Name: Tricholoma equestre
Author: (L.) P. Kumm.
Citation: Führ. Pilzk. (Zerbst): 130 (1871)
Deprecated Synonyms: Tricholoma flavovirens (Pers.) S. Lundell
by Michael Kuo
This widely distributed species (or cluster of species, perhaps) can be recognized through a combination of features:White spore print, attached gills, medium stature, and other features that define the genus Tricholoma (see the key to Pale-Spored Gilled Mushrooms if you are unsure). Lack of a partial veil. Growth under conifers. A bright yellow cap that becomes brownish with age and lacks prominent blackish appressed fibrils. Mealy or mild taste. Yellow gills and stem.
A bit of a long list, I admit, but all the features should be matched before calling your find Tricholoma equestre (also known as Tricholoma flavovirens), since there are many similar species.
Ecology: Mycorrhizal with conifers—especially pines (species of Pinus), but a small form is also documented with spruces and firs; occasionally reported with madrone and with quaking aspen (but both of these trees often grow in the vicinity of conifers, or as pioneers in areas where conifers were recently logged); growing scattered or gregariously; widely distributed in North America; fall and winter.
Cap: 3-12 cm; broadly convex or nearly flat; sticky when fresh, but often dry; bright yellow when young and fresh, often with an olive brown or brownish center; becoming yellow-brown by maturity; smooth or with a few appressed fibers over the center, (but not prominently overlaid with blackish radiating fibers); the margin initially rolled under somewhat.
Gills: Attached to the stem, often by means of a notch; close; pale to bright yellow.
Stem: 2-10 cm long; up to 2 cm thick; more or less equal, or with an enlarged base; smooth or very finely hairy; pale yellow or whitish near the apex, yellow below; often discoloring yellow-brown, especially near the base.
Flesh: White to very pale yellow near the cap surface; not changing on exposure.
Odor and Taste: Taste mealy or not distinctive; odor mealy or not distinctive.
Spore Print: White.
Chemical Reactions: KOH on cap surface reddish (at least for spruce-fir-associated collections) or negative.
Microscopic Features: Spores 5-8.5 × 3-6 µ; smooth; elliptical; inamyloid. Cystidia absent. Clamp connections absent.
REFERENCES: (Linnaeus, 1753) Kummer, 1871. (Quélet, 1886; Saccardo, 1887; Kauffman, 1918; Smith, Smith & Weber, 1979; Ovrebo, 1980; Weber & Smith, 1985; Arora, 1986; Breitenbach & Kränzlin, 1991; Phillips, 1991/2005; Lincoff, 1992; Shanks, 1996; Evenson, 1997; Barron, 1999; Bedry and Others, 2001; Lassøe & Lincoff, 2002; Roody, 2003; Deng & Yao, 2005; McNeil, 2006.) Herb. Kuo 09010605, 09140804.
Tricholoma flavovirens is the name used by most North American field guide authors. However, Deng & Yao (2005) have officially synonymized Tricholoma flavovirens with Tricholoma equestre, with the latter name prioritized.
Small, slender forms of Tricholoma equestre are regularly collected under spruces and firs. I have collected such forms under Engelmann spruce and subalpine fir in the Rocky Mountains, but they should also be expected under balsam fir in northeastern North America. The more robust forms may be limited to association with true pines (species of Pinus, with bundled needles).
Further Online Information:
Tricholoma flavovriens at MykoWeb
Tricholoma flavovriens at Roger’s Mushrooms
Tricholoma equestre at Fungi of Poland
Created: 2007-06-19 16:53:03 AEST (+1000) by Nathan Wilson (nathan)
Last modified: 2018-11-28 15:43:36 AEDT (+1100) by Joseph D. Cohen (Joe Cohen)
Viewed: 761 times, last viewed: 2019-03-07 04:59:40 AEDT (+1100)