We studied the diversity of arbuscular mycorrhizal fungi (AMF) in semiarid sandy areas of the Great Hungarian Plain representing the westernmost of the Eurasian steppe belt. AM fungal spores were extracted (i) directly from soils collected around 30 Juniperus communis trees of three sampling sites and (ii) from pot trap cultures established with soils from those samples. Altogether spores of 31 AMF species belonging to 15 genera were identified from the field and pot-culture samples. Three taxa could be identified only on the genus level. During the study, one fungus showed a unique combination of morphological characters. Molecular phylogenetic analyses of SSU, ITS, and LSU regions of the nrDNA positioned the fungus in the genus Diversipora and confirmed its novelty when compared with all Diversipora spp. species sequenced to date. This fungus is here described as D. jakucsiae sp. nov.