It is no dream!
Matsutake are growing On the belly of the mountain

When I first began my journey into mushroom identification, various genera stumped me time and again. But none were trickier for me than the various species of Tricholoma. White spores, central fleshy stipe, gills adnexed-to- sinuate and no ring or volva, I would repeat to myself. Of course, over the years, they became much easier to spot, but I am still stumped at times. There  are over 100 species in North America, many of them inedible, or downright poisonous.

Tricholoma is from the Greek, meaning “with hair on the edge or lump,” helping confuse one further. The largest specimen of Tricholoma in the world is found an hour or so northeast of my home in the town of Vilna, Alberta. Weighing more than 17,000 pounds and standing nearly twenty feet high, the “Burnt Tricholoma” sculpture was built in 1993. Its namesake (Tricholoma ustale) is a mushroom   that’s no more edible than the sculpture. Though this mushroom has an odor of anise or licorice, ingestion results in a gastric irritant containing ustalic acid.

My first firm identification of an edible member of the genus was Tricholoma flavovirens, also known as Man on Horseback. It has bright yellow gills and stipe, and when found in mossy areas is   a choice consumable. Or so I thought. Soon after enjoying my first meal, there was news out of Europe that the same or similar T. equestre may be poisonous and fatal. One Polish study tracked all T. equestre patients admitted to poison centers in Gdansk and Biala Podlaska between 2001 and 2010 (Sein and Chwaluk, 2010).

A mortality rate of 20% was observed, and included acute respiratory failure, myocarditis with arrhythmia and cardiovascular collapse. Known as rhabdomyolysis, the condition can progress to kidney failure and death. After consuming 100-400 grams of mushrooms for three to four days, four patients developed fatigue, muscle weakness, myalgia and in two cases, respiratory failure. One patient, aged 72 years, died on the second day of hospitalization. In others, the symptoms disappeared in two or three weeks (Anand et al., 2009). Various authors suggest the European and North American species are not   the same. Deng and Yao (2005) suggest the correct name for T. flavovirens is T. equestre. And just to add to confusion, Massart (2003) refer to the species by the synonym T. auratum, suggesting a morphologically similar species may be the culprit.

But the news of Man on Horseback is not all bad. Many mushrooms possess anti-bacterial activity and Man on Horseback is no exception, with strong activity against Bacillus subtilis. Weaker activity against E. coli, Staphylococcus aureus, S. epidermidis, and Pseudomonas aeruginosa was noted (Yamac and Bilgili, 2006). A mice study with freshly frozen (not cooked) mushrooms found myo-, cardio- and hepatoxic effects (Nieminen et al., 2008). An interesting compound, flavomannin-6,6’di-methyl ether, has been found, in vitro, to inhibit growth of human adenocarcinoma colorectal cancer cell lines (Pachón-Peña et al., 2009). Work by Hata et al., (2002) found a sterol in this mushroom that stimulates the enzyme alkaline phosphatase in mouse osteoblasts. High levels of this enzyme are associated with increased proliferation and differentiation of osteoblasts and prevention of osteoporosis. 

One of my favorite mushrooms is the Pine Mushroom (T. magnivelare) formerly known as Armillaria ponderosa. Also known as American Matsutake, this is a widely prized, commercial  mushroom  found throughout North America but most abundant in the Pacific Northwest. “Magnivelare” is from the Latin, meaning “with big veil.” Tom Volk suggests the taste is “an incredible and complex flavor you won’t ever forget—even though you won’t be able to adequately describe it to anyone.” David Arora (of Mushrooms Demystified) describes the odor as “a provocative compromise between ‘red hots’ and dirty socks.” Indeed the cinnamon and slight valerian/garden cress scent combined with firm texture lends itself to delicious thin slices toasted on the barbeque, or added to miso soup. This fall, I attended the Fungi Festival in Sicamous, British Columbia, and although it was unseasonably dry, I picked many Pine Mushrooms, along with lots of White Chanterelles (Cantharellus subalbidus) and numerous Lobster mushrooms (Hypomyces lactifluorum). The Thompson or Ntlakyapamuk people of southern British Columbia know this mushroom well. They call it /q’ám’es, as well as wood or mountain mushroom.

It was said that eating them raw would cut your tongue. Dried specimens were later added to soups and stews. Work by Nancy Turner and others (1990) recorded that a woman was named /q’é[- q’a]m’∂s after the pine mushroom. She was washed in a broth as an infant to make her strong. In turn, Turner’s own daughter was given this name, because she was washed in the juice from a jar of the mushroom a Thompson woman had given her. Of course, there is controversy over this mushroom as well, taxonomically speaking. The mushroom in northeastern North America, in many mycologists' opinion, should be changed to Tricholoma nauseosum, the European matsutake, which Bergius and Danell (2000) have found genetically identical to T. matsutake from Asia. A more recent study suggests this matsutake corresponds to the species in northeastern North America, and that T. matsutake may be the ultimate name for both (Chapela and Garbelotto, 2004). Confused yet?

A choice edible, St. George’s Mushroom is known to the Thompson people as thunderstorm, (s)/kí?[-ki?x, or thunderstorm head. It is known as Tricholoma gambosa or Calocybe gambosa. The common name is derived from England, where it pops out of the ground around the time of St. George’s Day (April 23). The name "Thunderstorm" is interesting, as cultures around the world have long associated mushrooms with thunder  and lightning. It was believed the vibration or sound triggered mushrooms appearing from nowhere. The beating of oak logs in a drumming manner was long practiced in Japan with shiitake cultivation. The rain accompanying these heavenly displays of force is the more probable science based source of fruiting. In China, the dried mushroom is used as a tea to treat measles and sick children feeling agitated and upset. Inhibition rates against both sarcoma 180 and Ehrlich carcinoma are 90% (Ohtsuka et al., 1973).

Another popular mushroom of the Thompson is /m∂λqi? (meaqi), also known as The Sandy, or Cottonwood Mushroom (T. populinum). The neighboring Shuswap call it semtl’ aka, the Okanagan-Colville, petl’kin, and the Lillooet, meix qin. It grows in sandy soil beneath large cottonwood trees and has a sweet, mealy scent like sweet bedstraw (Galium species) or cucumber. Both the Sandy and Thunderstorm are widely picked, dried and stored for winter. Formerly, the fruiting bodies were strung on strings and hung to dry. Some people freeze them, but others prefer to can various Tricholoma species because they are not as tough. The Shingled Trich (T. imbricatum) is a very common species found under conifers. It has a dry, dull brown cap with a solid stem; firm, white flesh and a faintly farinaceous scent. Studies have found high levels of antioxidant activity in the fruiting body based on five complementary free radical scavenging tests. More exciting was  the moderate inhibition activity  against both acetylcholinesterase and butyrylcholinesterase enzymes (Gülsen et al., 2012). This suggests possible use in the treatment of Alzheimer’s or Parkinson’s disease.


Tricholoma magnivelare. Courtesy of R. Rogers.

Streaked Tricholoma (T. portentosum) is also found under pine, and has gills and stalk tinged with greenish-yellow. It is commonly found around the world, and known in Japan as shimo-furishimeji, in Poland as siwki, and in Sweden, streckmusseron. It is a choice edible with a strong earthy flavor, but care must be taken in identification. The poisonous T. pardinum and T. virgatum are similar in appearance, so care is advised. Another inedible, probably poisonous, species is the Soapy Tricholoma (T. saponaceum). David Arora notes that a fairly infallible feature is the pinkish- orange color of the flesh at or near the base. It lacks the fibrillose scales of T. virgatum and T. pardinum mentioned above. During the 1950s and 60s in Switzerland, Tricholoma poisonings accounted for 20-50% of all reported intoxications, with Tiger Trich (T. pardinum) most notable. Soapy Trich is quite abundant in the Rocky Mountains just west of my home. Lab work has led to the discovery of two strong fibrinolytic enzymes in the fruiting body. The activity is via direct cleavage of fibrin clotting and not as a plasminogen activator (Kim and Kim, 2001).


Tricholoma terreum. Courtesy of M. Prosser.

Many members of genus Tricholoma, contain tricholomic acid, a flavor enhancer that excites brain neurons. In large doses, it is lethal to flies. Jonathan Ott, in his wonderful book, Pharmacotheon, writes a “single fly even squeezed through the tiny opening of the screw-cap vial in which the small amount of tricholomic acid solution was kept, and there met his death!” Ott detected tricholomic acid in Pleurotus species, and stated it’s “probably that it occurs in the shiitake.” Tricholomic acid is a likely candidate for the neurotoxin used by the Oyster mushroom to immobilize nematodes. The structural analog, glutamic acid, in the form of monosodium glutamate is a neurotoxin, associated with headaches, numbness, tingling, dizziness, nausea and other uncomfortable symptoms, especially in people deficient in B6. The book Excitotoxins by Russel L. Blaylock is a thorough exposé of this widespread additive, disguised on food labels with names like hydrolyzed yeast or protein, seasonings, broth, protein isolate or twenty other names that are permitted by the FDA. Due to possible damage to immature brain tissue, it was removed from baby food in 1970.

The Tricholoma genus, as you can see, is full of tricks and treats!

References Cited
Anand, J.S., P. Chwaluk, and M. Sut. 2009. Acute poisoning with Tricholoma equestre. Przeglad Lekarski 66(6):
Bergius, N., and E. Danell. 2000.  The Swedish matsutake (Tricholoma nauseosum syn. T. matsutake)
distribution, abundance and ecology. Scandinavian Journal of Forest Research 15(3): 318-325.
Chapela, I.H., and M. Garbelotto. 2004. Phylogeography and evolution in matsutake and close allies inferred by analyses of ITS sequences and AFLPs. Mycologia 96(4): 730-741.
Deng, H., and Y.J. Yao. 2005. Tricholoma equestre, the correct name for T. flavovirens (Agaricales). Mycotaxon
94: 325-329.
Gülsen, T., A. Müjde, E.D. Mehmet, and M. Öztürk. 2012. Antioxidant and cholinesterase inhibition activities of three Tricholoma species with total phenolic and flavonoid contents: the edible mushrooms from Anatolia. Food Analytical Methods 5(3): 495-504.
Hata, K., F. Sugawara, N. Ohisa, S. Takahashi, and K. Hori. Stimulative effects of (22E, 24R)-ergosta-7,22-diene- 3β, 5α,6 β -triol from fruiting bodies of Tricholoma auratum. Biological and Pharmaceutical Bulletin 25(8): 1040-4.
Kim, J.H., and Y.S. Kim. 2001.
Characterization of a metalloenzyme from a wild mushroom, Tricholoma saponaceum. Bioscience, Biotechnology, Biochemistry 65: 356-362.
Massart, F. 2003. The golden tricholoma (T. auratum [Fr.] Gillet) stands accused. Documents Mycologiques 32(126): 17-20.
Nieminen, P., V. Kärjä, and A.M. Mustonen. 2008. Indications of hepatic and cardiac toxicity caused by sub-chronic Tricholoma flavovirens consumption. Food and Chemical Toxicology 46(2): 781-86.
Ohtsuka, S., et al. 1973. Polysaccharides having an anticarcinogenic effect and a method of producing them from species of Basidiomycetes. US Patent 1331513. Issued: September 26, 1973.
Pachón-Peña, G., F.J. Reyes-Zurita, G. Deffieux, A. Azqueta, J.J. de Cerain,
E.E. Creppy, and M. Cascante. 2009. Antiproliferative effect of flavomannin- 6,6’dimethyl ether from Tricholoma equestre on Caco-2 cells. Toxicology 264(3): 192-197.
Sein, A.J., and P. Chwaluk. 2010. Acute intoxication with Tricholoma equestre— clinical course. Przeglad Lekarski 67(8): 618-619.

re-printed with permission from Winter 2012 • Volume 5:5 • FUNGI 35


Member Login
Welcome, (First Name)!

Forgot? Show
Log In
Enter Member Area
My Profile Not a member? Sign up. Log Out