Wood-inhabiting fungi are noteworthy components of woody ecosystems that are responsible for the decomposition and turnover of wood nutrients. While the diversity and ecology of these fungi in the temperate forests has been relatively well explored, little is known on diversity of these fungi in the arid and semi-arid forest ecosystems. This is the first study on diversity, distribution, and ecology of the fungal genus Hyphodontia s.l. in the five countries of Central Asia, viz., Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. Altogether, 11 species are confirmed for the region, among which the following six species are reported for the first time from Central Asia: Hyphodontia alutaria, H. pallidula, Kneiffiella alutacea, Lyomyces crustosus, L. erastii, and L. sambuci. In addition to the morphological evidence, the identity of three species is confirmed with phylogenetic analysis based on ITS nuclear ribosomal DNA region. The spectra of known hosts for many of the studied species were expanded. An annotated species list and geo-referenced distribution maps are provided as well as notes on taxonomy, ecology, and local, regional, and global distribution. An identification key to the species of Hyphodontia s.l. recorded in arid and semi-arid regions of Central Asia is also provided.

Diversity of corticioid fungi (resupinate Basidiomycota), especially outside the northern temperate climatic zone, remains poorly explored. Furthermore, most of the known species are delimited by morphological concepts only and, not rarely, these concepts are too broad and need to be tested by molecular tools. For many decades, the delimitation of species in the genus Subulicystidium (Hydnodontaceae, Trechisporales) was a challenge for mycologists. The presence of numerous transitional forms as to basidiospore size and shape hindered species delimitation and almost no data on molecular diversity have been available. In this study, an extensive set of 144 Subulicystidium specimens from Paleo- and Neotropics was examined. Forty-nine sequences of ITS nuclear ribosomal DNA region and 51 sequences of 28S nuclear ribosomal DNA region from fruit bodies of Subulicystidium were obtained and analysed within the barcoding gap framework and with phylogenetic Bayesian and Maximum likelihood approaches. Eleven new species of Subulicystidium are described based on morphology and molecular analyses: Subulicystidiumboidinii, S.fusisporum, S.grandisporum, S.harpagum, S.inornatum, S.oberwinkleri, S.parvisporum, S.rarocrystallinum, S.robustius, S.ryvardenii and S.tedersooi. Morphological and DNA-evidenced borders were revised for the five previously known species: S.naviculatum, S.nikau, S.obtusisporum, S.brachysporum and S.meridense. Species-level variation in basidiospore size and shape was estimated based on systematic measurements of 2840 spores from 67 sequenced specimens. An updated identification key to all known species of Subulicystidium is provided.

Morphology of organisms is an essential source of evidence for taxonomic decisions and understanding of ecology and evolutionary history. The geometric structure (i.e., numeric description of shape) provides richer and mathematically different information about an organism’s morphology than linear measurements. A little is known on how these two sources of morphological information (shape vs. size) contribute to the identification of organisms when implied simultaneously. This study hypothesized that combining geometric information on the outline with linear measurements results in better species identification than either evidence alone can provide. As a test system for our research, we used the microscopic spores of fungi from the genusSubulicystidium(Agaricomycetes, Basidiomycota). We analyzed 2D spore shape data via elliptic Fourier and principal component analyses. Using flexible discriminant analysis, we achieved the highest species identification success rate for a combination of shape and size descriptors (64.7%). The shape descriptors alone predicted species slightly better than size descriptors (61.5% vs. 59.1%). We conclude that adding geometric information on the outline to linear measurements improves the identification of the organisms. Despite the high relevance of spore traits for the taxonomy of fungi, they were previously rarely analyzed with the tools of geometric morphometrics. Therefore, we supplement our study with an open access protocol for digitizing and summarizing fungal spores’ shape and size information. We propagate a broader use of geometric morphometric analysis for microscopic propagules of fungi and other organisms.