Cortinarius violaceus
Description
Cortinarius violaceus is perhaps the most distinctive species in the genus. It has a dark violet, dry, scaly to tomentose cap with a somewhat metallic sheen. The close gills are deep violet and the stipe is typically broadly club-shaped, dry and violet, with a bluish color on the base at times, and a veil that appears somewhat grayish.
The flesh is violet with white mottling and the odor is distinct from cedarwood. Often the stipe base darkens when handled.
In Europe, two very similar species are recognized, C. violaceus in hardwood forests and C. hercynicus (Persoon) Brandrud in conifer forests. The latter has almond-shaped to ellipsoid spores that are narrower than those of the former.
The form occurring in western North America may well represent a separate species, but that is yet to be determined.
Common names: Violet Webcap, Violet Cort, Dunkelvioletter Schleierling (German).
Mushroom Identification
Ecology
Mycorrhizal with hardwoods or conifers; in western North America often reported as appearing in old-growth conifer forests near rotting logs; growing alone, scattered, or gregariously; fall; widely distributed in North America.
Cap
4–12 cm; convex, becoming broadly convex, nearly flat, or slightly bell-shaped; dry; densely hairy, becoming fuzzy or scaly; deep purple, becoming brownish-purple and eventually dark brown overall.
Gills
Attached to the stem; nearly distant; dark purple at first, becoming grayish to blackish, and eventually rusty brown; covered by a purple cortina when young.
Stem
6–16 cm long; up to 2 cm thick; equal above a swollen or club-shaped base; dry; purple and finely hairy when young, becoming purplish gray to nearly black or brown, with a sheen; dry; becoming hollow.
Flesh
Purple to lilac or purplish gray.
Odor
Sweet and slightly fragrant, or not distinctive.
Spore Print
Rusty brown.
History
Described scientifically in 1755 by Carl Linnaeus, who called it Agaricus violaceus, the Violet Webcap was transferred to the genus Cortinarius in 1821 by the British mycologist Samuel Frederick Gray (1766 - 1828).
Some authorities split Cortinarius violaceus into two varieties: Cortinarius violaceus var. violaceus, which is mycorrhizal with broadleaf trees, and Cortinarius violaceus var. hercynicus, which forms mycorrhizae with conifers. The former has almond-shaped spores while the latter is distinguished by its ellipsoidal spores.
Cortinarius violaceus is the type species of the genus Cortinarius, which is the largest of the mushroom genera. Being violet, this webcap's color is far from typical, as the majority of webcap species have fawn, orange or brown coloring. There are, however, other 'blue' webcaps including for example Cortinarius caerulescens.
It hardly needs mentioning that the common name Violet Webcap comes from the color of every part of this mushroom plus its web-like partial veil, or cortina, that spans the gap between stem and cap edge, thus covering the ripening fertile surfaces (the gills) of the mushroom. Similarly, the specific epithet violaceus is a direct reference to the color of these beautiful mushrooms.
Photo sources:
Photo 1 - Author: 2008-08-22_Cortinarius_violaceus_(L.)_Gray_18241.jpg: (CC BY-SA 3.0)
Photo 2 - Author: Holger Krisp (CC BY 3.0)
Photo 3 - Author: Jimmie Veitch (jimmiev) (CC BY-SA 3.0)
Photo 4 - Author: Jerzy Opioła (CC BY-SA 4.0)
