What You Should Know
Cortinarius glaucopus is a basidiomycete mushroom of the genus Cortinarius native to Europe and North America.
Cortinarius glaucopus represents a complex of closely related species in California, as evidenced by the variable pigmentation of the cap margin, gills, and stipe, which typically include violet, blue, or olive shades. Molecular data shows at least five species in this group in California. Our most common form has a viscid, innately fibrillose, brown to olive-brown cap with violet to blue margin, violet to blue young gills, and violet to blue stipe with a bulbous base. It is common in live oak woodlands but also occurs with Douglas fir and tanbark oak in northern coastal forests and with spruce farther north.
Numerous poorly known, viscid-capped, marginate-bulbed Cortinarius species are known in California, differing in the color of the cap, young gills, stipe apex, and context. Those with violet cap, gills, and stipe have been referred to the Cortinarius sodagnitus group; those with yellow cap and gills and violet context to the Cortinarius cedretorum group; and those with olive-brown cap, green to olive gills, and bluish olive stipe to the Cortinarius scaurus group.
The flesh is mild tasting, and not highly regarded. It is considered a choice edible, and because it closely resembles many other species, including those that are deadly poisonous, it should definitely not be eaten. In Tlaxcala, Mexico, it is collected in June and sold in the market.
Other names: Bulbous Cortinarius, Blue-Foot Webcap, Schwachknolliger Klumpfuss (German), Cortinaire à pied glauque (French) and Szálaskalapú pókhálósgomba (Hungarian).
Cortinarius glaucopus Mushroom Identification
Mycorrhizal with conifers (especially) or hardwoods; growing scattered or gregariously; summer and fall, or overwinter in warmer climates; widely distributed in North America.
3-12 cm; convex, becoming broadly convex or nearly flat; sticky when fresh and young, but often dry when collected; bald over the center and silky toward the margin; developing radial streaks of innate fibers; variable in color, ranging from grayish olive to steely gray, yellowish-brown, rusty brown (or even bluish when young); the margin often notably paler (grayish to yellowish or olive), and often becoming wavy.
Attached to the stem, sometimes by a notch; close; lilac to pale purple at first, becoming rusty brown (often after a gray to the grayish stage).
4-10 cm long; to nearly 3 cm thick; more or less equal above a truncated, rimmed (at least when young), slightly bulbous base; usually lilac to pale purple when fresh and young, but often brownish to yellowish or dull olive with age; dry; often with rusty cortina remnants.
Whitish to yellowish, or purplish in the stem apex or near the gills.
Odor and Taste
KOH pinkish to reddish on the cap, brownish on flesh.
Spores 6-10 x 4-5.5 µ; ellipsoid to slightly amygdaliform; weakly verrucose. Pleuro- and cheilocystidia absent. Pileipellis an ixocutis (sometimes only slightly gelatinized) with clamped elements.
Similar species include C. caerulescens, C. pansa, C. sodagnitus, and C. subfoetens.
Cortinarius glaucopus Taxonomy
The species was first described as Agaricus glaucopus by Jacob Christian Schäffer in 1774. It was given its current name by Elias Magnus Fries in 1838. Within the genus Cortinarius, it is classified in the subgenus Phlegmacium and section Glaucopodes. A 2014 genetic study confirmed it was synonymous with C. glaucopoides and that Cortinarius subrubrovelatus was a distinct species.
Photo 1 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 2 - Author: Igor (Igor_Yevdokimov) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 3 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)
Photo 4 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)