Phlegmacium boreicyanites is a species of fungus in the family Cortinariaceae[1]
It was originally described in 2014 and classified as Cortinarius boreicyanites. It was placed in the (subgenus Phlegmacium) of the large mushroom genus Cortinarius.
In 2022 the species was transferred from Cortinarius and reclassified as Thaxterogaster argyrionus based on genomic data.[2]
Its fruitbodies have hemispherical to convex caps measuring 4– in diameter. Initially bluish gray, the cap colour matures to pale grayish brown. Gills on the cap underside have an emarginate attachment to the stipe. They start out greyish blue before changing to brownish violet when the spores mature. The club-shaped to bulbous stipe measures 5– long, and up to 4cm (02inches) wide at the base.
The specific epithet boreicyanites refers to its close relationship to Cortinarius cyanites, and its boreal distribution.
Found in the boreal mixed forests of Europe (Sweden, Finland and Scotland).