Summary:
Tricholoma aurantium is distinguished by a viscid orange to orange-brown or red-brown or olive-splashed cap, rusty stained gills, a pallid stem with conspicuous belts of rusty orange scales up to a line near the apex of stem that suggests a rudimentary veil, and a strong farinaceous odor.

Cap:
4-10cm across, convex becoming obtusely umbonate or flat, margin inrolled when young; "yellow-orange to tawny, bright rusty-orange, orange-brown, orange-tan, or even orange-red, sometimes splashed with olive-green or in one form entirely deep olive-green when young"; "viscid when moist, smooth or breaking into small scales (especially at center)", "sometimes beaded with orange droplets when moist", (Arora), 3.5-10cm across, convex with inrolled margin becoming flat-convex when old; "orange, particularly at margin, to reddish brown, often with olive coloration over disc"; viscid, nearly bald, often with orange droplets at margin, (Shanks)

Flesh:
thick; white, (Arora), white in cap and stem, (Shanks)

Gills:
"adnate to adnexed or notched, close"; whitish, often developing rusty brown or reddish brown spots and stains, (Arora), sinuate, close to crowded, thin; "whitish, staining orange-brown", (Shanks)

Stem:
3-8cm x 0.8-2cm, equal or wider at either end, solid, firm; belted with rusty orange scales or scurfy flakes up to a well-defined line near top, pallid above this line; "in wet weather sometimes beaded with orange droplets near the line", (Arora), 4-8cm x 1-3cm, equal, solid; with belts of orange fine scales, the fine scales staining greenish in older fruitbodies, a faint ring zone present near top, which lacks the surface ornamentation of the rest of the stem, (Shanks)

Veil:
absent or very rudimentary (Arora), a faint ring zone near top of stem, (Shanks), veil present as a colored sheath on stem which terminates in a line but no actual veil tissue present to form a ring, only a line visible, (Smith)

Odor:
"strongly farinaceous and disagreeable (like rancid oil or cucumber)", (Arora), farinaceous, (Shanks), cucumber (Courtecuisse), "disagreeable, strong, as old meal or corn silk", (Miller)

Taste:
"strongly farinaceous and disagreeable (like rancid oil or cucumber)", (Arora), farinaceous, cap cuticle may be bitter, (Shanks), bitter (Courtecuisse)

Microscopic spores:
spores 4-6 x 3-5 microns, elliptic to nearly round, smooth, [presumably inamyloid], (Arora), spores 4.8-6 x 2.5-3.2 microns, elliptic, smooth, inamyloid, colorless; basidia 4-spored, 22-34 x 5-7 microns, clavate; cheilocystidia "absent or present as occasional filamentous hyphae" 3-4 microns wide extending beyond the margin; cap cuticle an ixocutis, hyphae 3.2-3 microns wide, colorless or with refractive orange-brown contents, smooth; clamp connections absent, (Shanks)

Spore deposit:
white (Arora)

Notes:
O''Dell reported it for WA. There are collections from BC at the University of British Columbia. The University of Washington has collections from WA, OR, AK, CO, MI, MT, and WY. It has been reported from ID by Andrew Parker, pers. comm. Bessette(5) says it is widely distributed in North America and shows photographs from CO and WV.

EDIBILITY

unpalatable (Arora)