Summary:
Subgenus Dermocybe. Features include 1) a dry, non-hygrophanous cap that is yellow brown, dark brown or red brown to deep red, with the surface appressed-fibrillose to fibrillose-scaly, 2) red gills, 3) a dry, silky-fibrillose stem that is light buff to yellowish or olive buff, with some yellowish to brownish veil fibrils, the base red orange to yellowish buff, 4) habitat under conifers, and 5) color as seen under UVL bright orange yellow stem surface and flesh, with bright yellow on parts of the stem base. This species has long been known in the Pacific Northwest as Cortinarius semisanguineus, but the true Cortinarius semisanguineus has not been documented from North America (Ammirati).

Cap:
1.5-5(7)cm across, conic - bell-shaped to rounded conic becoming convex to flat, umbonate to slightly umbonate, margin slightly inrolled at first becoming incurved to decurved [downcurved]; on disc yellow-brown or orange-brown or dark yellow-brown, on margin typically yellow-cinnamon to ochraceous brown or ochraceous buff, sometimes when young tinted orange-buff, when old tinted or streaked with colors of disc, occasionally the overall coloration tinted with light olive-brown; moist to dry, not hygrophanous, appressed-fibrillose to fibrillose-scaly, sometimes more or less rimose [cracked] on the disc

Flesh:
solid, firm; "dull whitish to light dull yellowish or slightly brownish, often becoming more or less sordid", in stem yellowish white to dull yellow or more or less colored as surface, developing a watery olivaceous cast when old, in some the cortex of the stem base has a reddish to reddish orange cast

Gills:
"adnate to adnexed, close to nearly crowded"; "red, dull red or brown orange"; edge +/- even "to slightly irregular", colored as faces or paler, (Ammirati), narrowly sinuate-emarginate, broad (0.5-0.8cm), moderately crowded; crimson, blood red, edge orange yellow, (Bidaud)

Stem:
2.5-8.0cm x 0.4-0.95cm above, base 0.7-1.5cm wide, "equal to clavate or ventricose", "stuffed becoming hollow"; "light buff to dull light buff, pale yellow, yellowish or olive buff, with some yellowish to brownish veil fibrils, base red orange to yellowish buff"; silky-fibrillose, (Ammirati), 4.0-7.0 x 0.5-0.8cm, subequal or slightly rounded at the base, slightly tortuous, hollow; hygrophanous, citrine yellow [Latin also mentions ochraceous orange], with incomplete bracelets of a gray-brown veil, sometimes in chevrons; salmon pink mycelium, (Bidaud)

Veil:
cortina yellowish (Ammirati)

Odor:
raphanoid [radish-like] to indistinctive, (Ammirati), raphanoid when cut and then of cedar wood (when enclosed in a box), (Bidaud),

Taste:
raphanoid [radish-like] to indistinctive, (Ammirati)

Microscopic spores:
spores 6-7(8) x 3.8-4.5 microns, "ellipsoid, verrucose"; basidia 4-spored; pileipellis hyphae "cylindrical to enlarged", 5-16 microns, "colorless, brownish, often filled with purple, blue purple  or vinaceous pigment" , (Ammirati) spores (6) 6.5-8(8.5) x 4.5-5.5 microns, ovoid, finely pitted; basidia 4-spored, 25-30 x 7-10 microns; marginal cystidia present, (Bidaud)

Notes:
"This a very widespread species", recorded from BC, WA, OR, ID, AB, AK, AZ, CA, FL, ME, MD, MA, MI, MS, NH, NY, OH, TN, TX, UT, and WY. It probably occurs in most states. (Ammirati). The holotype of Cortinarius ominosus is from France.

EDIBILITY

Synonyms and Alternate Names:
Cortinarius semisanguineus (Fr.) Gillet sensu auct. (misapplied name)
Dermocybe semisanguinea (Fr.) M.M. Moser