Summary:
Subgenus Phlegmacium. Cortinarius multiformis is characterized by a viscid cap that is strong brownish yellow to orange or orange brown; grayish white gills; a dry, white, relatively slender stem with a variably marginate bulb, that sometimes becomes equal; a weak smell of honey; growth under conifers, often in deep moss; and slightly rough spores. Note that Brandrud(5) et al. later (2014) circumscribed 10 European species in section Multiformes of subgenus Phlegmacium supported by molecular data and morphological species. They also provided a descriptions, photographs, and key to these species in Europe. These include Cortinarius multiformis, C. caesiolamellatus, C. pallidirimosus, C. rufoallutus, and C. talus. Cortinarius multiformis is abundant in some years in the Pacific Northwest.

Cap:
4-8cm across, (hemi-)spheric, then flat-convex; homogeneous (dark) ochraceous yellow to almost red-brown, with age often hygrophanous toward margin; viscid, (Brandrud), often with a bloom (J. Ammirati, pers. comm.)

Flesh:
white

Gills:
crowded; grayish white when young; often somewhat serrulate [finely toothed], (Brandrud(1)), adnate to adnexed or notched (Arora for C. multiformis), 0.4-0.8cm broad, crowded; "initially grayish white", (Brandrud(5))

Stem:
4-8cm x 1-1.5cm, with more or less marginate bulb (up to 2.5cm wide), but sometimes becoming equal; white but discolors brass brown with age; shiny, (Brandrud(1)), dry (Arora), 5-12(14)cm x 0.8-1.5cm, "usually slender, with a faintly to rather distinctly marginate-bulbous base", "often becoming quite non-marginate (almost cylindric)" when old; "white, turning distinctly brass-brown" when old; glossy, (Brandrud(5))

Veil:
white sparse fibrillose veil (Brandrud(1)), universal veil "near the bulb very sparse, whitish at bulb margin", (Brandrud(5))

Odor:
faint of honey when bruised, (Brandrud(1)), "none or faint of honey, at least in bulb when bruised", (Brandrud(5)), odorless to smelling faintly like honey, may be stronger in base of stem than in other parts of fruitbody, (Breitenbach)

Taste:
sweet (Lincoff(1))

Microscopic spores:
spores 8-9.5 x 5-5.5 microns, elliptic to amygdaliform [almond-shaped], slightly verrucose [finely warty]; gill edge fertile or with small clavate to cylindric cells; cap cuticle with a thin epicutis, hyphae 2-5(7) microns wide, colorless; hypodermium developed, hyphae 10-25(30) microns wide "with yellowish brown thick-wall pigment", (Brandrud(1)), |spores 8-9.5 x (4.5)5-5.5(6) microns, elliptic to subamygdaloid, "weakly to distinctly and rather densely to diffusely verrucose, warts irregular to slightly confluent, rounded", "sometimes warts very flat and hardly visible in the outline of the spores"; cap cuticle "duplex, at surface of thin, erect-entangled gelatinous", +/- colorless hyphae, subcutis/hypodermium "subcellular, hyphae tightly cemented, with yellow brown parietal-encrusting pigment, forming an amber-like embedment", thick, brown walls "especially pronounced in corners between the cells", forming irregular-triangular ''lenses'', to more diffuse lumps of brown pigments, more narrow, longer transition hyphae "between subcutis with and epicutis with yellow walls, and sometimes with zebra-striped encrustration", (Brandrud(5))

Spore deposit:
[presumably a shade of brown]

Notes:
It is found at least in WA (Cripps(6)) and AB (Kernaghan). A collection from BC deposited at Pacific Forestry Centre in 1997 was determined by J. Ammirati and S. Gamiet (as Cortinarius allutus, a name in use for this taxon at that time). Collections were sequenced from BC (Liimatainen). Two North American (Canadian) collections of C. multiformis differ by one nucleotide from the European neotype (Brandrud(5)). It is also documented by molecular methods from NL, Finland and (holotype) Sweden (Cripps(6)).

EDIBILITY

Synonyms and Alternate Names:
Cortinarius allutus sensu auct. (misapplied name)