The taxonomic situation in the hyphomycete genera Penicillium, Aspergillus and Fusarium.

Classification of species in the three genera Penicillium, Aspergillus and Fusarium is in a state of change. Criteria used are reviewed; possible stabilization of nomenclature is envisaged. Proper typification of recognized species is necessary. In Penicillium and Aspergillus some species known mainly from fermented food are considered as domesticated versions of other, wild species. In Penicillium a further standardization of conditions of cultivation and careful description of micromorphology are necessary, before the species concepts of different laboratories can be reconciled. Secondary metabolites (mycotoxins, pigments) prove to support taxonomic conclusions reached by morphological work. In Aspergillus the taxonomic situation is simpler than in Penicillium, but typification is not yet sufficiently settled. For some well-known species older names were recently unearthed. In Fusarium the taxonomic views of different laboratories are becoming more similar, but much work on type specimens and neotypification of other species is still required. More genetic evidence is necessary to decide about specific or varietal rank in critical cases.