Cortinarius

Cortinarius is a globally distributed genus of fungus in the family Cortinariaceae.^[1] Its members are commonly known by the names cortinar and webcap. It is suspected to be the largest genus of agarics, containing over 2,000 widespread species.

Cortinarius
Cortinarius archeri
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Cortinariaceae
Genus:	Cortinarius (Pers.) Gray (1821)
Type species
Cortinarius violaceus (L.) Gray (1821)
Diversity
ca. 2000 species

C. violaceus

Young specimens have a cortina (veil) between the cap and the stem, hence the name. Most of the fibres of the cortina are ephemeral and leave no more than limited remnants on the stem or cap edge. All species have a rusty brown spore print. Several species (such as C. orellanus) are highly toxic and many species are difficult to distinguish, making their consumption inadvisable.

Taxonomy

Molecular studies of members of the genus Rozites, including its most famous member R. caperata, have shown them nested within Cortinarius and have been sunk into this genus. This genus was erected on the basis of a double veil, yet its members do not form a discrete lineage and lie nested within Cortinarius. Hence the genus is no longer recognised.^[2]

Some consider the subgenus Dermocybe to have generic status.^[3] Although it forms a single lineage, the consensus has been to sink it into the larger genus.^[4]

It is suspected to be the largest genus of agarics, containing over 2,000 widespread species.^[5]

In reference to the veil, the genus name means 'curtained'.

Selected species

Main article: List of Cortinarius species

• Cortinarius austrovenetus - also known as Dermocybe austroveneta or green skin-head is an Australian fungus typical of the brightly coloured Dermocybe subgenus.
• Cortinarius caperatus, the "gypsy mushroom", is an edible mushroom found in northern regions of Europe and North America.
• Cortinarius orellanus and C. rubellus are two of the deadly webcaps found in Europe and North America.

Description

The veil protects the gills in younger specimens and usually disappears leaving little to no trace of itself as the mushroom grows. The spores are rusty brown to brownish-red in color.

It is usually possible to identify a mushroom as being a member of the genus, but extremely difficult to positively identify the species as many of the species are nearly identical. All mushrooms in this genus form mycorrhizae.^[6]

Toxicity

Several Cortinarius species are poisonous, mainly because they cause acute tubulointerstitial nephritis. Some are even lethal, such as C. rubellus and C. orellanus. Many Cortinarius varieties can be mistaken for other edible mushrooms (such as the blewit) and should therefore be researched before consumption.

The toxin in Cortinarius species, orellanine, is easy to detect because it is fluorescent. It has been found in at least 34 Cortinariaceae.^[7]

Uses

Some species—notably the species C. praestans and C. caperatus—are edible and appreciated in several European cuisines.^{[citation needed]}

Many mushrooms in the genus, for example C. sanguineus and other species in section Dermocybe, are colourful and are often used for dyeing.^{[citation needed]}