A new species of Coltricia, C. raigadensis is described from tropical region of Maharashtra, India. The species is recognized on the basis of morphological characteristics and phylogenetic analyses using rDNA ITS1-5.8S-ITS2, partial 28S rDNA and partial 18S rDNA sequences. Coltricia raigadensis is characterized by centrally stipitate basidiocarps, adpressed velutinate to tomentose pileal surface, small pores (2-4 per mm), globose to subglobose, thick walled basidiospores measuring 5.6-7 × 5-6.64 μm.

In 2017, two candidate species of Mycena were reported from Japan, with the Japanese names “Togari-sakura-take” and “Mitsuhida-sakura-take”. However, to date, no taxonomic study or formal description has been undertaken for these two species. In the present study, we conducted comprehensive morphological and molecular phylogenetic examinations of “Togari-sakura-take” and “Mitsuhida-sakura-take”, and compared them to known species within the genus Mycena. We performed phylogenetic analyses on a concatenated dataset, including the internal transcribed spacer region of ribosomal RNA, RNA polymerase II largest subunit, and translation elongation factor-1 alpha genes. “Togari-sakura-take” formed a clade with Mycena subulata, which was recently described from China, whereas “Mitsuhida-sakura-take” formed a distinct independent clade. We identified the former as M. subulata based on molecular phylogenetic analyses and morphological observations. However, the Japanese specimens displayed dextrinoid cheilocystidia and caulocystidia as well as the inamyloidity of basidiospores, which differed from the original description of M. subulata based on the materials from China. “Mitsuhida-sakura-take” was characterized by its remarkably dense lamellae and could be distinguished from known Mycena species by the combination of absent pleurocystidia and presence of bowling pin-shaped cheilocystidia. Here, we describe “Mitsuhida-sakura-take” as a new species, named Mycena densilamellata, in the section Calodontes.

Myxomycete distribution along urban-rural gradients remains to be studied in detail. The ancient plant Metasequoia glyptostroboides has been mainly planted in urban parks and green areas in Japan, and it provides new habitats for myxomycetes on its growing tree bark. Here, we examined myxomycetes on bark along urbanization gradients, estimated by land-use coverage types. Survey sites were selected at 20 locations in western Japan, where the bark was sampled from 10 trees at each site. The bark samples were cultured in 10 Petri dishes per tree using the moist chamber technique. Myxomycete fruiting colonies occurred in 71% of cultures, and 44 species were identified across surveys. Diderma chondrioderma occurred at all sites, with the next most abundant species being Licea variabilis and Perichaena vermicularis. Twenty-two myxomycete communities ordinated using non-metric multidimensional scaling showed a significant negative correlation with building coverage and bark pH, increasing along the first axis. Relative abundances of Physarum crateriforme and Licea biforis positively correlated with increasing building coverage. Overall, urbanization causes alternation of the myxomycete community structure without diversity loss, and intermediate urbanization diversified species diversity on M. glyptostroboides tree bark.

Pythium amaminum sp. nov. was isolated from river and reservoir water on Amami island, Kagoshima Prefecture, Japan. The species can grow at temperatures between 10 °C and 35 °C. At the optimum temperature of 25 °C, the radial growth rate is 22.5 mm per day. Pythium amaminum produces filamentous sporangia consisting of branched, lobulate or digitate elements forming large complexes. Zoospores form inside the vesicle, which is discharged through a long tube at least 320 μm. Globose oogonia are ornamented with conical blunt spines. Oospores are aplerotic and globose. Antheridia twine around the oogonia or stick to them. These features having a both of the long discharge tube from sporangium and oogonia with spines are not observed in any other species of the genus Pythium, and thus we conclude that P. amaminum is a new Pythium species.

The reproduction and dispersal strategies of lichens play a major role in shaping their population structure and photobiont diversity. Sexual reproduction, which is common, leads to high lichen genetic diversity and low photobiont selectivity. However, the lichen genus Endocarpon adopts a special co-dispersal model in which algal cells from the photobiont and ascospores from the mycobiont are released together into the environment. To explore the dispersal strategy impact on population structures, a total of 62 Endocarpon individuals and 12 related Verrucariaceae genera individuals, representing co-dispersal strategy and conventional independent dispersal mode were studied. Phylogenetic analysis revealed that Endocarpon, with a large-scale geographical distribution, showed an extremely high specificity of symbiotic associations with their photobiont. Furthermore, three types of group I intron at 1769 site have been found in most Endocarpon mycobionts, which showed a high variety of group I intron in the same insertion site even in the same species collected from one location. This study suggested that the ascospore-alga co-dispersal mode of Endocarpon resulted in this unusual mycobiont-photobiont relationship; also provided an evidence for the horizontal transfer of group I intron that may suggest the origin of the complexity and diversity of lichen symbiotic associations.

The present study introduces a novel fungus, Cystoderma yongpingense, which was identified in the southwestern region of China. The new species is characterized by a pileus that ranges in color from light orange-red to orange-red; the pileus has a wrinkled surface and is accompanied by a persistent annulus that is membranous and floccose-scaly. Above the annulus, the color transitions from white to yellowish brown. This proposal is substantiated through analyses encompassing both morphological characteristics and phylogenetic relationships. The phylogenetic position of the newly discovered species has been further corroborated through comprehensive maximum likelihood and Bayesian sequence analyses of the ITS + nrLSU DNA regions. Additionally, the technical description of C. yongpingense is enhanced by detailed illustrations and comparative studies with species that are closely related.