This article is the 19th contribution to the fungal diversity notes series, in which 106 taxa distributed in 3 phyla, 11 classes, 35 orders, and 64 families are treated. Taxa described in the present study include a new family, 5 new genera, 69 new species, 3 new combinations, 25 new host, habitat, and geographical records, a new name, a new collection, as well as reinstating a previously suppressed genus. The newly established family is Parasporidesmiaceae and the five new genera described herein are Dematiodidymosporum, Neoacrogenospora, Parasporidesmium, Speluncomyces, and Uniomyces. The 69 new species are Acrocalymma triseptatum, Agaricus darjeelingensis, Annellophorella aquatica, Anteaglonium menghaiense, Balsamia microspora, Bambusicola dehongensis, Barriopsis menglaense, Benjaminiomyces bergonzoi, Camporesiomyces aquaticus, Camporesiomyces wurfbainiae, Cercospora palmata, Chrysomphalina cantharella, Colletotrichum heteropanacicola, Conioscypha guizhouensis, Conioscypha yadongensis, Cora dalfornoae, Cylindromonium brasiliense, Dematiodidymosporum aquaticum, Distoseptispora dinghuensis, Distoseptispora zunyiensis, Ebollia neocarnea, Eudimeromyces aequatorialis, Eudimeromyces euconni, Funalia indica, Fuscosporella ovalis, Fuscosporella yunnanensis, Halobasidium csapodyae, Halokirschsteiniothelia hunanensis, Hongkongmyces xishuangbannaensis, Inocybe ispartaensis, Laboulbenia neofrancoisiana, Lachnella kunmingensis, Lasmenia thailandica, Leptospora cannabini, Lycoperdon sridharii, Myxospora neomasonii, Natipusilla aquatica, Neoacrogenospora aquatica, Neomassaria sinensis, Neovaginatispora juglandis, Niesslia yunnanensis, Ophiocordyceps aseptatospora, Oxneriaria sheosarensis, Paramicrosphaeropsis vitis, Paramyrothecium strychni, Parapaucispora aquatica, Parasporidesmium aquaticum, Parmelia neosaxatilis, Periconia bambusicola, Periconia neohongheensis, Peroneutypa thailandica, Polyozellus albus, Porina magnoliae, Porostereum subspadiceum, Pseudosperma subvolvatum, Pseudothyridariella caseariae, Rhexocercosporidium ferulae, Russula rubroglutinata, Septoriella iranica, Seriascoma asexuale, Sesquicillium flavum, Sirastachys zhongkaiensis, Speluncomyces lunatus, Sporidesmiella yunnanensis, Striaticonidium xishuangbannaensis, Trametopsis indica, Tulostoma hyderabadensis, Uniomyces hakkeijimanus, and Virgaria guizhouensis. The three new combinations are Lycoperdon alpinum, Lycoperdon lloydii, and Lycoperdon macrogemmae. The 25 new records comprise Acremonium sclerotigenum, Agroathelia rolfsii, Alfaria terrestris, Aspergillus cejpii, Colletotrichum brevisporum, Coriolopsis brunneoleuca, Coriolopsis hainanensis, Cytospora tamaricicola, Fomitopsis malicola, Fulvifomes fastuosus, Fulvifomes thailandicus, Funalia cystidiata, Funalia subgallica, Longididymella vitalbae, Lopharia mirabilis, Metarhizium viridulum, Neopestalotiopsis haikouensis, Occultibambusa aquatica, Phaeoacremonium scolyti, Phaeocytostroma virdimurae, Puccinia mysuruensis, Rhizopus stolonifer, Serpula similis, Trametes ellipsospora, and Vamsapriya shiwandashanensis. In addition, the new name is Irpiciporus pseudoxuchilensis, and the new collection is Aspergillus sydowii. The previously suppressed genus Eudimeromyces has been taxonomically reinstated.

Piloderma constitutes a small genus of soft, corticioid, ectomycorrhizal, widely distributed and mostly very common species. Microscopically, its members have traditionally been recognised by their simple-septate hyphae and by their small, thick-walled, colourless to pale yellow spores. We describe five new species from northern Europe based on molecular and morphological data: P. frondosum sp. nov., P. fugax sp. nov., P. lamprolithum sp. nov., P. luminosum sp. nov. and P. mirabile sp. nov. All the new species, except P. luminosum seem to be more or less rare. Piloderma fugax has a strong preference for old-growth forest - a lifestyle seemingly deviating from the rest of the genus. Piloderma mirabile is a sister species to P. sphaerosporum and the first known species with clamped hyphae. Piloderma lamprolithum is closely related to P. exiguum and distinguished by its large encrusting crystals. Piloderma luminosum is very closely related to, and morphologically semicryptic with, P. byssinum. To clarify its distinction from P. byssinum, an epitype is designated for the latter. Piloderma frondosum also belongs to the P. byssinum cluster and is distinguished by its association to broadleaved trees. An updated key to all Piloderma species is provided.

Journal impact factors were devised to qualify and compare university library holdings but are frequently repurposed for use in ranking applications, research papers, and even individual applicants in mycology and beyond. The widely held assumption that mycological studies published in journals with high impact factors add more to systematic mycology than studies published in journals without high impact factors nevertheless lacks evidential underpinning. The present study uses the species hypothesis system of the UNITE database for molecular identification of fungi and other eukaryotes to trace the publication history and impact factor of sequences uncovering new fungal species hypotheses. The data show that journal impact factors are poor predictors of discovery potential in systematic mycology. There is no clear relationship between journal impact factor and the discovery of new species hypotheses for the years 2000–2021. On the contrary, we found journals with low, and even no, impact factor to account for substantial parts of the species hypothesis landscape, often discovering new fungal taxa that are only later picked up by journals with high impact factors. Funding agencies and hiring committees that insist on upholding journal impact factors as a central funding and recruitment criterion in systematic mycology should consider using indicators such as research quality, productivity, outreach activities, review services for scientific journals, and teaching ability directly rather than using publication in high impact factor journals as a proxy for these indicators.

In this article we merge the genus Tomentella with Thelephora. As a result, 191 new combinations are made and 24 nomina nova are created. In addition, one new combination of Tomentellopsis and Polyozellus species are made, respectively.

Basidiomycota is one of the major phyla in the fungal tree of life. The outline of Basidiomycota provides essential taxonomic information for researchers and workers in mycology. In this study, we present a time-framed phylogenomic tree with 487 species of Basidiomycota from 127 families, 47 orders, 14 classes and four subphyla; we update the outline of Basidiomycota based on the phylogenomic relationships and the taxonomic studies since 2019; and we provide notes for each order and discuss the history, defining characteristics, evolution, justification of orders, problems, significance, and plates. Our phylogenomic analysis suggests that the subphyla diverged in a time range of 443–490 Myr (million years), classes in a time range of 312–412 Myr, and orders in a time range of 102–361 Myr. Families diverged in a time range of 50–289 Myr, 76–224 Myr, and 62–156 Myr in Agaricomycotina, Pucciniomycotina, and Ustilaginomycotina, respectively. Based on the phylogenomic relationships and divergence times, we propose a new suborder Mycenineae in Agaricales to accommodate Mycenaceae. In the current outline of Basidiomycota, there are four subphyla, 20 classes, 77 orders, 297 families, and 2134 genera accepted. When building a robust taxonomy of Basidiomycota in the genomic era, the generation of molecular phylogenetic data has become relatively easier. Finding phenotypical characters, especially those that can be applied for identification and classification, however, has become increasingly challenging.

Fungal metabarcoding of substrates such as soil, wood, and water are 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 of the ambit 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 the mycological community – that “the code” works fine and that these complications will somehow sort themselves out given enough time and a following wind – 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. However, the present authors fear that no waves of change will be lapping the shores of mycology for the foreseeable future, leaving the overwhelming majority of extant fungi without formal names and thus scientific and environmental agency. It is not clear to us who benefits from that, but neither fungi nor mycology are likely to be on the winning side.

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.

Amaurodon (Thelephorales, Basidiomycota) constitutes a small but globally distributed genus in the order Thelephorales that is thought to be saprotrophic. Previously described species are soft and corticioid, with a smooth or hydnoid, blue to green hymenitun which turns green after drying and have spores that turn purple in KOH. Based on sequences from the nuclear rDNA regions ITS1-5.8S-ITS2 (ITS) and 28S Amaurodon caeruleocaseus is described from Western Australia a species that has all the morphological features common to the genus, with the interesting exception of forming a stipitate basidiome with a marshmallow-like consistency. Its closest relative is shown to be A. mustialaensis. The two species are unique within Thelephorales in having spores that appear smooth rather than ornamented illider a light microscope. A key to the genus Amaumdon is a Iso provided.

One Tomentella and two Pseudotomentella species are described from alpine areas of Sweden and Norway. Tomentella viridibasidia sp. nov. is genetically closely related to T. bryophila, but is morphologically most similar to T. olivascens and T. stuposa. Pseudotomentella badjelanndana sp. nov. and P. sorjusensis sp. nov. belong to the P. tristis group. At least P. sorjusensis must currently be regarded as morphologically cryptic with P. rotundispora. Basidiomata of the new species have only been encountered in the Scandes Mountains, but root-tip and soil sequences indicate that all three are geographically widespread. An updated key to the Pseutomentella tristis group is provided.

Aquatic fungi are a largely unexplored group of organisms with a still unknown diversity of ecological niches. Groundwater biomes comprise vast but poorly explored habitats. In this study, we sampled the Icelandic groundwater, a unique system that has been separated and isolated into distinct basins for millions of years due to volcanic activity. The aim was to explore the fungal diversity of the basins and its connection with the surface waters. We screened the DNA-based fungal diversity of 11 Icelandic groundwater springs and their emerging surface waters by ITS metabarcoding, revealing that the species turnover was indeed distinct for each groundwater basin. Furthermore, the groundwater taxa, which include many psychrophilic yeast-like and ascomycete fungi, seem to serve as a constant inoculum for the surface water. Nevertheless, the groundwater springs had a lower sequence proportion of early diverging, primary aquatic fungal lineages (10%) and completely unknown lineages (13%) than the surface waters (41% and 22%, respectively), likely explained by the lower diversity of suitable hosts for these presumed parasitic lineages. Our results highlight the importance of overlooked organism groups in the resolution of overarching research questions in ecology, nutrient circulation, and global change biology at large.

Svensk sammanfattning Publications ..........................................................................................................................

P.tristisis an ectomycorrhizal, corticioid fungus whose name is frequently assigned to collections of basidiomata as well as root tip and soil samples from a wide range of habitats and hosts across the northern hemisphere. Despite this, its identity is unclear; eight heterotypic taxa have in major reviews of the species been considered synonymous with or morphologically similar toP.tristis, but no sequence data from type specimens have been available.With the aim to clarify the taxonomy, systematics, morphology, ecology and geographical distribution ofP.tristisand its morphologically similar species, we studied their type specimens as well as 147 basidiomata collections of mostly North European material.We used gene trees generated in BEAST 2 and PhyML and species trees estimated in STACEY and ASTRAL to delimit species based on the ITS, LSU, Tef1α and mtSSU regions. We enriched our sampling with environmental ITS sequences from the UNITE database.We found theP.tristisgroup to contain 13 molecularly and morphologically distinct species. Three of these,P.tristis,P.umbrinaandP.atrofusca, are already known to science, while ten species are here described as new:P.sciastrasp. nov.,P.tristoidessp. nov.,P.umbrinascenssp. nov.,P.pinophilasp. nov.,P.alnophilasp. nov.,P.alobatasp. nov.,P.plurilobasp. nov.,P.abundilobasp. nov.,P.rotundisporasp. nov.andP.mediasp. nov.We discoveredP.rhizopunctataandP.atrofuscato form a sister clade to all other species inP.tristiss.l. These two species, unlike all other species in theP.tristiscomplex, are dimitic.In this study, we designate epitypes forP.tristis,P.umbrinaandHypochnopsisfuscataand lectotypes forAuriculariaphylacterisandThelephorabiennis. We show that the holotype ofHypochnussitnensisand the lectotype ofHypochnopsisfuscataare conspecific withP.tristis, but in the absence of molecular information we regardPseudotomentellalongisterigmataandHypochnusrhacodiumas doubtful taxa due to their aberrant morphology. We confirmA.phylacteris,TomentellabiennisandSeptobasidiumarachnoideumas excluded taxa, since their morphology clearly show that they belong to other genera. A key to the species of theP.tristisgroup is provided.We foundP.umbrinato be a common species with a wide, Holarctic distribution, forming ectomycorrhiza with a large number of host species in habitats ranging from tropical forests to the Arctic tundra. The other species in theP.tristisgroup were found to be less common and have narrower ecological niches.

Species occurrence records from online databases are an indispensable resource in ecological, biogeographical and palaeontological research. However, issues with data quality, especially incorrect geo‐referencing or dating, can diminish their usefulness. Manual cleaning is time‐consuming, error prone, difficult to reproduce and limited to known geographical areas and taxonomic groups, making it impractical for datasets with thousands or millions of records. Here, we present CoordinateCleaner, an r‐package to scan datasets of species occurrence records for geo‐referencing and dating imprecisions and data entry errors in a standardized and reproducible way. CoordinateCleaner is tailored to problems common in biological and palaeontological databases and can handle datasets with millions of records. The software includes (a) functions to flag potentially problematic coordinate records based on geographical gazetteers, (b) a global database of 9,691 geo‐referenced biodiversity institutions to identify records that are likely from horticulture or captivity, (c) novel algorithms to identify datasets with rasterized data, conversion errors and strong decimal rounding and (d) spatio‐temporal tests for fossils. We describe the individual functions available in CoordinateCleaner and demonstrate them on more than 90 million occurrences of flowering plants from the Global Biodiversity Information Facility (GBIF) and 19,000 fossil occurrences from the Palaeobiology Database (PBDB). We find that in GBIF more than 3.4 million records (3.7%) are potentially problematic and that 179 of the tested contributing datasets (18.5%) might be biased by rasterized coordinates. In PBDB, 1205 records (6.3%) are potentially problematic. All cleaning functions and the biodiversity institution database are open‐source and available within the CoordinateCleaner r‐package.

DNA sequences from the nuclear LSU and ITS regions were used for phylogenetic analyses of Thelephorales with a focus on the stipitate hydnoid genera Hydnellum and Sarcodon. Analyses showed that Hydnellum and Sarcodon are distinct genera but that the current division, based on basidioma texture, makes Sarcodon paraphyletic with respect to Hydnellum. In order to make genera monophyletic several species are moved from Sarcodon to Hydnellum and the following new combinations are made: Hydnellumamygdaliolens, H.fennicum, H.fuligineoviolaceum, H.fuscoindicum, H.glaucopus, H.joeides, H.lepidum, H.lundellii, H.martioflavum, H.scabrosum, H.underwoodii, and H.versipelle. Basidiospore size seems to separate the genera in most cases. Hydnellum species have basidiospore lengths in the range 4.45-6.95 µm while the corresponding range for Sarcodon is 7.4-9 µm. S.quercinofibulatus deviates from this pattern with an average spore length around 6 µm. Neotropical Sarcodon species represent a separate evolutionary lineage.