How, not if, is the question mycologists should be asking about DNA-based typification.

Fungal metabarcoding of substrates such as soil, wood, and water is uncovering an unprecedented number of fungal species that do not seem to produce tangible morphological structures and that defy our best attempts at cultivation, thus falling outside the scope of the International Code of Nomenclature for algae, fungi, and plants. The present study uses the new, ninth release of the species hypotheses of the UNITE database to show that species discovery through environmental sequencing vastly outpaces traditional, Sanger sequencing-based efforts in a strongly increasing trend over the last five years. Our findings challenge the present stance of some in the mycological community - that the current situation is satisfactory and that no change is needed to "the code" - and suggest that we should be discussing not whether to allow DNA-based descriptions (typifications) of species and by extension higher ranks of fungi, but what the precise requirements for such DNA-based typifications should be. We submit a tentative list of such criteria for further discussion. The present authors hope for a revitalized and deepened discussion on DNA-based typification, because to us it seems harmful and counter-productive to intentionally deny the overwhelming majority of extant fungi a formal standing under the International Code of Nomenclature for algae, fungi, and plants.

Systemic infection of Bryoria (Lecanoromycetes, Ascomycota) by Athelia (Agaricomycetes, Basidiomycota) in western North America.

Bryoria (Parmeliaceae, Ascomycota) is one of the dominant genera of hair lichens in western North America and is characteristic of high-elevation conifer forest ecosystems. In areas where Bryoria is abundant, it is common to find thalli in which the thalline filaments become conglutinated, forming brittle dead zones. After sampling Bryoria thalli across western Canada and the northwestern United States at different times of the year, we found that this dieback phenomenon is associated with the winter growth of a mold-forming basidiomycete. We report that this fungus belongs to Athelia (Atheliaceae, Basidiomycota), a genus known to contain lichen pathogens, most notably A. arachnoidea. By sequencing a combination of genetic markers-nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS), partial nuc 28S rDNA (28S), and partial translation elongation factor 1-α (TEF1)-paired with morphometric analyses, we reveal the involvement of at least three additional lineages of lichen-associated Athelia and describe one as a new species, A. abscondita. Athelia abscondita is morphologically distinguished from other Athelia species by its basidia and basidiospores, was found to frequently infect members of Bryoria sect. Implexae, and was occasionally on other foliose and fruticose species within Parmeliaceae.

Systematic placement of Lagarobasidium cymosum and description of two new species.

Lagarobasidium cymosum is a rare corticioid species with characteristic morphology different from other Lagarobasidium species. We used nuc 5.8S rDNA, nuc 28S rDNA, and mt 12S rDNA loci to infer the phylogenetic position of L. cymosum. Our analyses suggest that it belongs to Xylodon but is not closely related to any of the other taxa referred to Lagarobasidium. Molecular and morphological information shows that the traditional concept of L. cymosum covers at least three species: Xylodon acuminatus from the Neotropics, X. cymosus from North America, and X. subtilissimus distributed in both Europe and North America. Lagarobasidium calongei is transferred to Xylodon, and DNA barcodes for Lyomyces incrustatus and Xylodon hjortstamii are published for the first time.

Significance of incongruent DNA loci in the taxonomy of wood-decaying Basidioradulum radula.

Modern taxonomic studies of Agaricomycetes rely on the integrative analyses of morphology, environmental data, geographic distribution, and usually several DNA loci. However, sampling and selection of DNA loci for the analyses are commonly shallow. In this study, we suggest minimal numbers of necessary specimens to sample and DNA loci to analyze in order to prevent inadequate taxonomic decisions in species groups with minor morphological and genealogical differences. We sampled four unlinked nuclear DNA gene regions (nuc rDNA ITS1-5.8S-ITS2, gh63, rpb2, and tef1) to revise the systematics of a common wood-decaying species Basidioradulum radula (Hymenochaetales) on an intercontinental set of specimens collected in the Northern Hemisphere. The DNA loci analyzed violate the genealogical concordance phylogenetic species recognition principles, thus confirming a single-species interpretation. We conclude that Hyphodontia syringae is a younger synonym of B. radula.

Morphological plasticity in brown-rot fungi: Antrodia is redefined to encompass both poroid and corticioid species.

Most known brown rot-producing species of Polyporales belong to the so-called "Antrodia clade" that largely consists of poroid species. In this study, we use three genetic markers to revise Antrodia s. str., the core group of this clade. We show that a corticioid species with a smooth hymenophore, Phlebia griseoflavescens, belongs to Antrodia s. str. Accordingly, we revise the generic concept of Antrodia s. str. to accommodate this species and two recently described poroid taxa, A. tenerifensis and A. multiformis. In addition, we describe two new poroid species within Antrodia s. str., A. latebrosa from Africa and A. peregrina from East Asia, and provide new documentation for the Southeast Asian species A. parvula based on recent collections from the type location.

Phylogeny and global diversity of Porodaedalea, a genus of gymnosperm pathogens in the Hymenochaetales.

Porodaedalea is a polypore genus of the Hymenochaetales that encompasses pathogens of conifer trees. In this study, we conduct a comprehensive study of the phylogeny and diversity of Porodaedalea based on collections and isolates from Europe, North America, North Africa, and Asia. Phylogenetic analysis of a two-gene data set, nuc ribosomal DNA internal transcribed spacers (ITS1-5.8S-ITS2 = ITS) and translation elongation factor 1-alpha (tef1), shows that 20 terminal clades that correspond to phylogenetic species well supported within Porodaedalea. Based on morphological evidence, five new species, P. alpicola, P. indica, P. kesiyae, P. microsperma, and P. yunnanensis, are described and illustrated. In addition, four still unnamed lineages are detected in North America and East Asia.

Studies in the Stypella vermiformis group (Auriculariales, Basidiomycota).

Stypella vermiformis is a heterobasidiomycete producing minute gelatinous basidiocarps on rotten wood of conifers in the Northern Hemisphere. In the current literature, Stypella papillata, the genus type of Stypella (described from Brazil), is treated as a taxonomic synonym of S. vermiformis. In the present paper, we revise the type material of S. papillata and a number of specimens addressed to S. vermiformis. As a result, the presumed synonymy of S. papillata and S. vermiformis is rejected and the genus Stypella is restricted to the single species S. papillata. Morphological and molecular phylogenetic studies of specimens from the Northern Hemisphere corresponding to the current concept of S. vermiformis uncovered three species from two newly described genera. S. vermiformis s.str. is distributed in temperate Europe and has small-sized basidia and basidiospores, and it is placed in a new genus, Mycostilla. Another genus, Stypellopsis, is created for two other species, the North American Stypellopsis farlowii, comb. nov., and the North European Stypellopsis hyperborea, sp. nov. Basidia and basidiospores of Stypellopsis spp. are larger than in Mycostilla vermiformis but other morphological characters are very similar. In addition, Spiculogloea minuta (Spiculogloeomycetes, Pucciniomycotina) is reported as new to Norway, parasitising basidiocarps of M. vermiformis and Tulasnella spp.

Additions to the taxonomy of Lagarobasidium and Xylodon (Hymenochaetales, Basidiomycota).

Lagarobasidium is a small genus of wood-decaying basidiomycetes in the order Hymenochaetales. Molecular phylogenetic analyses have either supported Lagarobasidium as a distinct taxon or indicated that it should be subsumed under Xylodon, a genus that covers the majority of species formerly placed in Hyphodontia. We used sequences from the ITS and nuclear LSU regions to infer the phylogenetic position of the type species L.detriticum. Analyses confirm Lagarobasidium as a synonym of Xylodon. Molecular and morphological information show that the traditional concept of L.detriticum covers at least two species, Xylodondetriticus from Europe and X.pruinosus with known distribution in Europe and North America. Three species currently placed in Lagarobasidium are transferred to Xylodon, viz. X.magnificus, X.pumilius and X.rickii. Three new Xylodon species are described and illustrated, X.ussuriensis and X.crystalliger from East Asia and X.attenuatus from the Pacific Northwest America. The identity of X.nongravis, described from Sri Lanka, is discussed.

Taxonomy and phylogeny of the Auriculariales (Agaricomycetes, Basidiomycota) with stereoid basidiocarps.

In the present study, we investigate taxonomy of the Auriculariales with effused or cupulate, persistent basidiocarps; generic and species concepts are revised based on morphological and DNA evidences. The genus Eichleriella is reinstated to embrace ten closely related species with ellipsoid-ovoid basidia, and the genus type, Eichleriella incarnata, is placed to the synonyms of Eichleriella leucophaea. Eichleriella bactriana, Eichleriella desertorum and Eichleriella sicca are described as new to science. In addition, four species earlier treated as members of Exidiopsis or Heterochaete are combined to the genus. The genus name Heteroradulum (type Radulum kmetii) is introduced for seven species with large, obconical, stipitate basidia. Of them, Heteroradulum adnatum and Heteroradulum semis are described as new. Two new genera, Amphistereum (with two species, type Eichleriella schrenkii) and Sclerotrema (monotypic, type Exidiopsis griseobrunnea), are proposed; Hirneolina (monotypic, type H. hirneoloides) and Tremellochaete (with two species, type Exidia japonica) are restored as good genera. The type species of Heterochaete, H. andina, is congeneric with Exidiopsis (type E. effusa).

Studies in the Antrodia serialis group (Polyporales, Basidiomycota).

Taxonomy and phylogeny of the Antrodia serialis group are revised with morphological, ecological, and geographic data, partial translation elongation factor 1-α (tef1) gene sequences, and nuc rDNA ITS1-5.8S-ITS2-28S sequences. The group contains 13 species found in boreal and temperate zones of the Northern Hemisphere. The species are limited to certain geographic areas within Eurasia and North America. The traditional morphology-based concept of A. serialis covers at least four closely related species: A. serialis s. str. in Eurasia, A. angusta, sp. nov., in East Asia, A. serrata, sp. nov., in the American Northeast, and A. calcitrosa, sp. nov., in the American Northwest. They all are associated mostly with Picea spp. and show small, but stable morphological differences from each other. In addition, A. morganii, comb. nov., inhabiting wood of Populus spp., occurs in North America, and Antrodia alaskana, comb. nov., a large-pored species, macroscopically similar to A. variiformis, is distributed along the Pacific coast of North America. The pine-dwelling A. flavimontis, sp. nov., similar to A. primaeva from Eurasia, is so far known only from the eastern part of the Rocky Mountains (Utah and Wyoming).

Polyozellus multiplex (Thelephorales) is a species complex containing four new species.

Geographic, morphological, and internal transcribed spacer (ITS)-based molecular review of collections identified as Polyozellus multiplex revealed that it is a complex of five phylogenetic species. Average spore size-either less or more than 7 × 6 µm-splits the complex into a small-spored group of two (P. multiplex and P. atrolazulinus) and a large-spored group of three (P. mariae, P. marymargaretae, and P. purpureoniger). Basidiocarps of the small-spored species are somewhat smaller than the large-spored ones, are various shades of blue, dark all the way to black, with brownish tomentum only in early growth, have dark context, and have pilei that tend to flare out at the edge. The large-spored species produce somewhat larger sporocarps, have light or lighter context than the pileipelis, and usually retain some brown on the mature pileipellis, the edge of which tends to curl like a cabbage leaf. All will darken or blacken with age. The species of the P. multiplex complex are distributed in the northern coniferous region, with the exception of Europe. One species (P. atrolazulinus) is known from three regions, eastern Asia, western North America, and northeastern North America. Two species are known from two regions: P. purpureoniger in eastern Asia and northwestern North America and P. multiplex in eastern Asia and eastern North America. Two species have been documented in one region only: P. mariae in northeastern North America and P. marymargaretae in western North America. A combination of location, macromorphology, and spore size will usually differentiate the species of the complex.

Species diversity in the Antrodia crassa group (Polyporales, Basidiomycota).

Antrodia is a polyphyletic genus, comprising brown-rot polypores with annual or short-lived perennial resupinate, dimitic basidiocarps. Here we focus on species that are closely related to Antrodia crassa, and investigate their phylogeny and species delimitation using geographic, ecological, morphological and molecular data (ITS and LSU rDNA, tef1). Phylogenetic analyses distinguished four clades within the monophyletic group of eleven conifer-inhabiting species (five described herein): (1)A. crassa s. str. (boreal Eurasia), Antrodia cincta sp. nova (North America) and Antrodia cretacea sp. nova (holarctic), all three being characterized by inamyloid skeletal hyphae that dissolve quickly in KOH solution; (2) Antrodia ignobilis sp. nova, Antrodia sitchensis and Antrodia sordida from North America, and Antrodia piceata sp. nova (previously considered conspecific with A. sitchensis) from Eurasia, possessing amyloid skeletal hyphae; (3) Antrodia ladiana sp. nova from the southern part of the USA, Antrodia pinea from East Asia, and Antrodia ferox - so far known from subtropical North America, but here reported also from Eurasia. These three species have inamyloid hyphae and narrow basidiospores; (4) the North American Antrodia pini-cubensis, sharing similar morphological characters with A. pinea, forming a separate clade. The habitat data indicate that several species are threatened by intensive forestry.

What is Antrodia sensu stricto?

The polypore genus Antrodia (Polyporales, Basidiomycota) in the strict sense consists of a small number of species grouped around the type species A. serpens in phylogenetic analyses. This distinct clade (Antrodia sensu stricto in our view) contains species of the Antrodia heteromorpha complex, A. macra coll. and Antrodia mappa (formerly Postia mappa). Nuclear rDNA ITS and tef1 data show that the Antrodia heteromorpha species complex includes four species: A. heteromorpha sensu stricto (mostly on gymnosperms, large pores and spores), A. serpens (on angiosperms in Europe, resupinate, smaller pores but large spores), A. favescens (smaller pores and spores, pileate species in North America, formerly known as Trametes sepium), and A. tanakai (a close kin of A. favescens in Eurasia). Antrodia albida is a synonym of A. heteromorpha sensu stricto. We combine A. mappa, A. favescens and A. tanakai in Antrodia and designate neotypes for A. albida and A. heteromorpha, and an epitype for A. serpens. We also compare the morphologically similar but distantly related A. albidoides and A. mellita, and conclude that A. macrospora and A. subalbidoides are synonyms of A. albidoides.