Summary:
Subgenus Cortinarius. Features include very deep violet color and a dry cap that is rough due to many small scales or tufted fibrils. The species that occurs in the Pacific Northwest may be a variety of Cortinarius violaceus (L.: Fr.) S.F. Gray but this is not entirely clear. In Europe, subsp. hercynicus (Pers.) Brandrud is distinguished from subsp. violaceus by habitat and spore shape. This species is fairly common in the Pacific Northwest.

Cap:
3.5-12(15)cm across, convex becoming broadly convex, broadly umbonate or flat; deep violet to nearly black, often with a metallic luster when old, margin often somewhat paler; "dry, densely covered with minute erect, tufted hairs or small scales, giving it a rough, somewhat velvety appearance", margin often fringed or ragged, (Arora), 5-9(12)cm across, (hemi-)spheric, then flat-convex, sometimes broadly umbonate; dark violet with a metallic shine when young, later somewhat paler bluish violet, often grayish black when old, (Brandrud for both subspecies)

Flesh:
thick; deep violet becoming grayish violet, (Arora), "violet, paler bluish in cap and base of stem", (Brandrud for both subspecies), violet with white mottling (Trudell)

Gills:
"adnate becoming adnexed or notched, fairly well-spaced"; "deep violet or colored like cap, then dusted with cinnamon-brown spores", (Arora), "moderately crowded, later rather distant"; "dark violet, then dark purplish brown", edges white-fringed, (Brandrud for both subspecies)

Stem:
6-18cm x 1-2.5cm thick at top, equal or more often thicker in lower part, solid, firm; deep violet; dry, fibrillose or woolly, (Arora), 6-12cm x 1-2cm, more or less strongly clavate-bulbose (up to 4cm wide), (grayish-)violet, basal mycelium bluish, (Brandrud for both subspecies), stem often darkens when handled (Trudell)

Veil:
cortina violet, soon disappearing or leaving a few indistinct hairs on stem, (Arora), veil grayish, fibrillose, forming indistinct girdles, (Brandrud for both subspecies)

Odor:
mild or cedar-like, (Arora), not distinctive (Phillips), "weak but distinct of cedar wood or leather" (Brandrud for both subspecies)

Taste:
not distinctive (Phillips), slightly peppery (Miller)

Microscopic spores:
spores 13-17 x 7-10 microns, broadly elliptic to oblong, rough; pleurocystidia and cheilocystidia present, (Arora), 11.5-13.5 x 7-8(8.5) microns, elliptic to almond-shaped, distinctly verrucose; cheilocystidia abundant, large, 60-95(110) x (12)15-25 microns, more or less lageniform, with blue, then often brown content, pleurocystidia fairly similar; cap cuticle with a thick epicutis (trichoderm) of more or less erect hyphae 10-15 microns wide, with blue, then brown vacuolar pigment, (Brandrud for subsp. violaceus), 11-13.5 x (7.5)8-9 microns (but further spore variation occurs in North America and southern hemisphere), broadly elliptic to almost subglobose, very distinctly verrucose, cystidia described the same way as for subsp. violaceus, (Brandrud for subsp. hercynicus), spores 11.5-14.5 x 7-8.5 microns, elliptic to almond-shaped, moderately verrucose, ocher-brown; basidia 4-spored, 40-60 x 13-16 microns, clavate, with basal clamp connection, pleurocystidia somewhat similar to cheilocystidia, fusiform to lageniform, cheilocystidia 47-80 x 15-25 microns, lageniform with long rostrum, with violet contents when fresh, with brown contents when dried; cap cuticle of periclinal to ascending hyphae with exserted ends 8-18 microns wide in fascicles, colorless to brown, some septa with clamp connections, (Breitenbach for subsp. violaceus), spores 11-14 x 8.3-10 microns, broadly elliptic, moderately verrucose, ocher-brown; basidia 4-spored, 33-48 x 12-15 microns, clavate, with basal clamp connection; pleurocystidia similar to cheilocystidia, cheilocystidia 50-80 x 15-23 microns, subulate to lageniform, with violet contents when fresh, with brown contents when dried; cap cuticle of periclinal to ascending hyphae with exserted ends 4-14 microns wide, colorless to brown, some septa with clamp connections, (Breitenbach for subsp. hercynicus)

Spore deposit:
rusty brown (Arora)

Notes:
C. violaceus is reported specifically from BC (in Redhead(5)), from WA (Jumpponen(1)), from OR (collections at Oregon State University), and from ID by Andrew Parker, pers. comm., from CA (Arora). It is also reported from Europe including Germany and Australia (Garnica(1)) and Switzerland (Breitenbach(5)).

EDIBILITY

edible but not choice (Arora)