Jean-Michel Bellanger

Imperator torosus is a polymorphic, critical Friesian bolete, originally described from Central Europe, but with a convoluted taxonomic history which caused much uncertainty in delimiting it from similar-looking species. Previous molecular phylogenetic analyses confidently indicated that I. torosus , as presently circumscribed, is a polyphyletic species in need of taxonomic revision. Based on a two-locus (ITS and LSU) phylogeny, pairwise distance and percent nucleotide similarity analyses, as well as morphological and ecological evidence, I. torosus s. str. is defined and Imperator occultus described as a novel species. Besides unravelling the intricate taxonomic history of I. torosus s. l., detailed macro- and micro-morphological descriptions based on well-documented collections are provided for both I. torosus s. str. and I. occultus , accompanied by colour photographs taken in their natural habitats and line drawings of their main microscopic features. A comprehensive and circumstantial discussion upon the reasons why the recent epitypification of B. torosus is deemed untenable is presented. Morphological comparisons with xanthoid phenotypes of Imperator rhodopurpureus ( I. rhodopurpureus f. xanthopurpureus and I. xanthocyaneus ), as well as their taxonomic placement within the genus Imperator are also elucidated and discussed.

A new peat-associated species of Arrhenia, A. turficola sp. nov., is described. Hitherto known from continental Europe, the species is likely widespread, but uncommon. ITS and LSU nrDNA sequences reveal that it forms a clade distant from that containing all previously known hygrophilous species. Comparisons with ecologically and morphologically similar species are also discussed. In particular, although its distinct grey colour recalls the terricolous A. griseopallida, the striate pileus is inconsistent with Desmazières’ protologue, and its morphological, ecological, and molecular features do not match any of the diverse modern interpretations of that name.

Novel species of fungi described in this study include those from various countries as follows: Argentina, Septoria reinamora on leaf spots of Mutisia spinosa. Australia, Cortinarius albofolliculus on mossy soil, Cortinarius descensoriformis among leaf litter, Cortinarius kaki among leaf litter, Cortinarius lissosporus in leaf litter, Cortinarius malogranatus in leaf litter, Cortinarius meletlac on soil in mixed forest, Cortinarius sebosioides in long decayed wood litter, Helicogermslita australiensis as an endophyte from healthy leaves of Archontophoenix cunninghamiana, Puccinia clemensiorum on culms of Eleocharis ochrostachys, Puccinia geethae on leaves of Cyperus brevifolius, Puccinia marjaniae on leaves of Nymphoides indica, Puccinia scleriae-rugosae on leaves of Scleria rugosa. Brazil, Dactylaria calliandrae on living leaf of Calliandra tweediei, Mucor cerradoensis from soil, Musicillium palmae on living leaves of unidentified palm species, Neodendryphiella agapanthi from stalks of Agapanthus praecox, Parafusicladium riodejaneiroanum on living leaves of native bamboo, Parapenidiella melastomatis on living leaves of unidentified Melastomataceae, Pararamichloridium ouropretoense on living leaves of unidentified Poaceae, Pentagonomyces endophyticus (incl. Pentagonomyces gen. nov.) as endophytic from roots of Musa acuminata, Polyschema endophytica from healthy roots of coffee plant, Purimyces endophyticus as root endophyte of Cattleya locatellii, Ramularia rhododendri on living leaves of Rhododendron sp., Staphylotrichum soli from soil, Trichoderma sexdentis from leaves inside a nest of the leaf-cutting ant Atta sexdens rubropilosa, Wiesneriomyces soli from soil. France, Cosmospora nemaniae on dead or effete stromata of Nemania cf. colliculosa, Inocybe alnobetulae in subalpine green alder stands, Stylonectria hygrophila on dead twigs of Betula pubescens. Germany, Coniochaeta corticalis from bark humus, Coniochaeta fermentaria from fermentation residues from biogas plants, Coniochaeta fibricola from softwood fibres, Coniochaeta weberae from bark humus, Inocybe canicularis on calcareous to more acidic soil with conifers. Iceland, Inocybe islandica associated with Dryas octopetala. India, Vishniacozyma indica on dead twigs. Iran, Botryotrichum lycii on rotten leaf of Lycium depressum. Italy, Cuphophyllus dolomiticus among Salix retusa, Salix reticulata and Dryas octopetala, Inocybe subentolomospora on moss with the presence of Alnus incana, Populus nigra and Salix spp. Malaysia, Catenulostroma pellitae on leaf spots of Eucalyptus pellita. Mexico, Colletotrichum mexicanus from fruit of Persea americana cv. Hass. New Caledonia (France), Cortinarius caeloculus, Cortinarius luteigemellus and Cortinarius perpensus on soil under Nothofagus aequilateralis. New Zealand, Cytospora braithwaitei on branch of Malus domestica. Pakistan, Callistosporium khalidii on humus soil, Entoloma lilacinum on litter in conifer forest, Laccaria decolorans on litter in broad-leaved subtropical forest. Poland, Pseudoneoconiothyrium modrzynanum from resin of Larix decidua ssp. polonica, Tuberculiforma enigmatica isolated from sooty mould community on Quercus robur leaves. Portugal, Clavulus hemisphaericus (incl. Clavulus gen. nov.) on mossy slopes and under Laurus leaf litter, Entoloma daegae on sandy, granitic soil, Hygrocybe aurantiocitrina under laurel forest, Hygrocybe sanguineolutea gregarious in laurel forest, Hygrocybe vulcanica on mossy areas of laurel forest areas, Pachyphlodes algarvensis on sandy soil under Cistus salvifolius, Quercus suber and Pinus pinea. South Africa, Amycosphaerella podalyriae on leaf of Podalyria calyptrata, Erythrobasidium eucalypti from the gut of Gonipterus sp., Letendraea goniomae on leaves of Gonioma kamassi, Pezicula brabeji and Sphaerulina brabeji on twigs of Brabejum stellatifolium, Stachybotrys conicosiae on dead flower head of Conicosia elongata, Talaromyces ignescens from soil. Spain, Cortinarius phaeobrunneus on soil under Quercus ilex and Q. faginea, Inocybe pini-halepensis among grass and fallen leaves of Pinus halepensis, Inocybe subporcorum in sandy soils under Quercus ilex subsp. ballota and Pinus pinaster, Mycena morenoi on dead leaves of Betula pubescens and Salix atrocinerea, Pachyphlodes iberica on clayey and loamy soil under Quercus ilex and Quercus rotundifolia, Ramariopsis coronata in laurel forest. Switzerland, Inocybe minata in a bog on very wet acidic soil with Salix spp. and Betula spp. Thailand, Hypocrella khonsanitii on scale insects (Coccidae), Petchiella hymenopterorum on hymenopteran pupae in the nest (Hymenoptera). Trinidad and Tobago, Neodevriesia maravalensis from office swab. Türkiye, Russula anatolica under Quercus vulcanica. UK, Paracylindrosporium dactylorhizae (incl. Paracylindrosporium gen. nov.) on leaf spots of Dactylorhiza sp., Niesslia hepworthiae and Niesslia libertiae on living leaves of Libertia grandiflora. Ukraine, Lichenohendersonia cetrariae on thallus of terricolous Cetraria aculeata. USA, Atromagnispora indianensis (incl. Atromagnispora gen. nov.) on submerged wood in a freshwater stream, Cytospora michiganensis from utility room (settle plate), Exophiala aeris from air (settle plate), Hongoboletus americanus from mixed pine-hardwood forest, Lorrainsmithia pennsylvanica from bedroom, air, Superstratomyces massachusettsanus from lyse buffer. Vietnam, Aspergillus halopiscium on dry marine anchovy Stolephorus commersonnii. Morphological and culture characteristics are supported by DNA barcodes.

Numerous collections made in deciduous and evergreen oak woodlands of Europe allowed us to re-evaluate, both morphologically and molecularly, the systematic position and taxonomic boundaries of Cortinarius chevassutii f. personatus. This infraspecific taxon and Cortinarius chevassutii share the same ecological niche, an identical distribution pattern, and can even co-occur in the same spot, making their distinction quite challenging, morphologically. However, the phylogenetic analysis of our broad dataset supports two reproductively isolated taxa that both deserve the rank of species. According to recent findings, Cortinarius pseudobulliardioides is the name to apply to the former C. chevassutii f. personatus. Based on present knowledge, spore size and average length/width ratio represents the most reliable diagnostic criterion to separate the two species. Additionally, through next generation sequencing (Illumina) of its holotype, we here reveal the phylogenetic position of Cortinarius variebulbus within the same sect. Crassispori. Recent phylogenetically confirmed collections of this species allow us to document and illustrate this taxon for the first time.

Thirty-one alpine species of Cortinarius (Agaricales, Cortinariaceae) were described from the alpine zone of the Alps during the second half of the XX century, by the Swiss mycologist Jules Favre, and by the French mycologists Denise Lamoure and Marcel Bon. Notoriously difficult to identify by macro- and microscopical characters, most of these species, which belong to subgen. Telamonia, have been thoroughly revised in global publications based on type sequencing. Recent surveys in the alpine areas of France (Savoie) and Italy (Lombardy), as well as the sequencing of D. Lamoure’s collections, identified three new species that are here described and illustrated: C. dryadophilus in sect. Castanei, C. infidus in sect. Verni, and C. saniosopygmaeus in sect. Saniosi. The holotypes of C. caesionigrellus Lamoure and C. paleifer var. brachyspermus Lamoure could be sequenced. A recent collection of the former is described and illustrated here for the first time, and based on available data, the latter name is recombined as Cortinarius flexipes var. brachyspermus comb. nov. Lastly, C. argenteolilacinus var. dovrensis is reported from the alpine zone for the first time and a new combination, Thaxterogaster dovrensis comb. & stat. nov. is introduced in the present work.

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.

The UHPLC–HRMS analysis of Cortinarius ominosus basidiomata extract revealed that this mushroom accumulated elevated yields of an unreported specialized metabolite. The molecular formula of this unknown compound, C₁₇H₁₀O₈, indicated that a challenging structure elucidation lay ahead, owing to its critically low H/C atom ratio. The structure of this new isolate, namely ominoxanthone (1), could not be solved from the interpretation of the usual set of 1D/2D NMR data that conveyed too limited information to afford a single, unambiguous structure. To remedy this, a Computer-Assisted Structure Elucidation (CASE) workflow was used to rank the different possible structure candidates consistent with our scarce spectroscopic data. DFT-based chemical shift calculations on a limited set of top-ranked structures further ascertained the determined structure for ominoxanthone. Although the determined scaffold of ominoxanthone is unprecedented as a natural product, a plausible biosynthetic scenario involving a precursor known from cortinariaceous sources and classical biogenetic reactions could be proposed.

The authors describe a bovinoid Cortinarius species new to science, C. insanus sp. nov., sister to the poorly known and phylogenetically isolated C. furiosus, emended here. Section Furiosi sect. nov. is also introduced to accommodate the two taxa and distinguish them from other bovinoid lineages.