A new heat-resistant species of Leiothecium (Eurotiales, Ascomycota) from Argentina. A new heat-resistant species of Leiothecium (Eurotiales, Ascomycota) from Argentina

Leiothecium is a genus accommodated in the family Aspergillaceae (Eurotiales) including L. ellipsoideum and L. cristatum, species exhibiting ascospore walls somewhat or irregularly reticulated and prominent crests. During a research on heat-resistant fungi from the semi-arid region of Northern Argentina, several Leiothecium spp. isolates were obtained and studied from morphological and phylogenetic points of view. Phylogenetics showed strong support for the monophyly of the Leiothecium sp nov. clade and L. ellipsoideum as the sister taxa. L. ellipsoideum was determined, and a new species provided with reticulate-foveate ascospore ornamentation without prominent crests was described: L. dictyophorum S. M. Romero, Stchigel & Comerio sp. nov. Molecular and scanning electron microscopy (SEM) analysis displayed a critical role in revealing L. dictyophorum. For comparison and determination purposes, optical and SEM photography illustrations of Argentinean isolates of L. ellipsoideum and L. dictyophorum were presented.