Cap 3.5-7.0 cm broad, obtuse-conic, becoming convex-umbonate to plane with a raised disc; margin at first incurved, appressed to the stipe, eventually decurved; surface when young, glabrous, slimy to glutinous in moist weather, dark-brown at the disc, the margin lighter, translucent-striate; in age cap fading to dull tan-brown, the margin then conspicuously wrinkled halfway to the disc; context up to 7.0 mm thick at the disc, thin elsewhere, whitish, firm, darkening slowly to buff-brown when cut; odor and taste mild.
Gills adnexed to notched with a decurrent tooth, close to subdistant, relatively broad, up to 6.0 mm wide, cream-buff when young, dull tan-brown in age, edges lighter than the faces; lamellulae three to four-seried.
Stipe 8.0-16.0 cm long, 1.0-1.5 cm thick, more or less equal or gradually narrowing towards the base, stuffed, the core narrow, pith-like; surface fibrillose to fibrillose-striate, apex whitish, the lower portion covered with a violet-purplish slime except for a sometimes whitish base; context fibrous, pallid, darkening slightly when cut; partial veil fugacious, frequently leaving no evidence of a ring or annular zone.
Spores 11.0-14.5 x 7.0-8.5 µm, ellipsoid to football-shaped in face-view, conspicuously inequilateral in side-view, roughened, relatively thick-walled, hilar appendage distinct; spore print dull-brown, not rusty-brown.
Solitary to gregarious in conifer woods; fairly common along the coast from Mendocino Co. northward; fruiting from early to late winter.
Cortinarius vanduzerensis is arguably one of the prettiest of California mushrooms; it is also one of the slimiest, defying all but the most sure-handed collector. This member of the subgenus Myxacium is recognized by a rich brown often umbonate, slimy cap with a wrinkled margin, dull tan gills, and violet-purple, slimy stipe. Cortinarius elatior is similar but has violet-tinged gills in youth while Cortinarius collinitis, has a lighter brown slimy cap, with glutinous bands on the stipe, the latter rarely tinged purple; A third species in this group, Cortinarius cylindripes, has a lighter colored, sometimes wrinkled cap, the gills pale purple when young with fringed edges.