Cortinarius collinitus group

Cortinarius collinitus (Sowerby) Gray, A natural arrangement of British plants 1: 628 (1821) [MB#225177]

Description
Cap 30 – 75 mm, convex with obtuse umbo, viscid, slimy, ochre to dark red-brown when moist, paler at margin, drying to brassy yellow-brown to yellow-ochre at margin, sometimes with darker brown blotches, Gills greyish, cream, to pale brown, later cinnamon brown, stipe 35 – 80 mm long, 8 – 20 mm wide at apex, firm, cylindrical, very viscid, commonly with blue-violet or grey-blue colors on stipe, browning from base, glutin forming a sheath joining stipe to cap, flesh whitish near apex, slight lilac under upper surface, yellowish to brown towards base spores, large (published records say 13 – 16 x 7.5 – 9.5 microns, my records show some spores even larger than this.)

Discussion:

The concept of Cortinarius collinitus has a troubled history and we still lack access to a barcode of a neotype. However, we know enough to recognize and name a relatively common PNW species to ‘group’, while understanding that at least one similar undescribed species likely occurs here too.

There are several similar species in Section Myxacium: Cortinarius septentrionalis, mucosus and trivialis among them. Cortinarius pinguis is in the same section (note the lilac glutin sometimes observed on fresh collections) but is a secotiod species not likely to be confused.

• Cortinarius collinitis – glutin on stipe lilac when fresh, seldom supposedly rarely white but often in NAm collections, browning from stipe base, largest spores of these species. Coniferous forest (in EU grows with spruce). Spores large.
• Cortinarius mucosus – typically has a white / cream stype without lilac tones, cap tends to be a bit darker brown, narrow spores, Conifer forest (grows with pine).
• Cortinarius septentrionalis – may have lilac stipe, cap color is a brighter orange with dark disc. I have only seen this in AK (with birch).
• Cortinarius trivialis – distinctive cracking of glutin on stipe, leading to girdles and scales on the stipe, blue-grey young gills. Deciduous forest. Occurs in PNW with cottonwood / poplar.

TL:DR:
The trouble with Cortinarius collinitis occured due to a lack of consensus over the legitimate name for a relatively common and well known species. The original description by Sowerby appears to have illustrated a different species (see Bendriksen et al 1992 and 1993 for summary). Gray transferred the name from Agaricus to genus Cortinarius, but his description was scant and referenced scales (girdles) typical of Cortinarius trivialis.

Fries included the species in his Systema Mycologicum (1821), also references features that made the concept ambiguous (broken scales on stipe, violet gills, similarity to A. caperatus)

As mycologists debated the concept of the original description – new species sub-species, and varietals were published ultimately complicating the situation, since several of these appear to be synonyms (see Smith 1944, Bendikson 1993). Some ‘forensic’ taxonomy has been done to try and resolve the problem but a neotype has not yet been published, and synonyms are not yet accepted in all circles.

Author	Name	Date	Note
Sowerby	Agaricus collinitus	1797	Lilac stipe. Some banded
Gray	Cortinarius collinitus	1821
Fries	Protologue	1821
Peck	Cortinarius muscigenus = Synonym?	1888
Smith	Cortinarius collinitus var. typicus f. caerulipes = Synonym?	1944
Smith	Cortinarius mucosus var. caerulipes = Synonym?	1944
Henry	Cortinarius coeruleolutescens = Synonym?	1984

Recent phylogentic work documents at least two species that leading Cortinarius experts refer to as collinitus. Soop et al (2019) call them Cortinarius collinutus and Cortinarius collinitus II.

ITS

All pictured collections have identical ITS. They map to C. collinitus UC-F17113 on Soop’s tree and AY669588 on Genbank, which is the same species Garnica et al (2005) designated as C. collinitus in their phylogentic classification of the genus. Note the second species ‘C. collinitus II‘ also in the section.

>NS4589
GGAAGTAAAAGTCGTAACAAGGTTTCCGTAGGTGAACCTGCGGAAGGATCATTATTGAAATAAACCTGATGAGTTGTTGCTGGTTCTCTAGAGAGCATTGTGCACGCTTGTCATCTTTATGTCTCCACCTGTGCACATTTTGTAGACCTGGATCACTCTCTGAAATGCTAACCAGCATTTTAGGTTGGAGGAATTTGACTTTGTTGTCTTTCCTTGCATTTCTAGGTCTATGTTTTTTCATATAATCTTATTGTGATATAATGGGCCCTATATAATATAAACTTATACAACTTTCAGCAACGGATCTCTTGGCTCTCGCATCGATGAAGAACGCAGCGAAATGCGATAAGTAATGTGAATTGCAGAATTCAGTGAATCATCGAATCTTTGAACGCACCTTGCGCTCCTTGGTATTCCGAGGAGCATGCCTGTTTGAGTGTCATTAATATATCAACCTCTTTAAATTTTGAGAGTGTTTGGATGTGGGGGTGTTATTTTGCTGGCCTTCTCCAAGGTCAGCTCCCCTGAAATGTATTAGCGGAACAATTTGTTGACCGTTCATTGGTGTGATAGCATATCTACGCTATTGACGTAAAGCAAGTTCAGCTTATAACAGTCCATTGACTTGGACAATTCTCTATTTATTAATGTGACCTCAAATCAGGTAGGACTACCCGCTGAACTTAAGCATATCAATAAGCGGAGGAAAAGAAACTAACAAGGATTCCCCTAGTAACTGCGAGTGAAGCGGGAAAAGCTCAAATTTAAAATCTGTCAGTCTTTGGCTGTCCGAGTTGTAATCTAGAGAAGTGTTATCCGCGC

References:
Egil Bendiksen, K Bendiksen, and Tor Erik Brandrud, “What Is Cortinarius Cylindripes Kauffman,” Persoonia 14, no. 4 (1992): 583–85.

E. Bendiksen, K. Bendiksen and & T.E. Brandrud, “Sommerfeltia-019-1993 Cortinarius Subgenus Myxacium Section Colliniti.Pdf,” Sommerfeltia, 1993.

Sigisfredo Garnica et al., “A Framework for a Phylogenetic Classification in the Genus Cortinarius (Basidiomycota, Agaricales) Derived from Morphological and Molecular Data,” Canadian Journal of Botany 83, no. 11 (November 2005): 1457–77, https://doi.org/10.1139/b05-107.

Peinter et al., “Multiple Origins of Sequestrate Fungi Related to Cortinarius (Cortinariaceae),” American Journal of Botany 88, no. 12 (2001): 2168–79.

Michelle Seidl, “Phylogenetic Relationships within Cortinarius Subgenus Myxacium, Sections Defibulati and Myxacium,” Mycologia, Mycological Society of America. 92, no. 6 (December 2000): 1091–1102.

Alexander H. Smith, “New and Interesting Cortinarii from North America,” Lloydia 7 (September 1944): 163–235.

Soop et al., “A Phylogenetic Approach to a Global Supraspecific Taxonomy of Cortinarius ( Agaricales ) with an Emphasis on the Southern Mycota,” Persoonia – Molecular Phylogeny and Evolution of Fungi 42, no. 1 (July 19, 2019): 261–90, https://doi.org/10.3767/persoonia.2019.42.10.