and from Switzerland. The variety resembles Lactarius pubescens
var. betulae, but differs in its longer pleurocystidia, larger spores with slightly different spore ornamentation, and its strongly burning acrid taste. The holotype
specimen, collected by Smith near Nordman, Idaho
in 1956, is kept in the fungus collection at the University of Michigan
Herbarium.
, Russia
and other North European countries it is eaten, after boiling or five-day soaking, pickled and valued for its hot, burning taste. In Norway it is roasted, and added to coffee. The nutritive composition of the fruit bodies of Finnish specimens has been analysed and found to contain the following components (as a percentage of dry weight
): protein
, 17.2%; phosphorus
, 0.46%; calcium
, 0.12%; magnesium
, 0.088%; potassium
, 2.97%; sodium
0.011%.
resemble L. torminosus, but they have a white latex that soon changes yellow upon exposure to air, and their stems have depressed shiny spots. The caps of the poorly known species L. cilicioides are zoned, and its spores are smaller. L. pubescens
is physically quite similar, but can be distinguished by its paler colour and smaller spores (6–8.5 by 5–6.5 μm). L. controversus
has a cap margin that is not as hairy, whitish to cream-coloured gills, and larger spores measuring 7.5–10 by 6–7.5 μm.
) in mixed forests. It is also known to grow in urban settings where birch trees are nearby. Fruit bodies grow on the ground, scattered to grouped together. It is found throughout the United Kingdom, Northern Europe, and is common in North America, where it sometimes grows with aspen
(Populus species). The North American distribution extends north into the Yukon
and Alaska
, and south to Mexico.
The fruit bodies are a component of the diet of the red squirrel Sciurus vulgaris. Lactarius torminosus mushrooms may be parasitized by the mold Hypomyces lithuanicus.
lactone
15-hydroxyblennin A. This sesquiterpenoid has a lactarane skeleton
, similar to compounds found in other Lactarius species, such as Lactarius deliciosus
, Lactarius blennius
(blennin A), and Lactarius rufus
(lactarorufin N, deoxydihydroketolactarorufin N). Fruit bodies contain a number of sterol
s, of which ergosterol
is the predominant component at 60.5% (of total sterols), followed by the ergosterol derivatives ergost-7-en-3-ol (13.7%), ergosta-7-22-dien-3-ol (8.3%), and ergosta-5/7-dien-3-ol (17.0%). The mushrooms also contain the compound velleral, a breakdown
product of stearyl-velutinal, which is contained within the lactifers—specialized hyphal cells that produced the mushroom's latex. It has been suggested that broken lactifers leak precursors whose breakdown products act as defensive agents toxic to humans and effectively deter certain vertebrates that might consume the mushroom. Velleral, which has an extremely pungent taste and is thought to be responsible for the toxicity of the raw mushroom, is present at a concentration of 0.16 mg/g mushroom.
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 genus Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
. It is found in the United Kingdom, Northern Europe, and is common in North America, where it grows in mixed forests in a mycorrhiza
Mycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
l association with various trees, most commonly birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
. Although it is valued for its peppery flavour and eaten after pickling in Russia and Finland, it is highly irritating to the digestive system when eaten raw. The toxins responsible for the acrid taste are destroyed by cooking.
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...
produced by the fungus have 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...
which can reach up to 10 cm (3.9 in) in diameter. They are pink-flesh coloured, with whitish concentric zones. The edge of the cap is rolled inwards, and shaggy when young. On the underside of the caps are flesh-colored gills crowded closely together. It is on these fertile gill surfaces that 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...
-bearing cells, the basidia are found. The cylindrical 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 a pale flesh colour with a delicately downy surface, reaching lengths of up to 8 cm (3.1 in). When cut or injured, the fruit bodies ooze a white latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
that does not change colour upon exposure to air. The variety normandensis, in contrast, has latex that changes colour from white to yellow.
Taxonomy, classification, and phylogeny
The species was originally described scientifically by the German naturalist Jacob Christian SchäfferJacob Christian Schäffer
Jakob or Jacob Christian Gottlieb Schäffer or Schäffern was a German dean, professor, botanist, mycologist, entomologist, ornithologist and inventor.-Biography:...
in 1774; he named it Agaricus torminosus. Seven years later in 1781, Jean Bulliard
Jean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard was a French physician and botanist....
named a species Agaricus necator and illustrated it in the first volume of his Herbier de la France. This name, and its later name Lactarius necator (transferred to Lactarius in 1800 by Persoon
Christian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
), are now considered synonymous
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...
with L. torminosus. Other names that have been given to the species, and are now consider synonyms, include Lactarius necans (Gray
Samuel Frederick Gray
Samuel Frederick Gray was a British botanist, mycologist, and pharmacologist. He was the father of the zoologists John Edward Gray and George Robert Gray.-Background:...
, 1821), Galorrheus torminosus (Kummer
Paul Kummer
Paul Kummer was a priest, teacher, and scientist in Zerbst, Germany, known chiefly for his contribution to mycological nomenclature. Earlier classification of agarics by pioneering fungal taxonomist Elias Magnus Fries designated only a very small number of genera, with most species falling into...
, 1871), and Lactifluus torminosus (Kuntze
Otto Kuntze
Otto Carl Ernst Kuntze was a German botanist.-Biography:Otto Kuntze was born in Leipzig.An apothecary in his early career, he published an essay entitled Pocket Fauna of Leipzig. Between 1863 and...
, 1891). The specific epithet torminosus means "tormenting" or "causing colic", and refers to the fact that it causes gastrointestinal distress. It 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 "shaggy milkcap", the "pink-fringed milkcap", the "woolly milkcap" (alternatively spelled wooly), or the "bearded milkcap".
Lactarius torminosus is classified
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
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...
Piperites, section Piperites (in which it is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
), subsection Piperites of the genus Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
. Species in this subsection are characterised by having latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
that does not turn yellow after exposure to air, and/or which do not stain the cut surface of the mushroom surface yellow. A 2004 phylogenetic analysis of European Lactarius species concluded that L. torminosus fall into a well-supported group that includes L. torminosulus, and that these two species are phylogenetically close to a group that includes L. tesquorum, L. scoticus, and L. pubescens
Lactarius pubescens
Lactarius pubescens, commonly known as the downy milk cap, is a species of fungus in the Russulaceae family. It is a medium to large agaric with a creamy-buff, hairy cap, whitish gills and short stout stem...
.
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 initially convex, but as it matures, the center of the cap forms a depression, and the outer edges become raised until eventually it assumes the shape of a shallow funnel; its width is typically between 2 and 12 cm (0.78740157480315 and 4.7 in). The margin (edge of the cap) is curled inwards, and when young is covered with a dense thicket of "hair" that withers in age to whitish fibers. Similarly, the cap surface is initially tomentose (covered with a thick matting of hairs) but eventually the hairs wear off, leaving the surface smooth. The surface is sticky to viscid and smooth on the central portion in early stages, often with whitish concentric zones. The overall cap color is pinkish-orange to pale dull pink, becoming orange to whitish on the margin, with the pink gradually fading. The white to flesh-colored 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....
is firm, but becomes flaccid in age. The latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
that is produced when the mushroom tissue in cut or injured is white to cream, and does not change color with prolonged exposure to air, nor does it stain the gills. It has an acrid taste, with a slight to pungent odor.
The gills are short-decurrent (running a little ways down the length of the stem), close to crowded together, narrow, and are sometimes forked near the stem. Their colour is whitish, becoming pale vinaceous (the colour of red wine) to pale orange or cream tinged vinaceous, turning pale tan with age. 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 1.5 – long, 0.6 – thick, fragile, more or less equal in width throughout, cylindrical or narrowed at the base. The surface of the stem is dry, and either smooth to pruinose (with a very fine whitish powder on the surface). Its colour is pale light pinkish to yellowish tinged or slightly pinkish orange to orange white, sometimes spotted. The flesh of the stem is firm, beige white, and stuffed (as if filled with cotton), but it eventually becomes hollow.
Microscopic characteristics
The spore printSpore 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...
of L. torminosus is cream to pale yellow. The spores are 8–10.2 by 5.8–6.6 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...
, roughly spherical to broadly elliptic in side view, and hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
(translucent). The ornamentation on the surface of the spores is 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...
, partially reticulate, with interrupted ridges and a few isolated warts. The prominences are roughly 0.5–0.7 μm high, with a prominent apiculus. The basidia (spore-bearing cells) are 30–47.7 by 7.3–8.2 μm, four-spored, club-shaped to cylindrical, and hyaline. The pleurocystidia are only present in the form of macrocystidia (very long cystidia) embedded and originating 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...
and just below it, measuring 40.3–80.0 by 5.1–9.5 μm. The macrocystidia are abundant, spindle-shaped to ventricose (swollen on one side), gradually tapering in width, with granular hyaline contents. The cheilocystidia are 30–52 by 4.5–8.0 μm, also in the form of macrocystidia.
Varieties
Lactarius normandensis was described by Alexander H. SmithAlexander H. Smith
Alexander Hanchett Smith was an American mycologist known for his extensive contributions to the taxonomy and phylogeny of the higher fungi, especially the agarics.-Early life:...
in 1960 to account for the North American species closely resembling L. torminosus, but having instead latex which changed colour from white to yellow upon exposure, and which stained tissues and paper yellow. Hesler
Lexemuel Ray Hesler
-External links:* Finding Aid for the Lexemuel Ray Hesler Collection, 1899-1982...
and Smith reduced this taxon to the status of variety in 1979. Lactarius torminosus var. normandensis has been collected from Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
and Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
in the United States, from 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....
in Canada, and from Switzerland. The variety resembles Lactarius pubescens
Lactarius pubescens
Lactarius pubescens, commonly known as the downy milk cap, is a species of fungus in the Russulaceae family. It is a medium to large agaric with a creamy-buff, hairy cap, whitish gills and short stout stem...
var. betulae, but differs in its longer pleurocystidia, larger spores with slightly different spore ornamentation, and its strongly burning acrid taste. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen, collected by Smith near Nordman, Idaho
Nordman, Idaho
Nordman is an unincorporated community in Bonner County, Idaho, United States. Nordman is located near Idaho State Highway 57 north of Priest River. Nordman has a post office with ZIP code 83848....
in 1956, is kept in the fungus collection at the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
Herbarium.
Edibility and toxicity
The intensely peppery taste of the raw mushroom can blister the tongue if sampled in sufficient quantity. Some authors have reported the species as poisonous, or causing "mild to fatal gastroenteritis". In a 1930 publication, Hans Steidle reported that although the mushroom was not toxic to "unicellular and cold-blooded organisms", the liquid extract and the pressed juice of the fruit bodies, when injected under the skin of a frog, resulted in disturbed breathing, paralysis, and eventually death. Despite these reports, in FinlandFinland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and other North European countries it is eaten, after boiling or five-day soaking, pickled and valued for its hot, burning taste. In Norway it is roasted, and added to coffee. The nutritive composition of the fruit bodies of Finnish specimens has been analysed and found to contain the following components (as a percentage of dry weight
Dry matter
The dry matter is a measurement of the mass of something when completely dried.The dry matter of plant and animal material would be its solids, i.e. all its constituents excluding water. The dry matter of food would include carbohydrates, fats, proteins, vitamins, minerals, and antioxidants...
): 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...
, 17.2%; phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
, 0.46%; calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
, 0.12%; magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
, 0.088%; potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
, 2.97%; sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
0.011%.
Similar species
Lactarius torminosulus is a dwarf version of L. torminosus, an arctic species associated with Betula nana or B. glandulosa. Immature fruit bodies of L. scrobiculatusLactarius scrobiculatus
Lactarius scrobiculatus is a basidiomycete fungus, belonging to the genus Lactarius, whose members are called "milk caps." Taxonomy places this species into subgenus Piperites, section Zonarii, subsection Scrobiculati....
resemble L. torminosus, but they have a white latex that soon changes yellow upon exposure to air, and their stems have depressed shiny spots. The caps of the poorly known species L. cilicioides are zoned, and its spores are smaller. L. pubescens
Lactarius pubescens
Lactarius pubescens, commonly known as the downy milk cap, is a species of fungus in the Russulaceae family. It is a medium to large agaric with a creamy-buff, hairy cap, whitish gills and short stout stem...
is physically quite similar, but can be distinguished by its paler colour and smaller spores (6–8.5 by 5–6.5 μm). L. controversus
Lactarius controversus
Lactarius controversus is a large funnel-capped fungus within the genus Lactarius, which are collectively known as 'milk caps'. They all exude milky drops from the flesh and gills when damaged...
has a cap margin that is not as hairy, whitish to cream-coloured gills, and larger spores measuring 7.5–10 by 6–7.5 μm.
Ecology, distribution, and habitat
Lactarius torminosus is a mycorrhizal species, and it plays an important role in nutrient and water uptake by trees. It grows in association with birch (Betula) and hemlock (TsugaTsuga
Tsuga is a genus of conifers in the family Pinaceae. The common name hemlock is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock....
) in mixed forests. It is also known to grow in urban settings where birch trees are nearby. Fruit bodies grow on the ground, scattered to grouped together. It is found throughout the United Kingdom, Northern Europe, and is common in North America, where it sometimes grows with aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
(Populus species). The North American distribution extends north into the Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
and Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, and south to Mexico.
The fruit bodies are a component of the diet of the red squirrel Sciurus vulgaris. Lactarius torminosus mushrooms may be parasitized by the mold Hypomyces lithuanicus.
Bioactive compounds
Lactarius torminosus contains the lactarane-type sesquiterpeneSesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be acyclic or contain rings, including many unique combinations...
lactone
Lactone
In chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...
15-hydroxyblennin A. This sesquiterpenoid has a lactarane skeleton
Skeletal formula
The skeletal formula of an organic compound is a shorthand representation of its molecular structure, developed by the organic chemist, Friedrich August Kekulé von Stradonitz. Skeletal formulae are ubiquitous in organic chemistry, because they are relatively quick and simple to draw. Carbon and...
, similar to compounds found in other Lactarius species, such as Lactarius deliciosus
Lactarius deliciosus
Lactarius deliciosus, commonly known as the Saffron milk cap, Red pine mushroom, is one of the best known members of the large milk-cap genus Lactarius in the order Russulales...
, Lactarius blennius
Lactarius blennius
Lactarius blennius is a medium-sized mushroom of the genus Lactarius found commonly in beech forests in Europe, where it is mycorrhizal, favouring the European Beech . It was first described by Elias Magnus Fries...
(blennin A), and Lactarius rufus
Lactarius rufus
Lactarius rufus is a common, medium sized member of the Lactarius genus, whose many members are commonly known as milkcaps. Known by the common name of the Rufous Milkcap, or the Red Hot Milk Cap in North America...
(lactarorufin N, deoxydihydroketolactarorufin N). Fruit bodies contain a number of sterol
Sterol
Sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol...
s, of which ergosterol
Ergosterol
Ergosterol is a sterol found in fungi, and named for ergot, a common name for the members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol does not occur in plant or animal cells...
is the predominant component at 60.5% (of total sterols), followed by the ergosterol derivatives ergost-7-en-3-ol (13.7%), ergosta-7-22-dien-3-ol (8.3%), and ergosta-5/7-dien-3-ol (17.0%). The mushrooms also contain the compound velleral, a breakdown
Chemical decomposition
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...
product of stearyl-velutinal, which is contained within the lactifers—specialized hyphal cells that produced the mushroom's latex. It has been suggested that broken lactifers leak precursors whose breakdown products act as defensive agents toxic to humans and effectively deter certain vertebrates that might consume the mushroom. Velleral, which has an extremely pungent taste and is thought to be responsible for the toxicity of the raw mushroom, is present at a concentration of 0.16 mg/g mushroom.