A new anther smut fungus, Microbotryum crypticum is described based on specimens collected from the Japanese endemic plant, Silene miqueliana (Caryophyllaceae) in Osaka Prefecture, as well as from herbarium specimens of S. miqueliana preserved at the National Museum of Nature and Science (TNS) in Japan. Microbotryum crypticum is phylogenetically distinct from other anther smut fungi reported on Silene species and has relatively small spores compared to previously described Microbotryum species. Host preference further supports this new species. The presence of infected S. miqueliana plants in both herbarium and fresh specimens suggests that M. crypticum is widely distributed in Japan.

Amanita clarisquamosa and A. avellaneosquamosa, both of which belong to the section Amidella, were described in 1933 in Nopporo, Hokkaido, Japan. Owing to large intraspecific variation and high interspecific resemblance in morphology, species delimitation and identification of section Amidella members is difficult. This also applies to the two focal species. Furthermore, the minimality of the original descriptions of A. clarisquamosa and A. avellaneosquamosa exacerbates this problem. For reliable identification, detailed morphological and molecular information of reliably identified specimens, hopefully type specimens is required. However, further morphological and molecular information cannot be obtained from the degraded type specimens. In this study, new specimens that showed morphological and molecular matches with A. clarisquamosa and A. avellaneosquamosa were obtained from Nopporo and the surrounding areas of Hokkaido. Detailed morphology and barcoding region sequences of these specimens were recorded. Importantly, the newly collected specimens showed morphological and molecular mismatches with previously reported A. clarisquamosa or A. avellaneosquamosa specimens. This indicated that specimens previously identified as these two species might have included misidentifications. Overall, the study results suggest a need for reconfirmation of species within the section Amidella.

Mold contamination in library and museum collections poses risks to both cultural heritage and human health. This study examined fungal flora on books stored under controlled environmental conditions (temperature <20 °C, relative humidity <50%) in The University Museum, The University of Tokyo. Both culture-dependent methods and DNA-based metabarcoding targeting the internal transcribed spacer 2 region were used. DNA analysis revealed that Aspergillus halophilicus accounted for over 90% of the sequences from six books. In contrast, culture-based methods using standard media (e.g., PDA, DG18, M40Y) primarily isolated species such as Aspergillus, Penicillium, and Cladosporium, but not A. halophilicus. However, cultivation on CzA supplemented with 70% sucrose at lower temperatures enabled successful isolation of A. halophilicus from one sample. The strain was identified based on morphological features and β-tubulin gene analysis. These findings demonstrate a notable discrepancy between molecular and culture-based results, underscoring the limitations of conventional media for detecting xerophilic fungi in dry environments. The study suggests that desiccation-tolerant species like A. halophilicus can thrive even under strict storage controls and may evade standard integrated pest management (IPM) protocols. To better assess fungal risks in preservation settings, combining improved media with DNA-based methods is essential.