The interaction apparatus of Asteridiella callista (Meliolaceae, Ascomycota).

We document here for the first time ultrastructural details of the cellular interaction of Asteridiella callista and its host Stachytarpheta mutabilis var. violacea from Costa Rica. A. callista attaches to the host with appressoria, invades the epidermal cell wall and forms an apoplastic complex cisternal net, presumably for nutrient uptake from its host. This unique structure, called an interaction apparatus (Ia), consists of cisternae surrounded by a membrane continuous with the fungal cytoplasmic membrane. Subsequently the apoplastic trunk of the Ia extends into the host epidermal cell wall and contacts the host cytoplasmic membrane. Electron-opaque material, probably of fungal origin appears at the host cytoplasmic membrane. Finally these electron-opaque deposits are encased by host material. Functional and systematical aspects of this interaction scenario are discussed.

High genetic diversity at the regional scale and possible speciation in Sebacina epigaea and S. incrustans.

BACKGROUND: Phylogenetic studies, particularly those based on rDNA sequences from plant roots and basidiomata, have revealed a strikingly high genetic diversity in the Sebacinales. However, the factors determining this genetic diversity at higher and lower taxonomic levels within this order are still unknown. In this study, we analysed patterns of genetic variation within two morphological species, Sebacina epigaea and S. incrustans, based on 340 DNA haplotype sequences of independent genetic markers from the nuclear (ITS + 5.8S + D1/D2, RPB2) and mitochondrial (ATP6) genomes for 98 population samples. By characterising the genetic population structure within these species, we provide insights into species boundaries and the possible factors responsible for genetic diversity at a regional geographic scale. RESULTS: We found that recombination events are relatively common between natural populations within Sebacina epigaea and S. incrustans, and play a significant role in generating intraspecific genetic diversity. Furthermore, we also found that RPB2 and ATP6 genes display higher levels of intraspecific synonymous polymorphism. Phylogenetic and demographic analyses based on nuclear and mitochondrial loci revealed three distinct phylogenetic lineages within of each of the morphospecies S. epigaea and S. incrustans: one major and widely distributed lineage, and two geographically restricted lineages, respectively. We found almost no differential morphological or ecological characteristics that could be used to discriminate between these lineages. CONCLUSIONS: Our results suggest that recombination and negative selection have played significant roles in generating genetic diversity within these morphological species at small geographical scales. Concordance between gene genealogies identified lineages/cryptic species that have evolved independently for a relatively long period of time. These putative species were not associated with geographic provenance, geographic barrier, host preference or distinct phenotypic innovations.

Combined molecular and morphological data for improving phylogenetic hypothesis in Dacrymycetes.

We analyzed the DNA sequences of four gene regions, 28S and 18S rDNA, the ITS region and rpb2, to obtain a high resolution phylogenetic tree of Dacrymycetes. In addition, we comparatively studied micro- and macromorphological characteristics of representative species. The traditional generic classification based on morphological characteristics was not reflected by our molecular phylogenies. Ancestral state reconstructions indicated that the morphology of basidia and clamp connections are evolutionarily stable. In contrast, basidiocarps and basidiospore septation patterns appear variable. Dacrymyces unisporus shares the dolipores with non-perforate parenthesomes typical of other dacrymycetous taxa but is a unique species having predominantly non-bifurcate basidia and subglobose to ovoid basidiospores with transverse and longitudinal septa. In molecular phylogenies this species is a member of Dacrymycetes but always occupies a sister position in relation to the rest of the Dacrymycetes. Based on our results we propose a new genus, Unilacryma, for D. unisporus. For proper accommodation of this taxon, we introduce the family Unilacrymaceae and the order Unilacrymales.

Tracking the evolutionary history of Cortinarius species in section Calochroi, with transoceanic disjunct distributions.

BACKGROUND: Cortinarius species in section Calochroi display local, clinal and circumboreal patterns of distribution across the Northern Hemisphere where these ectomycorrhizal fungi occur with host trees throughout their geographical range within a continent, or have disjunct intercontinental distributions, the origins of which are not understood. We inferred evolutionary histories of four species, 1) C. arcuatorum, 2) C. aureofulvus, 3) C. elegantior and 4) C. napus, from populations distributed throughout the Old World, and portions of the New World (Central- and North America) based on genetic variation of 154 haplotype internal transcribed spacer (ITS) sequences from 83 population samples. By describing the population structure of these species across their geographical distribution, we attempt to identify their historical migration and patterns of diversification. RESULTS: Models of population structure from nested clade, demographic and coalescent-based analyses revealed genetically differentiated and geographically structured haplotypes in C. arcuatorum and C. elegantior, while C. aureofulvus showed considerably less population structure and C. napus lacked sufficient genetic differentiation to resolve any population structure. Disjunct populations within C. arcuatorum, C. aureofulvus and C. elegantior show little or no morphological differentiation, whereas in C. napus there is a high level of homoplasy and phenotypic plasticity for veil and lamellae colour. The ITS sequences of the type specimens of C. albobrunnoides and C. albobrunnoides var. violaceovelatus were identical to one another and are treated as one species with a wider range of geographic distribution under C. napus. CONCLUSIONS: Our results indicate that each of the Calochroi species has undergone a relatively independent evolutionary history, hypothesised as follows: 1) a widely distributed ancestral population of C. arcuatorum diverged into distinctive sympatric populations in the New World; 2) two divergent lineages in C. elegantior gave rise to the New World and Old World haplotypes, respectively; and 3) the low levels of genetic divergence within C. aureofulvus and C. napus may be the result of more recent demographic population expansions. The scenario of migration via the Bering Land Bridge provides the most probable explanation for contemporaneous disjunct geographic distributions of these species, but it does not offer an explanation for the low degree of genetic divergence between populations of C. aureofulvus and C. napus. Our findings are mostly consistent with the designation of New World allopatric populations as separate species from the European counterpart species C. arcuatorum and C. elegantior. We propose the synonymy of C. albobrunnoides, C. albobrunnoides var. violaceovelatus and C. subpurpureophyllus var. sulphureovelatus with C. napus. The results also reinforce previous observations that linked C. arcuatorum and C. aureofulvus displaying distributions in parts of North America and Europe. Interpretations of the population structure of these fungi suggest that host tree history has heavily influenced their modern distributions; however, the complex issues related to co-migration of these fungi with their tree hosts remain unclear at this time.

Competing sexual-asexual generic names in Agaricomycotina (Basidiomycota) with recommendations for use.

With the change to one scientific name for fungal taxa, generic names typified by species with sexual or asexual morph types are being evaluated to determine which names represent the same genus and thus compete for use. In this paper generic names of the Agaricomycotina (Basidiomycota) were evaluated to determine synonymy based on their type. Forty-seven sets of sexually and asexually typified names were determined to be congeneric and recommendations are made for which generic name to use. In most cases the principle of priority is followed. However, 16 generic names are recommended for use that do not have priority and thus need to be protected: Aleurocystis over Matula; Armillaria over Acurtis and Rhizomorpha; Asterophora over Ugola; Botryobasidium over Acladium, Allescheriella, Alysidium, Haplotrichum, Physospora, and Sporocephalium; Coprinellus over Ozonium; Coprinopsis over Rhacophyllus; Dendrocollybia over Sclerostilbum and Tilachlidiopsis; Diacanthodes over Bornetina; Echinoporia over Echinodia; Neolentinus over Digitellus; Postia over Ptychogaster; Riopa over Sporotrichum; Scytinostroma over Artocreas, Michenera, and Stereofomes; Tulasnella over Hormomyces; Typhula over Sclerotium; and Wolfiporia over Gemmularia and Pachyma. Nine species names are proposed for protection: Botryobasidium aureum, B. conspersum, B. croceum, B. simile, Pellicularia lembosporum (syn. B. lembosporum), Phanerochaete chrysosporium, Polyporus metamorphosus (syn. Riopa metamorphosa), Polyporus mylittae (syn. Laccocephalum mylittae), and Polyporus ptychogaster (syn. Postia ptychogaster). Two families are proposed for protection: Psathyrellaceae and Typhulaceae. Three new species names and 30 new combinations are established, and one lectotype is designated.

Diverging diversity patterns in the Tulasnella (Basidiomycota, Tulasnellales) mycobionts of Aneura pinguis (Marchantiophyta, Metzgeriales) from Europe and Ecuador.

Aneura pinguis (Aneuraceae) is a cosmopolitan thalloid liverwort that shows a specific mycorrhiza-like interaction with basidiomycetes. To date, tropical specimens have not been studied in great depth. Samples of A. pinguis were collected from 48 individuals in one plot in South Ecuador and 54 individuals in five European countries. Light and transmission electron microscopy and molecular analyses based on nuclear rDNA coding for the ribosomal large subunit (nucLSU) and from the 5.8s-ITS2 regions were carried out to identify the associated mycobionts and to study their phylogenetic relationships. Microscopic and ultrastructural investigations of the fungal colonisation showed a high congruence between the European and the Ecuadorian sites and confirmed previous results. Tulasnellales are the only mycobionts that could be detected from ultrastructural characters with certainty. Molecular phylogenetic analysis indicated the presence of tulasnelloid fungi from at least 13 distinct clades. The composition of the communities of tulasnelloid fungi in A. pinguis differs between Ecuador and Europe. The diversity of tulasnelloid fungal partners was much higher at the Ecuadorian site.

Phylogenetic relationships in Cortinarius, section Calochroi, inferred from nuclear DNA sequences.

BACKGROUND: Section Calochroi is one of the most species-rich lineages in the genus Cortinarius (Agaricales, Basidiomycota) and is widely distributed across boreo-nemoral areas, with some extensions into meridional zones. Previous phylogenetic studies of Calochroi (incl. section Fulvi) have been geographically restricted; therefore, phylogenetic and biogeographic relationships within this lineage at a global scale have been largely unknown. In this study, we obtained DNA sequences from a nearly complete taxon sampling of known species from Europe, Central America and North America. We inferred intra- and interspecific phylogenetic relationships as well as major morphological evolutionary trends within section Calochroi based on 576 ITS sequences, 230 ITS + 5.8S + D1/D2 sequences, and a combined dataset of ITS + 5.8S + D1/D2 and RPB1 sequences of a representative subsampling of 58 species. RESULTS: More than 100 species were identified by integrating DNA sequences with morphological, macrochemical and ecological data. Cortinarius section Calochroi was consistently resolved with high branch support into at least seven major lineages: Calochroi, Caroviolacei, Dibaphi, Elegantiores, Napi, Pseudoglaucopodes and Splendentes; whereas Rufoolivacei and Sulfurini appeared polyphyletic. A close relationship between Dibaphi, Elegantiores, Napi and Splendentes was consistently supported. Combinations of specific morphological, pigmentation and molecular characters appear useful in circumscribing clades. CONCLUSION: Our analyses demonstrate that Calochroi is an exclusively northern hemispheric lineage, where species follow their host trees throughout their natural ranges within and across continents. Results of this study contribute substantially to defining European species in this group and will help to either identify or to name new species occurring across the northern hemisphere. Major groupings are in partial agreement with earlier morphology-based and molecular phylogenetic hypotheses, but some relationships were unexpected, based on external morphology. In such cases, their true affinities appear to have been obscured by the repeated appearance of similar features among distantly related species. Therefore, further taxonomic studies are needed to evaluate the consistency of species concepts and interpretations of morphological features in a more global context. Reconstruction of ancestral states yielded two major evolutionary trends within section Calochroi: (1) the development of bright pigments evolved independently multiple times, and (2) the evolution of abruptly marginate to flattened stipe bulbs represents an autapomorphy of the Calochroi clade.

Cystobasidiopsis nirenbergiae, a new agaricostilbomycete (Pucciniomycotina).

A new genus, Cystobasidiopsis, and a new species, Cystobasidiopsis nirenbergiae, are described for a fungus isolated from an arable loess soil in Ahlum near Braunschweig, Niedersachsen, Germany. An integrated analysis of morphological, ecological, ultrastructural and molecular data indicates that the new species belongs to the Chionosphaeraceae within the Agaricostilbales. Relevant characteristics of the new species are discussed and compared with those of related taxa.

Implications of molecular characters for the phylogeny of the Microbotryaceae (Basidiomycota: Urediniomycetes).

BACKGROUND: Anther smuts of the basidiomycetous genus Microbotryum on Caryophyllaceae are important model organisms for many biological disciplines. Members of Microbotryum are most commonly found parasitizing the anthers of host plants in the family Caryophyllaceae, however they can also be found on the anthers of members of the Dipsacaceae, Lamiaceae, Lentibulariaceae, and Portulacaceae. Additionally, some members of Microbotryum can be found infecting other organs of mainly Polygonaceae hosts. Based on ITS nrDNA sequences of members of almost all genera in Microbotryaceae, this study aims to resolve the phylogeny of the anther smuts and their relationship to the other members of the family of plant parasites. A multiple analysis strategy was used to correct for the effects of different equally possible ITS sequence alignments on the phylogenetic outcome, which appears to have been neglected in previous studies. RESULTS: The genera of Microbotryaceae were not clearly resolved, but alignment-independent moderate bootstrap support was achieved for a clade containing the majority of the Microbotryum species. The anther parasites appeared in two different well-supported lineages whose interrelationship remained unresolved. Whereas bootstrap support values for some clades were highly vulnerable to alignment conditions, other clades were more robustly supported. The differences in support between the different alignments were much larger than between the phylogenetic optimality criteria applied (maximum parsimony and maximum likelihood). CONCLUSION: The study confirmed, based on a larger dataset than previous work, that the anther smuts on Caryophyllaceae are monophyletic and that there exists a native North American group that diverged from the European clade before the radiation of the European species. Also a second group of anther smuts was revealed, containing parasites on Dipsacaceae, Lamiaceae, and Lentibulariaceae. At least the majority of the parasites of Asteraceae appeared as a monophylum, but delimitations of some species in this group should be reconsidered. Parasitism on Polygonaceae is likely to be the ancestral state for the Microbotryaceae on Eudicot hosts.

Two new pycnidial members of the Atractiellales: Basidiopycnis hyalina and Proceropycnis pinicola.

Two new genera, Basidiopycnis and Proceropycnis, and two new species, Basidiopycnis hyalina and Proceropycnis pinicola, are described. An integrated analysis of morphological, ecological, ultrastructural and molecular data indicates that the new taxa belong to the Atractiellales. Relevant characteristics of the new genera and species are discussed and compared with those of related taxa.

An overview of the higher level classification of Pucciniomycotina based on combined analyses of nuclear large and small subunit rDNA sequences.

In this study we provide a phylogenetically based introduction to the classes and orders of Pucciniomycotina (= Urediniomycetes), one of three subphyla of Basidiomycota. More than 8000 species of Pucciniomycotina have been described including putative saprotrophs and parasites of plants, animals and fungi. The overwhelming majority of these (approximately 90%) belong to a single order of obligate plant pathogens, the Pucciniales (= Uredinales), or rust fungi. We have assembled a dataset of previously published and newly generated sequence data from two nuclear rDNA genes (large subunit and small subunit) including exemplars from all known major groups in order to test hypotheses about evolutionary relationships among the Pucciniomycotina. The utility of combining nuc-lsu sequences spanning the entire D1-D3 region with complete nuc-ssu sequences for resolution and support of nodes is discussed. Our study confirms Pucciniomycotina as a monophyletic group of Basidiomycota. In total our results support eight major clades ranked as classes (Agaricostilbomycetes, Atractiellomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Microbotryomycetes, Mixiomycetes and Pucciniomycetes) and 18 orders.

Divergence Times and Phylogenetic Patterns of Sebacinales, a Highly Diverse and Widespread Fungal Lineage.

Patterns of geographic distribution and composition of fungal communities are still poorly understood. Widespread occurrence in terrestrial ecosystems and the unique richness of interactions of Sebacinales with plants make them a target group to study evolutionary events in the light of nutritional lifestyle. We inferred diversity patterns, phylogenetic structures and divergence times of Sebacinales with respect to their nutritional lifestyles by integrating data from fossil-calibrated phylogenetic analyses. Relaxed molecular clock analyses indicated that Sebacinales originated late Permian within Basidiomycota, and their split into Sebacinaceae and Serendipitaceae nom. prov. likely occurred during the late Jurassic and the early Cretaceous, coinciding with major diversifications of land plants. In Sebacinaceae, diversification of species with ectomycorrhizal lifestyle presumably started during the Paleocene. Lineage radiations of the core group of ericoid and cavendishioid mycorrhizal Sebacinales started probably in the Eocene, coinciding with diversification events of their hosts. The diversification of Sebacinales with jungermannioid interactions started during the Oligocene, and occurred much later than the diversification of their hosts. Sebacinales communities associated either with ectomycorrhizal plants, achlorophyllous orchids, ericoid and cavendishioid Ericaceae or liverworts were phylogenetically clustered and globally distributed. Major Sebacinales lineage diversifications started after the continents had drifted apart. We also briefly discuss dispersal patterns of extant Sebacinales.

Mycosarcoma (Ustilaginaceae), a resurrected generic name for corn smut (Ustilago maydis) and its close relatives with hypertrophied, tubular sori.

Ustilago is a polyphyletic genus of smut fungi found mainly on Poaceae. The development of a taxonomy that reflects phylogeny requires subdivision of Ustilago into smaller monophyletic genera. Several separate systematic analyses have determined that Macalpinomyces mackinlayi, M. tubiformis, Tolyposporella pachycarpa, Ustilago bouriquetii and U. maydis, occupy a unique phylogenetic position within the Ustilaginaceae. A previously introduced monotypic generic name typified by U. maydis, Mycosarcoma, is available to accommodate these species, which resolves one component of polyphyly for Ustilagos.lat. in Ustilaginaceae. An emended description of Mycosarcoma is provided to reflect the morphological synapomorphies of this monophyletic group. A specimen of Ustilago maydis that has had its genome sequenced is designated as a neotype for this species. Taxonomic stability will further be provided by a forthcoming proposal to conserve the name Uredo maydis over Lycoperdon zeae, which has priority by date, in order to preserve the well-known epithet maydis.

On the Evolutionary History of Uleiella chilensis, a Smut Fungus Parasite of Araucaria araucana in South America: Uleiellales ord. nov. in Ustilaginomycetes.

The evolutionary history, divergence times and phylogenetic relationships of Uleiella chilensis (Ustilaginomycotina, smut fungi) associated with Araucaria araucana were analysed. DNA sequences from multiple gene regions and morphology were analysed and compared to other members of the Basidiomycota to determine the phylogenetic placement of smut fungi on gymnosperms. Divergence time estimates indicate that the majority of smut fungal orders diversified during the Triassic-Jurassic period. However, the origin and relationships of several orders remain uncertain. The most recent common ancestor between Uleiella chilensis and Violaceomyces palustris has been dated to the Lower Cretaceous. Comparisons of divergence time estimates between smut fungi and host plants lead to the hypothesis that the early Ustilaginomycotina had a saprobic lifestyle. As there are only two extant species of Araucaria in South America, each hosting a unique Uleiella species, we suggest that either coevolution or a host shift followed by allopatric speciation are the most likely explanations for the current geographic restriction of Uleiella and its low diversity. Phylogenetic and age estimation analyses, ecology, the unusual life-cycle and the peculiar combination of septal and haustorial characteristics support Uleiella chilensis as a distinct lineage among the Ustilaginomycotina. Here, we describe a new ustilaginomycetous order, the Uleiellales to accommodate Uleiella. Within the Ustilaginomycetes, Uleiellales are sister taxon to the Violaceomycetales.

Entorrhizomycota: A New Fungal Phylum Reveals New Perspectives on the Evolution of Fungi.

Entorrhiza is a small fungal genus comprising 14 species that all cause galls on roots of Cyperaceae and Juncaceae. Although this genus was established 130 years ago, crucial questions on the phylogenetic relationships and biology of this enigmatic taxon are still unanswered. In order to infer a robust hypothesis about the phylogenetic position of Entorrhiza and to evaluate evolutionary trends, multiple gene sequences and morphological characteristics of Entorrhiza were analyzed and compared with respective findings in Fungi. In our comprehensive five-gene analyses Entorrhiza appeared as a highly supported monophyletic lineage representing the sister group to the rest of the Dikarya, a phylogenetic placement that received but moderate maximum likelihood and maximum parsimony bootstrap support. An alternative maximum likelihood tree with the constraint that Entorrhiza forms a monophyletic group with Basidiomycota could not be rejected. According to the first phylogenetic hypothesis, the teliospore tetrads of Entorrhiza represent the prototype of the dikaryan meiosporangium. The alternative hypothesis is supported by similarities in septal pore structure, cell wall and spindle pole bodies. Based on the isolated phylogenetic position of Entorrhiza and its peculiar combination of features related to ultrastructure and reproduction mode, we propose a new phylum Entorrhizomycota, for the genus Entorrhiza, which represents an apparently widespread group of inconspicuous fungi.

A light- and electron-microscopic study on a vesicular-arbuscular host-fungus interaction in gametophytes and young sporophytes of the Gleicheniaceae (Filicales).

Gametophytes and primary roots of young sporophytes of the Gleicheniaceae were studied by means of light- and electron microscopy. An aseptate fungus invaded the gametophyte tissue through the rhizoids. The fungus spread within the thickened midrib forming intracellular hyphal coils. The latter gave rise regularly to arbuscules which were cytoplasmic in the young part of the midrib. In the older midrib, arbuscules degenerated and vesicles occurred. With arbuscular development, host cytoplasm and cell organelles increased and starch disappeared from plastids. The fungus formed globose spores inside the rhizoids. The gametophyte fungus did not transverse the gametophyte- sporophyte junction. Primary roots shorter than 2 mm were not infected. Primary roots longer than 2 mm showed vesicular-arbuscular mycorrhiza with a completely intracellular development of the fungus.

Molecular diversity of arbuscular mycorrhizal fungi in Prunus africana, an endangered medicinal tree species in dry Afromontane forests of Ethiopia.

• The molecular diversity of arbuscular mycorrhizal (AM) fungi colonizing roots of Prunus africana and of AM fungal spores obtained from baiting cultures of indigenous soils from two dry afromontane forests of Ethiopia was investigated. • The internal transcribed spacer (ITS) rDNA region from colonized roots and single spores of three AM fungal spore types was amplified, cloned and sequenced using AM fungal specific primers. • Phylogenetic analysis using the 5.8S rDNA data set revealed that 109 of the sequences obtained belong to members of the Glomeromycota. Subsequent 5.8S/ITS2 rDNA sequence analysis indicated high AM fungal diversity and dominance of Glomus types. Twenty sequence types belonged to the Glomeraceae and one each to the Diversisporaceae and Archaeosporaceae. Two of the three spore types were identified as Glomus etunicatum and Glomus mosseae. • Twenty of the AM fungal types identified are new to Ethiopia and to science. The AM fungal community differed between the two sites studied.

Amauromyces farinaceous, rare known species and new record from Taiwan.

Amauromyces farinaceous is investigated. The species is a rare corticiaceous Homobasidiomycete recently collected in Taiwan. The unique basidial morphology, cell walls and septal pores of the hyphae are studied by transmission electron microscopy. The study demonstrates the gradual thickening of cell walls in the lower parts of young basidia, leaving only a small asymmetric cytoplasmic channel in mature stages. Systematics of genus Amauromyces are discussed by comparing it with Athelia, Athelopsis, Chaetoderma, Columnocystis, Gloeosoma, Paullicorticium, Sistotremastrum, Trechispora, Tulasnella and Veluticeps.

Tuberculina-rusts: a unique basidiomycetous interfungal cellular interaction with horizontal nuclear transfer.

Cellular interaction of the basidiomycete Tuberculina persicina with the haploid stages of two rusts Puccinia silvatica and Tranzschelia pruni-spinosae was analyzed by serial-section electron microscopy of chemically fixed samples and samples subjected to high-pressure freezing and freeze substitution. Tuberculina persicina is a contact parasite, forming neither haustoria nor other intracellular structures. However, at contact areas between T. persicina and its hosts, distinct interfungal interactions are present. At the beginning, a hyphal cell of T. persicina invades the host cell wall with a protuberance and the cell walls of both protuberance and host cell dissolve at the point of contact. Thus, the plasma membranes of the two organisms contact and fuse to form a pore that enlarges to a final diameter of approximately 1 µm. The membrane of the fusion pore is continuous with the plasma membranes of both cells, and Tuberculina nuclei and other organelles are transferred to the rust cells. Phylogenetic and functional aspects of this curious basidiomycetous interfungal interaction are discussed, and a hypothesis of the evolutionary derivation of the Tuberculina mycoparasitism from a sexual interaction is presented.

Heterorepetobasidium, a new genus in the Auriculariales.

A new genus, Heterorepetobasidium, is proposed to accommodate two new species, H. subglobosum and H. ellipsoideum, recently collected in Taiwan. These species have apically, partially septate basidia, strongly swollen sterigmata, and repetobasidia. The systematics of the new taxa and related ones, inclusive of Ceratobasidium and the Ceratobasidiaceae, are reinterpreted.