Cortinarius duboisensis – Facesoffungi number: FoF 02040

Cortinarius duboisensis Ammirati, Beug, Niskanen & Liimat

Index Fungorum number: IF 551704 Facesoffungi number: FoF 02040

Etymology: Named for DuBois Lake, the original name of Roland Lake in Washington, USA

Holotype: Joseph Ammirati JFA13311(WTU) Pileus 50–135 mm diam., broadly obtuse-umbonate to plano-umbonate then±plane to uplifted, margin decurved at first, mature becoming irregular and lacerated, easily broken, surface moist to dry, not striate, center often with whitish bloom, margin in places silky or with thin coating of whitish fibrils, colour variable, when moist watery dark brown to watery grey brown, faded areas ochraceous tawny, light brown, brownish buff or light buff, center sometimes very pale, margin frequently finely rivulose-variegated or streaked with brown colours, sometimes with darker areas or blotches, hygrophanous. Lamellae adnexed, close to subdistant, very broad, moderately thick to thick, somewhat easily broken, pale brown at first or in non-spore covered areas, rich deep brown when mature, edges irregular. Stipe 45–135 mm long, 10–32 mm thick above, base 23–35 mm thick, varies from narrow clavate to bulbous, upper surface shiny, sometimes twisted striate, whitish to pallid-white, with some thin darker watery buff brown streaks, without veil remains above. Universal veil white. Basal mycelium white and extends up onto base of the stipe. Context whitish to pallid or brownish white, darkening with age and with exposure, watery brown streaked in stipe, cortex rather tough, lower stipe flesh soon grayish then much darker brown, especially in stipe base. Odour strong fungoid to mildy woodsy. Taste mild, fungoid. Macrochemical reaction (40 % KOH): on pileus surface raw umber, pileus context bronze, stipe apex, pinkish buff exterior, interior of stipe including stipe base, fuscous black. Exsiccatae: pileus grey brown to rather dark grey brown, lamellae dark brown, stipe whitish to pallid or greyish with a few blackish areas, context similar to stipe surface, basal mycelium white. Basidia 4-spored, 8.5–9×29–48μm, clavate, hyaline or pale brownish in KOH. Basidiospores 8.9– 10.2×5–6.2μm (20 spores, holotype specimens), ellipsoid, broadly ellipsoid or somewhat amygdaloid, moderately verrucose, somewhat to strongly dextrinoid. Lamella trama hyphae smooth, not encrusted in KOH. Pileipellis in KOH: Surface hyphae±cylindrical, 4–14μm wide, hyaline or brownish, some encrusted. Subtending layer of cylindrical to enlarged hyphae 4–20μm wide, hyaline, not encrusted. Beneath a brown pigmented layer of cylindrical to enlarged hyphae 8– 22μm wide, grading into trama hyphae. ITS sequence distinct from the other known members of the subgenus Telamonia, and differs from them in the ITS region by more than 15 substitutions and indel positions.

Ecology and distribution: Collections have been made under Quercus garryana, Pinus ponderosa or a mixture of Quercus garryana, Pinus ponderosa and Abies grandis. Producing basidiomata in late autumn. Known from Washington, Western North America.

Material examined: USA, Washington, Klickitat County, Roland Lake, 47.36 N 122.73 W, ecology, Quercus garryana and Pinus ponderosa, 28 Nov 2008, leg. Joseph F. Ammirati JFA13308 (WTU, K), JFA13311 (holotype, WTU), (isotype, K), JFA13312 (WTU). Klickitat County, Lower Staats Road, N45°50′38.5″, W121°24 ′ 44.1″, Quercus garryana, Pinus ponderosa and Abies grandis, 18 Nov 2013, leg. Michael Beug 01MWB111813 (WTU, K).

Notes: Cortinarius duboisensis is a rather large species with dark brown to watery grey brown pileus with a whitish bloom in the center and clavate to bulbous stipe. Typical are also exsiccatae with grey brown to rather dark grey brown pileus and whitish to greyish stipe. Cortinarius duboisensis is related to C. crassisporus Kytöv., Niskanen & Liimat. which also has basidiomata with bulbous stipe and brown pileus. Cortinarius crassisporus, however, has larger spores(10.7–13.6×7.5–9.1μm) and occurs in hemiboreal– boreal and mountain coniferous forests on calcareous soil.The species are morphologically most reminiscent to those of section Bovini, but do not seem to belong to that section based on our phylogenetic analysis.