Summary:
Tricholoma equestre is characterized by a viscid, yellow or brown to reddish brown cap, sometimes olive yellow, yellow gills, a white to pale yellow stem, absent veil, a farinaceous or coconut odor, habitat under pines, and white spores. The name T. flavovirens is favored by some authorities (e.g. Bon(1) in 1976), and the name T. equestre is favored by others (e.g. the online Species Fungorum, accessed June 6, 2014, MycoBank accessed June 6, 2014, Riva as explained in Breitenbach, and Deng(1) in 2005 who noted also that Bon reversed himself in 1987). Deng(1) clarifies the point that T. flavovirens may be the correct name indicating the type of the genus, at the same time as T. equestre is the correct name for the species. Bon(1) separates T. auratum as a more robust species, thicker stemmed, 4-8(10)cm x 1-3cm versus 6-10cm x 0.8-1(1.5)cm, with a viscid cap versus dry and slightly viscid in wet weather for T. flavovirens, favoring sandy pine habitat whereas T. flavovirens is found under hardwoods or conifers. Riva on the other hand included T. auratum in the concept of T. equestre. Tricholoma equestre is common in the Pacific Northwest.

Cap:
4-15(20)cm across, convex becoming flat or with margin uplifted when old, margin inrolled at first; entirely yellow or brown to reddish brown toward center and yellow at margin, or sometimes olive-yellow; "viscid when moist, smooth"^, (Arora), 3.3-11cm, convex to broadly convex, a low broad umbo often present, margin becoming uplifted when old; golden yellow to pale yellow overall, or disc yellowish brown when young, becoming yellowish brown to brown overall when old from brown fibrils over a yellow background; viscid, appressed-fibrillose to minutely squamulose [fine-scaly] over the disc, bald elsewhere, (Shanks)

Flesh:
thick, firm; white^, (Arora), white in cap and stem, pale yellow near cap surface, (Shanks), thin; whitish, yellowish under cap surface, in stem whitish to lemon-yellow, (Breitenbach)

Gills:
notched or adnexed, close, broad; yellow, (Arora), sinuate to strongly notched, close, 1cm broad, thin; pale yellow to yellow, (Shanks)

Stem:
3-10cm x 1-3(4)cm, equal or slightly widened at either end, solid; "white to pale yellow or sometimes with darker stains at base"; dry, smooth , (Arora), 2-10.5cm x 0.8-2cm, equal or with slightly bulbous base, fibrous, solid or hollow; white to pale yellow at the top, pale yellow to yellow elsewhere, surface fibrils darkening to pale yellow brown when old; dry, innately fibrillose, (Shanks)

Veil:
absent (Arora)

Odor:
"farinaceous or somewhat like coconut", (Arora), not distinctive to mildly farinaceous, (Shanks)

Taste:
not distinctive to mildly farinaceous (Shanks)

Microscopic spores:
spores 6-8 x 4-5 microns, elliptic, smooth, [presumably inamyloid], (Arora), spores 4.8-8.6 x 3.4-5.8 microns, elliptic to broadly elliptic, smooth, inamyloid; basidia 4-spored, 31.2-43.2 x 7.2-9.6 microns, clavate, colorless or occasionally with granular brown contents; pleurocystidia and cheilocystidia absent; clamp connections absent, (Shanks)

Spore deposit:
white (Arora)

Notes:
It has been reported specifically for BC (in Redhead(5)), for WA by O''Dell(1), for CA by MykoWeb, and for MT by Cripps. There are collections at the University of British Columbia from BC, YT, PQ, and NB and at the University of Washington for WA, OR, ID, AK, MS, UT, VA, and WY. Bessette(5) say it is widely distributed in North America and show photographs from OR, ID, CO, FL and NY.

EDIBILITY

not recommended: there are reports of poisoning (in France, for instance) and species concepts are still not clear