Contribution to the Discussion on the Species Concept in the Pleurotus ostreatus Complex

Abstract
Macroscopic and microscopic characteristics are unreliable for classification within the P. ostreatus species complex. So are also negative interstrain matings. Considering strain intercompatibilities reported by different authors, European P. ostreatus, P. pulmonarius, P. columbinus and American P. sapidus belong to the same species. American strains that were intersterile with all other strains deserve further attention.