Summary:
Subgenus Phlegmacium. Features include a glutinous, bright yellow cap that becomes orange-brown from the center, yellow gills that become brownish with an olivaceous tinge, a dry, whitish stem that becomes yellowish to brownish orange, a marginate bulb fringed by yellowish veil, growth under hardwoods, and almond-shaped to somewhat lemon-shaped spores.

Cap:
4-15cm across, convex with involute margin at first, later flat and finally depressed with wavy margin, but margin in old specimens remaining somewhat involute; bright yellow when young, later the margin remaining bright yellow or slightly darker and the center becoming fulvous, bright orange-brown, some areas tinted "Sanford's brown", "with age over most of the surface so, disc sometimes spotted, toward the margin sometimes with brown streaks but not innately fibrillose"; glutinous, (Moser), 5-15cm across, convex becoming flat, margin at first incurved; "entirely yellow or with only the margin yellow and the center fulvous to ochre to orange-brown, sometimes with small spotlike scales", surface viscid when moist, (Arora)

Flesh:
at first whitish in center, yellow near cap surface, pale yellowish in stem, later cream colored to very pale yellowish, (Moser), thick, firm; yellow to yellowish white or buff, (Arora)

Gills:
rounded adnate to emarginate, close, 120-140 reaching stem, 12-19 per centimeter at margin, 1-3 subgills between neighboring gills, gills 0.4-1.2cm broad, about half to one times thickness of cap flesh; at first yellow, later becoming brownish with an olivaceous tinge, gill edge sometimes brownish, edges uneven to serrulate, sometimes with darker brown spots [unclear whether spots apply to faces or edges], (Moser), adnate or notched, close; yellow to yellow-brown or ocher, becoming ocher-cinnamon and finally rusty brown, (Arora)

Stem:
3.5-11.5cm x 1.3-3.5cm at top, widening to obliquely marginate bulb 3-4.5cm, "in many specimens somewhat rooting below the rim, in some specimens only rounded"; whitish when young, "later more yellowish, brownish yellow to brownish orange, the bulb fringed by yellowish veil", when old discoloring reddish or orange brown, "bulb underneath whitish to reddish brown", (Moser), 3-7cm x 1-3cm at top, "often rather short and stout, with a large rimmed bulb at the base", solid, firm; yellowish white or yellow, sometimes becoming ochraceous when old; not viscid, (Arora)

Veil:
sulphur yellow, "later discoloring orange brown to reddish brown, in old specimens mostly disappearing", (Moser), cortina pallid or yellowish, often leaving hairs on stem that turn rusty brown from falling spores, (Arora)

Odor:
"weak, slightly of hot baked", (Moser), mild or radish-like, (Arora)

Taste:
mild, (Moser), mild or radish-like, (Arora)

Microscopic spores:
spores 8.2-10.6 x 4.9-6.0 microns, almond-shaped to sublimoniform [somewhat lemon-shaped], "verrucose, apex smooth, content reddish in 3% KOH"; basidia 4-spored, 32-34 x 7.5-9 microns, clavate, often with a brownish content, subhymenial hyphae 3-4(5) microns wide, trama hyphae 4-7 microns wide, in mediostratum 7-9(10) microns wide, +/- colorless under microscope, clamp connections present; no cheilocystidia, (Moser), spores 8-10 x 4.5-6 microns, elliptic, roughened, (Arora)

Spore deposit:
rusty brown (Arora)

Notes:
Cortinarius fulmineus was examined from Del Norte County in extreme northwestern CA (Moser(4)) and therefore likely to appear at least in Oregon. There are 2 collections by O. Ceska from BC at the University of British Columbia identified as this species.

EDIBILITY

unknown (Arora)