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Among many convergently evolved sequestrate fungal genera in Boletaceae (Boletales, Basidiomycota), the genus Octaviania is the most diverse. We recently collected many specimens of Octaviania subg. Octaviania, including several undescribed taxa, from Japan and the Americas. Here we describe two new species in subgenus Octaviania, O. tenuipes and O. tomentosa, from temperate to subtropical evergreen Fagaceae forests in Japan based on morphological observation and robust multilocus phylogenetic analyses (nrDNA ITS and partial large subunit [LSU], translation elongation factor 1-α gene [TEF1] and the largest subunit of RNA polymerase II gene [RPB1]). Based on specimens from the Americas as well as studies of the holotype, we also taxonomically re-evaluate O. asterosperma var. potteri. Our analysis suggests that O. asterosperma var. potteri is a distinct taxon within the subgenus Octaviania so we recognize this as O. potteri stat. nov. We unexpectedly collected O. potteri specimens from geographically widespread sites in the USA, Japan and Colombia. This is the first verified report of Octaviania from the South American continent. Our molecular analyses also revealed that the RPB1 sequence of one O. tenuipes specimen was identical to that of a closely related species, O. japonimontana, and that one O. potteri specimen from Minnesota had an RPB1 sequence of an unknown species of O. subg. Octaviania. Additionally, one O. japonimontana specimen had an unusually divergent TEF1 sequence. Gene-tree comparison and phylogenetic network analysis of the multilocus dataset suggest that these heterogenous sequences are most likely the result of previous inter- and intra-specific hybridization. We hypothesize that frequent hybridization events in Octaviania may have promoted the high genetic and species diversity found within the genus. [ABSTRACT FROM AUTHOR]

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We describe and illustrate two new species of Boletellus section Boletellus, B. aurocontextus sp. nov. and B. areolatus sp. nov., which are generally assumed to be B. emodensis. In this study, we reconstructed separate molecular phylogenetic trees of section Boletellus using the nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, the largest subunit (RPB1) and the second-largest subunit (RPB2) of nuclear RNA polymerase II gene and mitochondrial cytochrome oxidase subunit 3 (cox3) gene. We also examined the morphologies of B. emodensis sensu lato (s.l.) and other related species for comparison. The molecular phylogenetic tree inferred from the sequences of nuclear DNA (ITS, and combined dataset of RPB1 and RPB2) indicated that three genetically and phylogenetically well-separated lineages were present within B. emodensis s.l. These three lineages were also distinguished on the basis of the molecular phylogenetic tree constructed using the sequences of mitochondrial DNA (cox3), suggesting distinct cytonuclear disequilibria (i.e., evidence of reproductive isolation) among these lineages. Therefore, these three lineages can be treated as independent species: B. aurocontextus, B. areolatus, and B. emodensis. Boletellus aurocontextus and B. areolatus are also distinct from B. emodensis by the macro- and microscopic morphologies. Boletellus aurocontextus is characterized by a pileus with bright yellow to lemon yellow context, which can be observed through a gap in the scales, and basidiospores with relatively large length (mean spore length, 21.4 μm; quotient of spore length and width, 2.51). In contrast, B. areolatus is characterized by a pileus with floccose to appressed thin scaly patches, a stipe with pallid or pale cream color at the upper half, and basidiospores with relatively small length (mean spore length, 16.5 μm; quotient of spore length and width, 1.80). [ABSTRACT FROM AUTHOR]

We describe and illustrate two Strobilomyces species, S. seminudus and S. hongoi sp. nov. These two species have been confused and treated as a single species (i.e. S. seminudus). However recent studies based on population genetics have implied that they are reproductively isolated. In the present study we found that they are phylogenetically and morphologically distinct. The molecular phylogenetic trees inferred from the partial sequences of the largest subunit of RNA polymerase II (RPB1) and the second-largest subunit of RNA polymerase II (RPB2) support the differentiation of these two species as well as their differentiation from other related species. Strobilomyces seminudus is characterized by a stipe with an annular zone, becoming distinctly thickened near the apex and mottled with appressed-tomentose scales near the base. In contrast S. hongoi is characterized by a stipe with a remarkable reticulum at the upper and middle part and with minutely warty scales downward. Stipe characteristics also are useful for distinguishing these two species from other related species. In addition the incompletely reticulated basidiospores of these two species are also distinct from those of related species (i.e. S. foveatus). [ABSTRACT FROM AUTHOR]

We conducted line route censuses of fungal fruiting bodies from August to September in 2005 and 2006 along ridges and valleys and compared the differences in the encounter rates of fungal fruiting bodies (= fruiting bodies seen per census kilometer) between types of topography and between fungal functional groups (i.e., ectomycorrhizal and saprobic fungi) in warm temperate evergreen broad-leaved forests on Yakushima Island, Japan. We found 251 fungal fruiting bodies (26 families, 50 genera, and 65 species) in total, including 51 bodies from Tricholomataceae, 41 from Russulaceae, 25 from Boletaceae, and 19 from Amanitaceae. The encounter rate of ectomycorrhizal fungi was greater at the ridge route (26.7 unit/km) than at the valley route (8.7 unit/km) and that of saprobic fungi was greater at the valley route (25.0 unit/km) than at the ridge route (12.5 unit/km). In addition, we conducted 7-year intermittent sampling and identified 40 families, 96 genera, and 142 species. The topography-specific emergence pattern of the intermittent sampling method was similar to that of the line census method. The fungal species composition in this study was possibly affected by a topographic gradient for both fungal functional groups through soil moisture, nutrient availability, and host tree distribution. [ABSTRACT FROM AUTHOR]

Five new species of the Boletaceae (Agaricales) from Japan are described and illustrated: (1) Boletus bannaensis sp. nov. (section Luridi), forming a grayish-brown pileus and rufescent flesh, found in subtropical evergreen broad-leaved forests; (2) Leccinum rhodoporosum sp. nov., forming discolorous red pores, a whitish stipe covered overall with violet-brown to blackish-brown furfuraceous scales and fusoid-cylindrical brown basidiospores, found in subtropical evergreen broad-leaved forests or warm-temperate Quercus- Pinus forests; (3) Pulveroboletus brunneoscabrosus sp. nov., forming a lemon-yellow pulverulent basidiomata covered overall with orange to brownish-orange appressed scales, found in subtropical to warm temperate evergreen broad-leaved forests; (4) Rubinoboletus monstrosus sp. nov., forming a brownish-orange to yellowish-brown pileus and a very short, nonreticulate, hollow stipe, found in subtropical evergreen broad-leaved forests; and (5) Tylopilus fuligineoviolaceus sp. nov., having a deep violet to blackish-brown pileus and brunnescent hymenophore, found in warm temperate Quercus-Castanopsis forests. [ABSTRACT FROM AUTHOR]

Strobilomyces mirandus, a bolete new to Japan, is described and illustrated. This is the first record of the species outside of the type locality in Malaysia. It is very distinct from otherStrobilomycesspecies by the unusually colored yellow or golden-orange to brownish-orange of the basidiocarp. [ABSTRACT FROM AUTHOR]