Cortinarius nolaneiformis

Pileus 15–55 mm, conical to hemispherical, then convex, often umbonate, margin slightly striate, even, later undulate, smooth, glossy, strongly hygrophanous, dark greyish brown to dark brown, pale yellowish to ochraceous brown when dry, margin blackish brown when old.
Lamellae medium spaced to fairly distant, emarginate, moderately broad, edge whitish when young, often uneven, brown to dark brown.
Stipe 25–75mm long, 5–10mm thick at apex, 5–7 mm thick at base, cylindrical to clavate, sometimes tapering downwards, white fibrillose when young, later with brownish longitudinal streaks, pale (ochraceous) brown when dry, cortina very sparse. Universal veil yellowish, very sparse.
Context occasionally hollow, uniformly brown when moist, greyish-whitish in pileus and most of the stipe when dry, brown at base.
Basal mycelium whitish to more distinctly yellowish (difficult to observe).
Odour distinct, somewhat reminiscent of cucumber or of other raw vegetables, slightly raphanoid.
Exsiccata: pileus very dark grey, very dark greyish brown, very dark brown to black, stipe dark greyish brown to very dark greyish brown, base of stipe (basal mycelium?) yellow (2.5Y 8/8).
UV observations: positive, lower part and the base of stipe strong yellow, pileus, lamellae and context dull yellowish brown.
Spores 7.5–9(9.3)×4.5–5.5 μm, Q=1.5–1.9, av. 8.1–8.6× 4.8–5.1 μm, Q(av.)=1.62–1.72, amygdaloid, occasionally ovoid to weakly ellipsoid, somewhat thick-walled, moderately to fairly strongly verrucose, moderately to fairly weakly dextrinoid.
Basidia 4-spored, 22–36×6–10.5 μm, clavate, pale olivaceous in MLZ. Lamellar edge fertile, with scattered to numerous, clavate sterile cells, pale olivaceous in MLZ. Lamellar trama hyphae pale olivaceous, finely and densely encrusted.
Pileipellis duplex, in overall view brown to yellowish brown, epicutis thin to moderately thick, hyphae 3–8 μm wide, hyaline or with brownish yellow content, smooth or slightly encrusted.
Hypoderm with distinct, 10–20 μm wide, cylindrical to ellipsoid elements, with hyaline, smooth walls. Clamp connections present.
ITS-regions (including 5.8S region): Maximum pairwise distance of the sequences two substitutions and indel positions. Cortinarius nolaneiformis differs from C. colymbadinus by 21 substitutions and indel positions and from C. uraceomajalis by 22 substitutions and indel positions.
Ecology and distribution: According to our present knowledge C. nolaneiformis grows both with coniferous (Picea) and several deciduous trees, especially with Fagus, but also with Quercus, Carpinus and Corylus, on rich to calcareous soils. The type collection of this species was found in Quercus forest, but some ITS identical collections from Europe and Iran have been collected in conifer mixed Fagus forests or other types of mixed forests. Cortinarius nolaneiformis seems to be widespread, but overlooked and most likely confused with C. uraceomajalis.