RESUMEN
We describe two novel fungi isolated from soil samples collected in Northern Argentina and belonging to the family Aspergillaceae of the order Eurotiales: Leiothecium cristatum sp. nov. and Aspergillus posadasensis sp. nov. Leiothecium cristatum sp. nov., represented by the ex-type strain FMR 11998(T) (â=âCBS 134260(T)â=âNBRC 109843(T)), is distinguishable morphologically from the type species of the genus, Leiothecium ellipsoideum, by the presence of irregular reticulate ascospores with two prominent equatorial crests, and Aspergillus posadasensis sp. nov., represented by the ex-type strain FMR 12168(T) (â=âCBS 134259(T)â=âNBRC 109845(T)), is differentiated from Aspergillus acanthosporus, the nearest species phylogenetically, by its non-sclerotioid ascomata and a lack of an asexual stage on all culture media tested. The taxonomic proposals are supported by the analysis of the sequences of the internal transcribed spacer region, the D1-D2 domains of the 28S rRNA gene, the fragments of the RNA polymerase II largest subunit, and the putative chaperonin complex related to TCP-1, ß-tubulin and calmodulin genes.