Tricholoma equestre
Encyclopedia
Tricholoma equestre or Tricholoma flavovirens, also known as Man on horseback or Yellow knight is a formerly widely eaten but hazardous fungus
of the Tricholoma genus that forms ectomycorrhiza with pine trees.
Known as Grünling in German, gąska zielonka in Polish, and canari in French, it has been treasured as an edible mushroom worldwide and is especially abundant in France
. Although it is regarded as quite tasty, cases of poisoning
from eating T. equestre have been reported. Research has revealed it to have poisonous properties.
who officially described it in Volume Two of his Species Plantarum
in 1753, giving it the name Agaricus equestris, predating a description of Agaricus flavovirens by Persoon
in 1793. Thus this specific name meaning "of or pertaining to horses" in Latin
takes precedence over Tricholoma flavovirens, the other scientific name by which this mushroom has been known. It was placed in the genus Tricholoma by German Paul Kummer
in his 1871 work Der Führer in die Pilzkunde. The generic name derives from the Greek
trichos/τριχος 'hair' and loma/λωμα 'hem', 'fringe' or 'border'.
The species may be in need of further analysis given the conflicting reports of toxicity.
Common names include the man-on-horseback, yellow knight, and saddle-shaped tricholoma.
. The gills are also yellow colour and the spores are white. The cap is usually a yellow to yellow-green sometimes with a touch of brown to brown-reddish colour. The diameter
is usually from 5 to 12 centimetres in length. The skin layer covering the cap is sticky and can be peeled off.
It can easily be mistaken for a variety of other members of the Tricholoma genus, such as T. auratum, T. aestuans and T. sulphureum
.
) for the peasants.
Concern was first raised in southwestern France. People who have been poisoned have all had three or more meals containing T. equestre within the last two weeks prior to treatment. One to four days after their last meal containing the fungus, the patients reported weakness of the muscles, sometimes accompanied by pain. This weakness progressed for another three to four days accompanied by a feeling of stiffness and darkening of the urine
. Periods of nausea, sweating, reddening of the face were also registered, but there were no fevers.
As yet, there have been no reported cases of poisoning in North America, and there is speculation that the respective mushrooms may in fact be different species that are very similar in appearance.
There are reports where patients treated for T. equestre poisoning have died, likely as a result of the poisoning.
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...
of the Tricholoma genus that forms ectomycorrhiza with pine trees.
Known as Grünling in German, gąska zielonka in Polish, and canari in French, it has been treasured as an edible mushroom worldwide and is especially abundant in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. Although it is regarded as quite tasty, cases of poisoning
Mushroom poisoning
Mushroom poisoning refers to harmful effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight gastrointestinal discomfort to death. The toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells...
from eating T. equestre have been reported. Research has revealed it to have poisonous properties.
Taxonomy and naming
Tricholoma equestre was known to LinnaeusCarolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
who officially described it in Volume Two of his Species Plantarum
Species Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...
in 1753, giving it the name Agaricus equestris, predating a description of Agaricus flavovirens by Persoon
Christian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
in 1793. Thus this specific name meaning "of or pertaining to horses" in 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...
takes precedence over Tricholoma flavovirens, the other scientific name by which this mushroom has been known. It was placed in the genus Tricholoma by German Paul 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...
in his 1871 work Der Führer in die Pilzkunde. The generic name derives from the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
trichos/τριχος 'hair' and loma/λωμα 'hem', 'fringe' or 'border'.
The species may be in need of further analysis given the conflicting reports of toxicity.
Common names include the man-on-horseback, yellow knight, and saddle-shaped tricholoma.
Description
The stem is yellow, usually about 4 to 10 centimetres long with an even diameterDiameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. The gills are also yellow colour and the spores are white. The cap is usually a yellow to yellow-green sometimes with a touch of brown to brown-reddish colour. The diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
is usually from 5 to 12 centimetres in length. The skin layer covering the cap is sticky and can be peeled off.
It can easily be mistaken for a variety of other members of the Tricholoma genus, such as T. auratum, T. aestuans and T. sulphureum
Tricholoma sulphureum
Tricholoma sulphureum, also known as sulphur knight or gas agaric, is an inedible or mildly poisonous mushroom found in woodlands in Europe. It has a distinctive bright yellow colour and an unusual smell likened to coal gas...
.
Toxicity
This species was for a long time highly regarded as one of the tastier edible species, and sold in European markets; medieval French knights allegedly reserved this species for themselves, leaving the lowly bovine bolete (Suillus bovinusSuillus bovinus
Suillus bovinus, also known as the Jersey cow mushroom, is a pored mushroom of the genus Suillus in the Suillaceae family. It is an edible mushroom that often grows in a symbiosis with pine.-Description:...
) for the peasants.
Concern was first raised in southwestern France. People who have been poisoned have all had three or more meals containing T. equestre within the last two weeks prior to treatment. One to four days after their last meal containing the fungus, the patients reported weakness of the muscles, sometimes accompanied by pain. This weakness progressed for another three to four days accompanied by a feeling of stiffness and darkening of the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
. Periods of nausea, sweating, reddening of the face were also registered, but there were no fevers.
As yet, there have been no reported cases of poisoning in North America, and there is speculation that the respective mushrooms may in fact be different species that are very similar in appearance.
There are reports where patients treated for T. equestre poisoning have died, likely as a result of the poisoning.
External links
- Food for Thought: Mushrooming Concerns "Science News Online" article on T. flavovirens (T. equestre).
- Tricholoma equestre poisoning "About Health Canada" article on Tricholoma equestre poisoning.
- Recent Poisonings from Edible Mushrooms! A report on a few new kinds of mushroom poisoning.
- Tricholoma equestre by Robert Sasata, Healing-Mushrooms.net. A literature review of medicinal or bioactive compounds from this species.
- Riddarmusseronen kan vara giftig Swedish article on T. flavovirens and its toxicity.
- Matportalen: Matsoppen som ble giftsopp Norwegian article on T. equestre.
- Google Image Search Google image search for "Tricholoma flavovirens".