Considerations on the morphological features and phylogeny of the hypogeous gasteroid genera Sclerogaster and Wakefieldia (Basidiomycota) in North Macedonia

The genera Sclerogaster and Wakefieldia are infrequently reported, especially from poorly studied regions of the Balkan Peninsula. Research on hypogeous fungi in North Macedonia has been advancing steadily in recent years, leading to a growing number of collections in the Macedonian Collection of Fungi. Molecular phylogenetic and morphological observations of deposited specimens of Sclerogaster and Wakefieldia were performed, and compared with collections from other areas and sequences in nucleotide databases. Molecular genetic diversity based on rDNA ITS and LSU markers and morphological characteristics of the specimens from two genera are presented, and information on their ecology is provided. Two species of Sclerogaster: S. hysterangioides, reported for the first time for the Balkan Peninsula, and S. compactus, a second record for the Balkan Peninsula, were distinguished. Sclerogaster hysterangioides was found in different habitat types at four sites, while S. compactus was present at only one site in a riparian community of Populus alba and Ulmus laevis. The genus Wakefieldia is represented with a single species, W. macrospora, in Europe. Our collections, which constitute the second records for the Balkan Peninsula, originate from mixed deciduous forest of Quercus pubescens and Carpinus orientalis. The phylogenetic analyses confirm the morphological identification of the voucher specimens as S. hysterangioides and W. macrospora. The investigation of hypogeous fungi in North Macedonia demonstrates the rich diversity of this ecological group of fungi, and calls for future studies including comprehensive morphological observations and additional molecular markers.