Phlegmacium boreidionysae is a species of fungus in the family Cortinariaceae.[1]
It was originally described in 2014 by the mycologists Ilkka Kytövuori, Kare Liimatainen, Tuula Niskanen, and Balint Dima who classified it as Cortinarius boreidionysae. It was placed in the (subgenus Phlegmacium) of the large mushroom genus Cortinarius.
In 2022 the species was transferred from Cortinarius and reclassified as Phlegmacium boreidionysae based on genomic data.[2]
The specific epithet boreidionysae refers to its close relationship to C. dionysae, and its boreal distribution.
Found in Finland, it grows in northern boreal forests of predominantly Norway spruce (Picea abies).