Tricholoma saponaceum

Tricholoma saponaceum
Conservation status
Secure  (NatureServe) [1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Tricholomataceae
Genus:	Tricholoma
Species:	T. saponaceum
Binomial name
Tricholoma saponaceum (Fr.) P.Kumm. (1871)
Synonyms
Agaricus saponaceusFr. (1818) Tricholoma atrovirens(Pers.) Sacc. (1887)

Tricholoma saponaceum Mycological characteristics
	Gills on hymenium
	Cap is convex
	Hymenium is adnexed
	Stipe is bare
	Spore print is white
	Ecology is mycorrhizal
	Edibility is poisonous

Tricholoma saponaceum, also known as the soap-scented toadstool, soapy tricholoma, ^[2] soapy knight or soap tricholoma is an inedible mushroom found in woodlands in Europe and North America.

Taxonomy

Tricholoma saponaceum was first described in 1818 by seminal mycologist Elias Magnus Fries and given the name Agaricus saponaceus, before being placed in the genus Tricholoma by German mycologist Paul Kummer in 1871. The specific epithet saponaceum is derived from the Latin 'of or pertaining to soap'. ^[3] Its names in other European languages, such as French Tricolome à odeur de savon, and German Seifenritterling have a similar derivation to its English names-soap-scented toadstool, soapy knight or soap tricholoma—all relating to its soapy scent. ^{[2] [4]}

Tricholoma saponaceum is yet another fungus which may represent a species complex of two or more species. The variety ardosiacum, described by Italian mycologist Giacomo Bresadola, has a dark blue-grey cap.

Description

Tricholoma saponaceum has a convex cap about 4–15 cm (1.6–5.9 in) across, with a vague umbo ^[5] which flattens with age. The colour is highly variable, with greyish, greenish, olive, yellowish and brownish shades reported. The cap is paler at the margin and fades with age. The widely spaced gills are adnexed and whitish, although may be tinted pale green and bruise pink. The whitish stipe (also sometimes displaying colors present in the cap) lacks a ring and can be swollen in its midriff, and measures 4–12 cm (1.6–4.7 in) tall by 1–3 cm (0.4–1.2 in) wide. ^[5]

The flesh can but does not always stain pink-orange, and this color may already be present in the flesh of the stipe's base. ^[6] The spore print is white, and the oval smooth spores measure 5–6 × 3–4  μm. ^[2] The odour is distinctive and has been likened to newly scrubbed floors or soap. ^[4]

Similar species

Its gills may lead it to being confused with Hygrophorus species. ^[2] It is similar in appearance to Tricholoma griseoviolaceum . ^[5]

Distribution and habitat

Tricholoma saponaceum is a terrestrial mushroom found in Europe and North America. It is abundant in the Pacific Northwest and Rocky Mountains. ^[2] It is found in coniferous and deciduous woodlands (more commonly the former in North America) from late summer to late autumn. Spruce, live oak, tanoak, and madrone are species it can be associated with in the western United States. ^[2] It is associated with oak in Central and southern Europe. ^[4]

Toxicity

Bland or mild tasting, the fungus is usually classified as inedible or poisonous in guidebooks. ^{[2] [4] [7]} It contains toxins which can cause severe gastric upset. ^[8]

See also

• Hygrocybe
• List of North American Tricholoma
• List of Tricholoma species

References

1. NatureServe. "Tricholoma saponaceum". NatureServe Explorer. Arlington, Virginia. Retrieved 24 May 2025.
2. Arora, David (1986) [1979]. Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi (2nd ed.). Berkeley, CA: Ten Speed Press. p. 184. ISBN   978-0-89815-170-1.
3. Simpson DP (1979). Cassell's Latin Dictionary (5 ed.). London: Cassell Ltd. p. 883. ISBN   0-304-52257-0.
4. Nilson, Sven; Olle Persson (1977). Fungi of Northern Europe 2: Gill-Fungi. Penguin. p. 30. ISBN   0-14-063006-6.
5. Davis, R. Michael; Sommer, Robert; Menge, John A. (2012). Field Guide to Mushrooms of Western North America. Berkeley: University of California Press. pp. 166–167. ISBN   978-0-520-95360-4. OCLC   797915861.
6. Trudell, Steve; Ammirati, Joe (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. p. 106. ISBN   978-0-88192-935-5.
7. Phillips, Roger (2010). Mushrooms and Other Fungi of North America. Buffalo, NY: Firefly Books. p. 50. ISBN   978-1-55407-651-2.
8. Miller Jr., Orson K.; Miller, Hope H. (2006). North American Mushrooms: A Field Guide to Edible and Inedible Fungi. Guilford, CN: FalconGuide. p. 124. ISBN   978-0-7627-3109-1.