show Abstracthide AbstractA considerable portion of fungal infections are caused by cryptic species, which are morphologically indistinguishable from already described pathogenic species but differ genetically and (often) in infection-relevant traits. The origin, genetic diversity, and variation in infection-relevant traits of the cryptic fungal pathogen Aspergillus latus - an allodiploid hybrid of two other known fungal species in section Nidulantes, Aspergillus spinulosporus and an unknown close relative of Aspergillus quadrilineatus - remains poorly understood. To address these questions, we studied the genomes, transcriptomes, chemotypes and phenotypes of 44 globally distributed isolates (41 clinical isolates; three type strains) from Aspergillus section Nidulantes; we found that 21 clinical isolates were A. latus, whereas the others were A. spinulosporus (8), A. quadrilineatus (1), or A. nidulans (11).