Summary:
The principal fieldmarks are the orange to brown cap and stem, decurrent gills that are orange and dichotomously forked, and white spore deposit. It is common in the Pacific Northwest. Some authors consider Hygrophoropsis aurantiaca a member of Paxillaceae.

Cap:
2-8(14)cm across, convex becoming flat or somewhat depressed, margin at first inrolled; "typically some shade of dark orange, brownish-orange, brownish-yellow, yellowish-brown, olive-brown, or dark brown (often darker or browner at center and orange to yellowish-orange at margin), but in one form whitish and in another blackish"; "dry, often somewhat felty or velvety", (Arora), 2-9cm across, flat-convex, then depressed or subcyathiform [somewhat cup-shaped], margin involute [inrolled] at first; orange-ochraceous, becoming fuscous or fuliginous; villous to subtomentose, becoming bald, (Corner), dark orange-brown to dark olivaceous brown or blackish brown when young, disc "often remaining dark for some time, margin soon becoming brighter and orange", "fading with age and exposure, occasionally whitish from the first"; margin ribbed at times but not striate (Bigelow)

Flesh:
thin; "pallid or tinged orange or cap color", (Arora), thick in center of cap, cottony-floccose, soft; white to yellowish, (Corner)

Gills:
"decurrent, close, fairly thin and narrow at maturity (may be blunt when young)", usually forked dichotomously; "typically deep orange to bright orange, but sometimes pale orange or in one form yellowish", (Arora), decurrent, crowded, 24-34 primaries, 0.1-0.2cm wide, edge blunt, gills 3-5 times dichotomous, easily separable from cap; deep orange; often slightly veined on sides, (Corner), narrow to moderately broad (up to 0.5cm), thick in buttons, thin when old; orange and usually brighter than cap, (Bigelow)

Stem:
2-10cm x (0.2)0.5-1(2)cm, "central or off-center, equal or enlarged toward base, often curved"; "yellowish to orange or brownish-orange or colored more or less like cap"; dry, (Arora), 2-5cm x 0.3-0.9cm, subcylindric or widening downwards, fibrous soft; bister or ochraceous, fuliginous when old; subtomentose or subvillous, (Corner), stuffed becoming hollow; pale orange when young, darker when old and especially at base; bald or fibrillose-striate, (Bigelow)

Veil:
absent

Odor:
mild, mushroomy, (Phillips), mild (Arora)

Taste:
mushroomy (Phillips), unpleasant (Corner), mild (Bigelow)

Microscopic spores:
spores 5-8 x 2.5-4.5 microns, elliptic, smooth, often dextrinoid, (Arora), 5-8 x 3.5-5.5 microns, elliptic to subcylindric, smooth, wall slightly thickened, 1-2 droplets; basidia 4-spored, 28-40 x 8-11 microns, clavate; pleurocystidia and cheilocystidia none, (Corner), clamp connections mentioned for basidia and cap cuticle, (Breitenbach)

Spore deposit:
white to creamy (Arora), white (Miller)

Notes:
Collections were examined from BC, WA, OR, ID, and also NS, ON, QC, SK, AK, CA, MA, ME, MI, NC, NH, NM, NY, TN, Mexico, France, and United Kingdom, (Bigelow(6)). The distribution includes north temperate parts of the world and Australia.

EDIBILITY

avoid, as possibly poisonous according to some, (Arora), some reports hallucinogenic (Phillips)