Cortinarius riederi (Weinm.) Fr., Epicrisis Systematis Mycologici: 259 (1838)
Collection date: 13 October 2018
Location: Skykomish area, King County, WA USA.
Habitat: Abies, Mountain hemlock, Western hemlock.
Description: Pileus: 48-72mm across. Cinnamon drab in center of cap to light cinnamon drab at cap margin. Margin with watery marks and dark fibrillose pattern, but no raised fibrils. Flesh: White to cream with thin layer of mottled lavender gray under surface of stipe and behind lamellae Lamellae: Lavender grey to endive blue Cortina: Lavender grey Stipe: 48-70mm tall and 12-14mm at stipe apex. Cream with slight overlay of lavender grey. Abrupt bulb, 22-26mm across. Chemical tests: KOH brown on cap and flesh
83% query cover, but 100% match to MH846265.1 which is A.H. Smith’s collection AHS17141 (MICH10397). This is the holotype of C. pseudoarquatus which was synonymized with C.riederi in Tor Erik Brandrud et al (2018) “Cortinarius sect. Riederi: taxonomy and phylogeny of the new section with European and North American Distribution”.