Abstract
A saprobic member of Dothideomycetes was collected from dead branches of Fagus sylvatica in Italy. Morphology coupled with combined gene analysis of LSU, SSU, ITS and tefl-alpha sequence data, showed it to be a novel Montagnula species, which is introduced in this paper. Montagnula jonesii sp. nov. differs from other Montagnula species in having immersed, brown ascomata and ellipsoidal to fusiform, 3-septate ascospores with rounded ends and prominent guttules in each cell and is enlarged at the second cell from the apex. The new species is compared with other Montagnula species and a comprehensive description and micrographs are provided.