Cortinarius glutinosoarmillatus Bojantchev, Ammirati, Liimat. & Niskanen 2017

mycobank MB 823833

Type: USA. California: Contra Costa County, Mt. Diablo State park, (37°52′31″N 121°55′42″W), elev. 800 ft, under Quercus agrifolia 21 Jan 2008, DBB06703(Holotype WTU-F-069225; Genbank nrITS MG708298);

Additional Collections examined: USA. California: Marin County, Lake Lagunitas (37°56′42″N 122°35′34″W), elev. 800ft, under Q. agrifolia, 16 Dec 2016, DBB80001 (Genbank nrITS MG720068);  San Mateo County, El Corte De Madera Creek Open Space (37°23′56″N 122°17′45″W), elev. 810, under Quercus agrifolia 1 Apr 2012, DBB50201 (Genbank nrITS MG720069); Mendocino County, Mendocino Woodlands State Park (37°56′42″N 122°35′34″W), elev. 600ft, under Notholithocarpus densiflorus, Pseudotsuga menziesii and Sequoia sempervirens 21 Nov 2009, DBB27745 (Genbank nrITS MG720067);

Etymology: From Latin: “glutinoso” = glutinous and “armilla” = bracelet.

Fig 1 Cortinarius glutinosoarmillatus DBB06703.

Pileus 40–100 mm diam., convex to plano-convex to broadly umbonate, margin involute, wavy in  age, color olive blue to olive yellow at first, darker ocherish on the disk, remaining olive blue on the margin, profusely gelatinous when moist, velar remnants often sticking on the margin. Lamellae sinuate, moderately crowded, 6–12 mm broad, light bluish or whitish at first then pale yellow to pale bluish, darker yellow, turning rusty brown as spores mature; edges even; lamellulae abundant. Stipe 80–160 mm long, 18–30 mm wide, cylindrical to subclavate, with distinct gelatinous girdles forming as the stipe lengthens ,the gelatinous layer separating  more on  the lower half, distinct annular zone present near the apex, ground color pale white to bluish overall, bluish at the apex, then discoloring to yellow brown where the gelatinous surface layeris lost. Universal Veil white, gelatinous. Cortina whitish, gelatinous. Context on pileus and stipe, whitish at the center, often bluish at the edge. Odor not distinct. UV negative. Macrochemical Reactions 5% KOH no reaction. Spore Deposit dark rusty brown.

Basidiospores (13.2–) 14.0–15.0 (–15.5) × (7.5–) 7.8–8.3(–8.7) µm (mean 14.3 × 8.0 µm) (N = 33, 2 basidiomata, one collection), ellipsoid to amygdaloid, strongly verrucose. Basidia 28–42 × 7–11 µm, 4-spored, cylindrico-clavate. Lamella edge sparsely fertile. Cystidia not observed. Lamellar Trama regular, composed of more or less parallel, cylindrical hyphae, 4–7 µm wide. Pileipellis composed of thin entangled hyphae (3-7 µm) suspended in a thick gelatinous layer, hyaline to yellow intercellular pigment. Clamp connections common on all septa.

Discussion — Cortinarius glutinosoarmillatus is one of the most common species under live oaks in California and occasionally occurs under tanoak. It is reported from the broader Pacific Northwest under cottonwoods and aspen, but we have not been able to obtain specimens for study. The fruiting period is from late fall to early spring. Cortinarius glutinosoarmillatus was known as C. trivialis sensu auct. CA for a long time, but differs morphologically significantly from its European relatives by the range of coloration and the somewhat larger spores. The tanoak collections of this species tend to have paler and more yellowish coloration with fewer bluish tinges than the oak collections. Genetically, C. glutinosoarmillatus has a large gap of 59 missing base pairs in its ITS1 region, compared to its closest relatives.

Fig 2 Cortinarius glutinosoarmillatus DBB50201

Fig 3 Cortinarius glutinosoarmillatus DBB50201

Fig 4 Cortinarius glutinosoarmillatus DBB27745 – collection under tanoak.

Fig 5 Cortinarius glutinosoarmillatus DBB27745 spores (~14.3 × 8.0 µm)

Fig 6 Cortinarius glutinosoarmillatus has 59 missing bp in the ITS1 sector.