Taxonomic identity of Melampsora ferrinii on Salix with M. coleosporioides

Three willow rust fungi, Melampsora babylonicae, M. coleosporioides and M. ferrinii, are morphologically similar and share comparable host associations. Morphological and phylogenetic analyses revealed that M. coleosporioides and M. ferrinii are taxonomically indistinguishable, while M. babylonicae is phylogenetically distinct and is therefore provisionally treated as a separate species. As a result, M. ferrinii is synonymized with M. coleosporioides and the description of M. coleosporioides is accordingly emended. The life cycle, host plant range, and geographic distribution of this rust fungus are described and discussed based on existing literature.