Taxonomic re-evaluation of species in Talaromyces section Islandici, using a polyphasic approach

The taxonomy of Talaromyces rugulosus, T. wortmannii and closely related species, classified in Talaromyces sect. Islandici, is reviewed in this paper. The species of Talaromyces sect. Islandici have restricted growth on MEA and CYA, generally have yellow mycelia and produce rugulosin and/or skyrin. They are important in biotechnology (e.g. T. rugulosus, T. wortmannii) and in medicine (e.g. T. piceus, T. radicus). The taxonomy of sect. Islandici was resolved using a combination of morphological, extrolite and phylogenetic data, using the Genealogical Concordance Phylogenetic Species Recognition (GCPSR) concept, with special focus on the T. rugulosus and T. wortmannii species complexes. In this paper, we synonymise T. variabilis, Penicillium concavorugulosum and T. sublevisporus with T. wortmannii, and introduce four new species as T. acaricola, T. crassus, T. infraolivaceus and T. subaurantiacus. Finally, we provide a synoptic table for the identification of the 19 species classified in the section.