Specimens of Candolleomyces from tropical and subtropical regions, mainly the Dominican Republic, the Caribbean, Central America, and southern USA, were analyzed morphologically and molecularly. Historical fungarium types and sequences from Africa, Asia, and the Americas were included. ITS sequences from ancient collections were obtained via Illumina when Sanger sequencing failed. Phylogenetic analyses (Bayesian and Maximum Likelihood) of ITS and, where available, tef1-alpha clarified poorly known species and revealed new synonymies. Six species are described as new: C. cingulatus, C. dennisianus, C. djondjon, C. fuscodiscus, C. peglerianus, and C. subannulatus; two taxa (C. luteidiscus and C. singerianus) are proposed as nomina provvisoria. Twenty-seven new combinations are proposed, and several historical taxa are synonymized. Only four species occur across both the American and the African/Asian tropics, indicating that climate-selective distribution and regional isolation are drivers of speciation. Ethnomycological notes on the Haitian culinary dish of djon-djon are provided, and a dichotomous key to tropical American and African species is included, refining taxonomy and revealing previously overlooked diversity.

Metabarcoding is a powerful tool for biodiversity comparisons, where standard-size DNA barcodes (> 500 bases) offer better taxonomic resolution than shorter ones. Still, the choice of sequencing platforms and bioinformatics pipelines may strongly affect inferred diversity due to various technical biases. We assessed the relative performance of Illumina MiSeq i100 (2 × 500 paired-end), PacBio Revio and Oxford Nanopore MinION sequencing and bioinformatics pipelines, using full-length ITS amplicon sequencing datasets from a 103-species mock community and 45 composite soil samples. Despite numerous low-quality reads, PacBio yielded the lowest overall error rate and highest number of taxa. Illumina revealed the highest proportion of chimeric and index-switched reads, along with a strong bias towards shorter amplicons. MinION data analysed using PRONAME and Minovar-a bioinformatics pipeline presented here-had the largest proportion of low-quality data, and rare taxa were lost during data filtering and read polishing steps. Although Minovar enabled amplicon sequence variant (ASV) level precision for common taxa, we recommend clustering ASVs into OTUs. For PacBio, standard filtering approaches outperformed the ASV approach because they retained rare taxa. For Illumina, a stringent ASV approach or removal of rare OTUs would limit artefacts. Across all platforms, excess PCR cycles promoted chimeric and low-quality reads and lost quantitativity in biodiversity assessments. With moderate differences in effect sizes, all analytical approaches supported the conclusion that sampling design determines how we see soil biodiversity responses to land use. For biodiversity surveys based on the full-length ITS metabarcoding, we recommend using PacBio sequencing with standard, non-ASV pipelines.

In this study, we describe two new species of Cortinarius subgen. Telamonia sect. Firmiores: Cortinarius curiosus and C. ferrugineochraceus. Both species are well supported by phylogenetic analyses and are characterized by distinct morphological features. Cortinarius curiosus is resolved within the broader /Alboviolacei clade, forming a strongly supported lineage together with the three European taxa and C. obliquus from USA. Morphologically, C. curiosus can be distinguished from the European C. acutispissipes, C. alboviolaceus, and C. paralbocyaneus by first its silvery-whitish pileus and the strongly ornamented spores. Moreover, differentiation of all these four species of the clade based on spore size and ornamentation has been established as far as possible. In Europe, C. curiosus is associated with evergreen oaks, in the USA with Quercus nigra, which can be called partially evergreen. In addition, these four species are compared with the North American Cortinarius obliquus. The second new species, Cortinarius ferrugineochraceus, is placed within the /Turgidoides clade, where it forms a distinct lineage closely related to, but clearly separable from, C. turgidoides. These two taxa are compared in detail with respect to morphology, molecular characters, and ecological preferences. Cortinarius ferrugineochraceus can easily be recognized by its white, frosty veil covering pileus and the ochraceous orange to ferrugineous colors when young. In contrast, the veil of C. turgidoides is clearly fibrillose and more distinct and the pileus is more leather-brown to ferrugineous colored. Furthermore, the taxonomic status and previously proposed synonyms of C. turgidoides are critically reassessed in light of the phylogenetic evidence presented here.

We report the finding of the recent species Phellodon castaneoleucus growing in late autumn in two sites in the forest of Monte Rocca Romana, inside the Bracciano-Martignano Regional Natural Park in the province of Viterbo, Latium, Italy. Molecular analyses have been performed to obtain reliable taxonomic information. DNA-checked data is necessary to refine the distribution and ecology of the Phellodon genus which are usually only known from the few localities where they were originally collected. We have already reported interesting mycological findings (Hydnum ibericum, Hydnum ovoidesporum, Entoloma dislocatum, Ramariopsis pulchella) from this area, characterised by a forest composed in prevalence of Castanea sativa mixed with some Fagus sylvatica trees, indicating a large interesting fungal biodiversity. The annual presence of these stipitate hydnoid fungi is an indicator of the good quality of this forest habitat.

In the area of the Italian town Trevignano Romano, within the Bracciano-Martignano Regional Natural Park, we have found several rare Leucocoprinus specimens belonging to section Piloselli. In the same cypress alley in precedence, we have reported the presence of the two uncommon species Myriostoma coliforme and a still undefined Battarrea sp. Specifically, in the winter period of recent years, we have found Leucocoprinus pseudopilatianus, Leucocoprinus gaillardii, Leucocoprinus marginatus and particularly, Leucocoprinus idae-fragum. The taxonomic identities of the specimens were confirmed through molecular and phylogenetic analyses. Because information on the extremely rare L. idae-fragum is still limited, a description of these specimens is presented including their peculiar growth environment which seems now under threat of human intervention.

Voitk A. & Saar I. (2024) Three sphagnicolous species of Arrhenia: one old, one new, one recombined. - Sydowia 77: 271-290. A cystidiate sphagnicolous Arrhenia, collected in Labrador, led to review of the protologue of Agaricus umbratilis, which described Ag. umbratilis as a black omphalinoid species from wetlands of barrens, characteristic sites for Sphagnum. This species concept matched the black sphagnicolous Arrhenia telmatiaea and its synonym, Arrhenia fusconigra, with no other known lookalikes. These names were synonymized, giving the earliest and sanctioned name, Ag. umbratilis, priority. Two cystidiate collections of Ag. umbratilis, phylogenetically indistinguishable from the acystidiate populations, were discovered; the cystidiate population was described as a new forma of the species, Arrhenia umbratilis f. cystidiata. The original cystidiate sphagnicolous species of Arrhenia that triggered the review of Ag. umbratilis was a distinct species not matching any other species of Arrhenia, and was described as a new species, Arr. burzynskii. Another sphagnicolous omphalinoid, found on the same collecting trips, matched Peck's type for Agaricus montanus, and was recombined as Arrhenia montana.

Pluteus leoninus is a commonly reported species, characterized by a yellow pileus, yellow colors on the stipe, pleurocystidia provided with digitiform excrescences, and a pileipellis composed of long, fusiform elements. Several species related to P. leoninus have been described from the temperate and boreal areas of the Northern Hemisphere, and previous phylogenetic studies have shown that more than one species can be recognized around P. leoninus, but it was unclear how many, or which names, would be correct for them. We studied 141 holarctic collections in the /leoninus clade and available type collections of species in this group. Taking into account the morphological, molecular (ITS, tef1), ecological, and geographic variation in our data set, we recognize 12 holarctic species, six in Eurasia (P. favrei, P. leoninus, P. roseipes, P. ochraceoleoninus, sp. nov. P. ussuriensis, sp. nov. P. variabilicolor) and six in North America (P. aureus, sp. nov. P. croceus, sp. nov. P. flavofuligineus, P. hesperius, sp. nov. P. insularis, sp. nov. P. pumae, sp. nov.). Tropical species included by Singer in stirps Leoninus are briefly discussed: P. chrysaegis, originally described from Srik Lanka, is confirmed to occur in North America (Florida, Puerto Rico); we provide the first modern description and molecular data for P. conizatus, originally described from Sri Lanka, which is confirmed to be part of Pluteus sect. Hispidoderma but does not belong in the /leoninus clade.

Six new species of Tricholoma (Fr.) Staude in sections Genuina ( Tricholoma amarissimum, Tricholoma lutescentifolium, Tricholoma pudorinum, Tricholoma sapineum) and Fucata ( Tricholoma griseobrunneum, Tricholoma pallidogriseum) are formally described from North America east of the Rocky Mountains based on their nrITS sequence, morphology, ecology, and distribution patterns. Those species are found in summer or fall in deciduous or coniferous forests. Descriptions of their morphological characters are provided, along with photographs of the basidiomata and their micromorphology. The new species are compared with similar species occurring in North America and Europe. Tricholoma felschii Ovrebo, Hughes & Halling, in section Fucata, is here considered to represent three species, T. felschii s. str., Tricholoma subumbrinum A.H. Sm., and the newly described T. griseobrunneum. Emended descriptions of the first two species are provided to accommodate the new concepts.

Two new species of Cystodermella, C. canadensis and C. rubrogranulosa, are described based on phylogenetic and morphological grounds, and compared with similar species. Four holotypes were barcoded: Agaricus terryi, Cystoderma texense, Lepiota sipariana and Melanoleuca vinosa. Two new combinations are proposed: Melanoleuca vinosa as Ripartitella vinosa, and Cystodermella contusifolia as Cystolepiota contusifolia. Cystodermella cristallifera and C. sipariana are found to be conspecific; the older name, C. sipariana, should be adopted and C. cristallifera deprecated as a later synonym. The holotypes of three species: Agaricus terryi, Cystoderma texense and Cystodermella mazahuanensis all represent Cystodermella cinnabarina, for which a neotype is selected.

Phylogenetic study of Arrhenia peltigerina revealed a complex of seven divergent clades. Type specimens of Agaricus peltigerinus and Omphalina cupulatoides fell into separate clades; the latter was recombined as Arrhenia cupulatoides. Four clades were described as new species: Arr. baltica, Arr. fennoscandica, Arr. mohniensis, and Arr. talpoides; the fifth, with only a single specimen, was left formally undescribed. These cryptic species are uncommon—more so in North America than Scandinavia—and collections are often misidentified. Spore measurements separated Arr. baltica from the others by its narrower spores; average measurements help separate some species a bit better than ranges. So far, Arr. peltigerina was found only in North America, Arr. mohniensis and Arr. talpoides in both Europe and North America, and the remainder only in Europe. The host species of Peltigera was Peltigera hymenina for Arr. cupulatoides, Peltigera rufescens for Arr. baltica, and varied for the others. All but one collection came from soil over calcareous bedrock. Small sample size does not permit assigning high confidence to noted interspecific differences; these await confirmation by greater experience from future study.

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.

We report the finding of three recently described species in late autumn and winter (October to December) in the Bracciano-Martignano Regional Natural Park in Lazio (Italy). The species are Amanita calida, Lepiota elseae and Xerocomellus sarnarii. This is the first record of Lepiota elseae for Italy. The collection site, a Quercus thicket, is located on the slopes of San Bernardino del Malpasso in Trevignano Romano, between Monte Rocca Romana (Sabatini mountains) and the nearby Bracciano Lake. A description of the specimens is given, and a comparison is made with the few descriptions of the ambient available for previous records of the respective species.

Dr. Konstanze Bensch (MycoBank) informed us that the neotypification of Cystodermella cinnabarina (Albertini & Schweinitz: Fries) Harmaja (2002:45) was not published the Code compliant in Saar et al. 2024 (see paragraph F.5.4, May et al. 2019). Based on the Code (Turland et al. 2018; May et al. 2019) since 2019, typification acts (lecto-, neo- and epitypifications) should be registered in one of the repositories and the issued identifier should be cited with the typification.

Novel species of fungi described in this study include those from various countries as follows: Antarctica, Leuconeurospora bharatiensis from accumulated snow sediment sample. Argentina, Pseudocercospora quetri on leaf spots of Luma apiculata. Australia, Polychaetomyces verrucosus on submerged decaying wood in sea water, Ustilaginoidea cookiorum on Scleria levis, Xylaria guardiae as endophyte from healthy leaves of Macaranga tanarius. Belgium, Iodophanus taxi on leaf of Taxus baccata. Belize, Hygrocybe mirabilis on soil. Brazil, Gongronella irregularis from soil, Linodochium splendidum on decaying sheath of Euterpe oleracea, Nothophysalospora agapanthi (incl. Nothophysalospora gen. nov.) on flower stalks of Agapanthus praecox, Phaeosphaeria tabebuiae on leaf of Tabebuia sp., Verrucohypha endophytica (incl. Verrucohypha gen. nov.) from healthy roots of Acrocomia aculeata. Estonia, Inosperma apricum on soil under Quercus robur. Greece, Monosporascus solitarius isolated from surface-sterilised, asymptomatic roots of Microthlaspi perfoliatum. India, Diaporthe neocapsici on young seedling stems of Capsicum annuum, Fuscoporia naditirana on dead wood, Sebacina spongicarpa on soil, Torula kanvae from the gut of a Copris signatus beetle. Iran, Sarcinomyces pruni from twig and petiole tissues of Prunus persica and Prunus armeniaca, Xenodidymella quercicola from leaf spots of Quercus brantii. Italy, Agaricus aereiceps on grass, Agaricus bellui in meadows, Agaricus fabrianensis in urban grasslands, Beaucarneamyces muscorum on moss growing in forest, Xenoanthostomella quercus on leaf litter of Quercus ilex. Netherlands, Alfaria neerlandica on stem lesions of Cortaderia selloana, Neodictyosporium juncicola on culms of Juncus maritimus, Penicillium geertdesnooi from soil under Papaver rhoeas, Russula abscondita on rich calcareous soil with Quercus, Russula multiseptata on rich clay soil with Quercus, Russula purpureopallescens on soil with Populus, Sarocladium caricicola on leaves of Carex riparia. Pakistan, Circinaria shimlaensis on limestone rocks. Panama, Acrocalymma philodendri on leaf spots of Philodendron sp., Caligospora panamaensis on leaf litter, Chlamydocillium simulans associated with a Xylaria sp., Corynesporina panamaensis on leaf litter, Cylindromonium panamaense on twig litter of angiosperm, Cyphellophora panamaensis on twig litter of angiosperm, Microcera panamensis on leaf litter of fern, Pseudotricholoma pusillum in tropical montane forest dominated by Quercus spp., Striaticonidium panamaense on leaf litter, Yunnanomyces panamaensis on leaf litter. Poland, Albocremella abscondita (incl. Albocremella gen. nov.) from rhizoids of liverwort Conocephalum salebrosum. Portugal, Agaricus occidualis in meadows. South Africa, Alternaria elsarustiae on culms of unidentified Poaceae, Capronia capensis on dead twig of unidentified angiosperm, Codinaeella bulbinicola on dead leaves of Bulbine frutescens, Cytospora carpobroticola on leaf of Carpobrotus quadrifidus, Neophaeomoniella watsoniae on leaf of Watsonia sp., Neoplatysporoides aloigena on leaf of Aloe khamiesensis, Nothodactylaria comitabilis on living leaf of Itea rhamnoides, Nothopenidiella beaucarneae (incl. Nothopenidiella gen. nov.) on dead leaves of Beaucarnea stricta, Orbilia kirstenboschensis on dead flower stalks of Agapanthus praecox, Phragmocephala agapanthi on dead flower stalks of Agapanthus praecox, Podocarpigena hagahagaensis (incl. Podocarpigena gen. nov.) on leaf spots of Podocarpus falcatus, Sporisorium enterogonipteri from the gut of Gonipterus sp., Synnemapestaloides searsiae on leaf of Searsia populifolia, Xenophragmocapnias diospyri (incl. Xenophragmocapnias gen. nov.) on leaf spots of Diospyros sp., Yunnanomyces hagahagaensis on leaf spots of Sideroxylon inerme. Spain, Agaricus basicinctus in meadows, Agaricus quercetorum among leaf litter in oak forests, Coprinopsis palaciosii on degraded woody debris, Inocybe complutensis in calcareous loamy soil, Inocybe tanitiae in calcareous sandy soil, Mycena subfragosa on dead leaves of Salix atrocinerea, Pseudobaeospora cortegadensis in laurel forests, Trichoderma sedimenticola from fluvial sediments. Sweden, Inocybe badjelanndana on calcareous soil. Ukraine, Beaucarneamyces lupini on overwintered stems of Lupinus polyphyllus, Protocreopsis globulosa on thallus and apothecia of Lecania cyrtella on bark of Populus sp., Thyridium tiliae on dead twigs of Tilia sp. USA, Cladosporium louisianense, Cyphellophora americana from a bedroom vent, Extremus massachusettsianus from lyse buffer, Myxotrichum tapetae on carpet in basement, Neospissiomyces floridanus (incl. Neospissiomyces gen. nov.) on swab from hospital, Polychaetomyces marinus (incl. Polychaetomyces gen. nov.) on submerged driftwood in sea water, Steccherinum fragrans on hardwood fallen on the beach, Steinbeckomyces carnegieae (incl. Steinbeckomyces gen. nov.) on Carnegiea gigantea, Tolypocladium pennsylvanicum from air sampled in basement. Vietnam, Acidomyces ducanhii from Aglaia flowers, Acidomyces paludis from dead bark of Acacia sp., Phakopsora sageretiae on Sageretia theezans, Puccinia stixis on Stixis scandens. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Wingfield MJ, Jurjević Ž, et al. (2024). Fungal Planet description sheets: 1697-1780. Fungal Systematics and Evolution 14: 325-577. doi: 10.3114/fuse.2024.14.19.

UNITE (https://unite.ut.ee) is a web-based database and sequence management environment for molecular identification of eukaryotes. It targets the nuclear ribosomal internal transcribed spacer (ITS) region and offers nearly 10 million such sequences for reference. These are clustered into ∼2.4M species hypotheses (SHs), each assigned a unique digital object identifier (DOI) to promote unambiguous referencing across studies. UNITE users have contributed over 600 000 third-party sequence annotations, which are shared with a range of databases and other community resources. Recent improvements facilitate the detection of cross-kingdom biological associations and the integration of undescribed groups of organisms into everyday biological pursuits. Serving as a digital twin for eukaryotic biodiversity and communities worldwide, the latest release of UNITE offers improved avenues for biodiversity discovery, precise taxonomic communication and integration of biological knowledge across platforms.

Novel species of fungi described in this study include those from various countries as follows: Australia , Aschersonia mackerrasiae on whitefly, Cladosporium corticola on bark of Melaleuca quinquenervia , Penicillium nudgee from soil under Melaleuca quinquenervia , Pseudocercospora blackwoodiae on leaf spot of Persoonia falcata , and Pseudocercospora dalyelliae on leaf spot of Senna alata . Bolivia , Aspicilia lutzoniana on fully submersed siliceous schist in high-mountain streams, and Niesslia parviseta on the lower part and apothecial discs of Erioderma barbellatum onatwig. Brazil , Cyathus bonsai on decaying wood, Geastrum albofibrosum from moist soil with leaf litter, Laetiporus pratigiensis on a trunk of a living unknown hardwood tree species, and Scytalidium synnematicum on dead twigs of unidentified plant. Bulgaria , Amanita abscondita on sandy soil in a plantation of Quercus suber . Canada , Penicillium acericola on dead bark of Acer saccharum , and Penicillium corticola on dead bark of Acer saccharum . China , Colletotrichum qingyuanense on fruit lesion of Capsicum annuum . Denmark , Helminthosphaeria leptospora on corticioid Neohypochnicium cremicolor. Ecuador (Galapagos) , Phaeosphaeria scalesiae on Scalesia sp. Finland , Inocybe jacobssonii on calcareouss oils in dry forests and park habitats. France , Cortinarius rufomyrrheus on sandy soil under Pinus pinaster , and Periconia neominutissima on leaves of Poaceae . India , Coprinopsis fragilis on decaying bark of logs, Filoboletus keralensis on unidentified woody substrate, Penicillium sankaranii from soil, Physisporinus tamilnaduensis on the trunk of Azadirachta indica , and Poronia nagaraholensis on elephant dung. Iran , Neosetophoma fic on infected leaves of Ficus elastica . Israel , Cnidariophoma eilatica (incl. Cnidariophoma gen. nov.) from Stylophora pistillata . Italy , Lyophyllum obscurum on acidic soil. Namibia , Aureobasidium faidherbiae on dead leaf of Faidherbia albida , and Aureobasidium welwitschiae on dead leaves of Welwitschia mirabilis . Netherlands , Gaeumannomycella caricigena on dead culms of Carex elongata , Houtenomyces caricicola (incl. Houtenomyces gen. nov.) on culms of Carex disticha , Neodacampia ulmea (incl. Neodacampia gen. nov.) on branch of Ulmus laevis , Niesslia phragmiticola on dead standing culms of Phragmites australis , Pseudopyricularia caricicola on culms of Carex disticha , and Rhodoveronaea nieuwwulvenica on dead bamboo sticks. Norway , Arrhenia similis half-buried and moss-covered pieces of rotting wood in grass-grownpath. Pakistan , Mallocybe ahmadii on soil. Poland , Beskidomyces laricis (incl. Beskidomyces gen. nov.) from resin of Larix decidua ssp. polonica , Lapidomyces epipinicola from sooty mould community on Pinus nigra , and Leptographium granulatum from a gallery of Dendroctonus micans on Picea abies . Portugal , Geoglossum azoricum on mossy areas of laurel forest areas planted with Cryptomeria japonica , and Lunasporangiospora lusitanica from a biofilm covering a bio deteriorated limestone wall. Qatar , Alternaria halotolerans from hypersaline sea water, and Alternaria qatarensis from water sample collected from hypersaline lagoon. South Africa , Alfaria thamnochorti on culm of Thamnochortus fraternus , Knufia aloeicola on Aloe gariepensis , Muriseptatomyces restionacearum (incl. Muriseptatomyces gen. nov.) on culms of Restionaceae , Neocladosporium arctotis on nest of cases of bagworm moths( Lepidoptera, Psychidae ) on Arctotis auriculata , Neodevriesia scadoxi on leaves of Scadoxus puniceus , Paraloratospora schoenoplecti on stems of Schoenoplectus lacustris , Tulasnella epidendrea from the roots of Epidendrum × obrienianum , and Xenoidriella cinnamomi (incl. Xenoidriella gen. nov.) on leaf of Cinnamomum camphora . South Korea , Lemonniera fraxinea on decaying leaves of Fraxinus sp. frompond. Spain , Atheniella lauri on the bark of fallen trees of Laurus nobilis , Halocryptovalsa endophytica from surface-sterilised, asymptomatic roots of Salicornia patula , Inocybe amygdaliolens on soil in mixed forest, Inocybe pityusarum on calcareous soil in mixed forest, Inocybe roseobulbipes on acidic soils, Neonectria borealis from roots of Vitis berlandieri × Vitis rupestris , Sympoventuria eucalyptorum on leaves of Eucalyptus sp., and Tuber conchae fromsoil. Sweden , Inocybe bidumensis on calcareous soil. Thailand , Cordyceps sandindaengensis on Lepidoptera pupa, buried in soil, Ophiocordyceps kuchinaraiensis on Coleoptera larva, buried in soil, and Samsoniella winandae on Lepidoptera pupa, buriedinsoil. Taiwan region (China) , Neophaeosphaeria livistonae on dead leaf of Livistona rotundifolia . Türkiye , Melanogaster anatolicus on clay loamy soils. UK , Basingstokeomyces allii (incl. Basingstokeomyces gen. nov.) on leaves of Allium schoenoprasum . Ukraine , Xenosphaeropsis corni on recently dead stem of Cornus alba. USA , Nothotrichosporon aquaticum (incl. Nothotrichosporon gen. nov.) from water, and Periconia philadelphiana from swab of coil surface. Morphological and culture characteristics for these new taxa are supported by DNA barcodes.

We studied the taxonomy of Pluteus podospileus and similar species using morphological and molecular (nrITS, TEF1-α) data, including a detailed study of the type collections of P. inflatus var. alneus, Pluteus minutissimus f. major, and P. granulatus var. tenellus. Within the P. podospileus complex, we phylogenetically confirmed six species in Europe, five in Asia, and eight in North America. Based on our results, we recognize P. seticeps as a separate species occurring in North America, while P. podospileus is limited to Eurasia. We describe six new species and a new variety: P. absconditus, P. fuscodiscus, P. gausapatus, P. inexpectatus, P. millsii, and P. notabilis and its variety, P. notabilis var. insignis. We elevate Pluteus seticeps var. cystidiosus to species rank as Pluteus cystidiosus. Based on the holotype of P. inflatus var. alneus, collections of P. inflatus identified by Velenovský, and several modern collections, we resurrect the name P. inflatus. Based on molecular analyses of syntypes of Pluteus minutissimus f. major and a holotype of Pluteus granulatus var. tenellus, we synonymize them under P. inflatus. We also increase our knowledge about the morphology and distribution of P. cutefractus.

Nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) sequence data from eight type specimens of previously described Squamanita species were obtained. Phylogenetic analysis of ITS and partial nuc 28S rDNA data revealed Squamanita as paraphyletic splitting into two monophyletic groups, which we recognize as the genera Squamanita and Dissoderma. We accept 14 Squamanita and nine Dissoderma species, provide the first sequences of 13 of these, and describe six new species of Squamanita and three new species of Dissoderma. We transfer three species of Squamanita into Dissoderma, one into Cystoderma, and treat S. basii and S. umbilicata as synonyms of D. paradoxum. Squamanita can be distinguished from Dissoderma by the generally larger fleshier basidiomata with a tricholomatoid or amanitoid stature and yellowish to tawny brown pileus and often similarly colored stipe. Most species have cheilo- and pleurocystidia. Species of Dissoderma are small, collybioid or mycenoid, lack cystidia, and the pileus and often upper stipe are purplish gray. Both genera parasitize basidiomata of other agarics.

Mushroom-forming fungi are important sources of food and medicine in many regions of the world, and their development and health are known to depend on various microbes. Recent studies have examined the structure of mushroom-inhabiting bacterial (MIB) communities and their association with local environmental variables, but global-scale diversity and determinants of these communities remain poorly understood. Here we examined the MIB global diversity and community composition in relation to climate, soil and host factors. We found a core global mushroom microbiome, accounting for 30% of sequence reads, while comprising a few bacterial genera such as Halomonas, Serratia, Bacillus, Cutibacterium, Bradyrhizobium and Burkholderia. Our analysis further revealed an important role of host phylogeny in shaping the communities of MIB, whereas the effects of climate and soil factors remained negligible. The results suggest that the communities of MIB and free-living bacteria are structured by contrasting community assembly processes and that fungal-bacterial interactions are an important determinant of MIB community structure.

Fungal species are not immune to the threats facing animals and plants and are thus also prone to extinction. Yet, until 2015, fungi were nearly absent on the IUCN Red List. Recent efforts to identify fungal species under threat have significantly increased the number of published fungal assessments. The 597 species of fungi published in the 2022-1 IUCN Red List update (21 July 2022) are the basis for the first global review of the extinction risk of fungi and the threats they face. Nearly 50% of the assessed species are threatened, with 10% NT and 9% DD. For regions with a larger number of assessments (i.e., Europe, North America, and South America), subanalyses are provided. Data for lichenized and nonlichenized fungi are also summarized separately. Habitat loss/degradation followed by climate change, invasive species, and pollution are the primary identified threats. Bias in the data is discussed along with knowledge gaps. Suggested actions to address these gaps are provided along with a discussion of the use of assessments to facilitate on-the-ground conservation efforts. A research agenda for conservation mycology to assist in the assessment process and implementation of effective species/habitat management is presented.