Taxonomic reintroduction of (Taphrinales, Ascomycota) associated with as one of five well defined European species colonizing alders.

Phylogenetic analysis of four DNA regions (ITS, LSU, mtSSU and ) supported the existence of five European species which colonise in Europe. In addition to previously well-defined species, is, for the first time recognised, by molecular study as a species related to . Analysis of publicly available sequences of barcoding regions suggested that is only associated with and no other species colonize this host tree. Symptomatic, morphological, and physiological characterisation of are provided together with the key for identification of associated species in Europe and North America.