Two new Cortinarius species in subgenus Leprocybe from Southwest China.

Two new Cortinarius species in subgenus Leprocybe, Cortinarius hengduanensis and C. yadingensis, are proposed based on a combination of morphological and molecular evidence. Cortinarius hengduanensis has distinct olive tinged basidiomata, a squamulose pileus, and small, subglobose to broadly ellipsoid basidiospores, the ITS sequence differs from that of C. flavifolium by at least 28 substitutions and independent positions. Cortinarius yadingensis has a squamulose pileus and subglobose to broadly ellipsoid coarsely verrucose basidiospores, the ITS sequence has at least 11 substitutions and index position deviations from the other members of the Leprocybe section. Both new species were found in mixed forests of southwest China.

Purple haze: Cryptic purple sequestrate Cortinarius in New Zealand.

CORTINARIUS: is a species-rich ectomycorrhizal genus containing taxa that exhibit agaricoid or sequestrate basidiome morphologies. In New Zealand, one of the most recognizable and common Cortinarius species is the purple sequestrate fungus, C. porphyroideus. We used genome skimming of the almost 100-y-old type specimen from C. porphyroideus to obtain the nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) and partial nuc rDNA 28S (28S) sequences. The phylogenetic position of C. porphyroideus was established, and we found that it represents a rarely collected species. Purple sequestrate Cortinarius comprise multiple cryptic species in several lineages. We describe four new species of Cortinarius with strong morphological similarity to C. porphyroideus: Cortinarius diaphorus, C. minorisporus, C. purpureocapitatus, and C. violaceocystidiatus. Based on molecular evidence, Thaxterogaster viola is recognized as Cortinarius violaceovolvatus var. viola. These species are associated with Nothofagus (southern beech) and have very similar morphology to C. porphyroideus but are all phylogenetically distinct based on molecular data.

Unveiling new sequestrate Cortinarius species from northern Patagonian Nothofagaceae forests based on molecular and morphological data.

Because of systematic sampling campaigns in the northern Patagonian Nothofagaceae forests of Argentina, several specimens of sequestrate fungi were collected. Some of those collections showed phylogenetic affinities and morphological similarities to members of the formerly recognized sequestrate genus Thaxterogaster, currently a synonym of Cortinarius on the basis of molecular data. Comparisons of macro- and micromorphological features and sequences of nuc rDNA internal transcribed spacer (ITS) regions have revealed that these collections belong to formerly undescribed species. The sequences of the four new taxa presented here, Cortinarius flavopurpureus, C. translucidus, C. nahuelhuapensis, and C. infrequens, were combined into a data set including additional sequences generated from herbarium collections and retrieved from public gene databases and analyzed by maximum likelihood and Bayesian inference methods. The four new species were resolved as distinct clades with strong support; at the same time, they showed unique morphological characteristics (hypogeous to subhypogeous habit, complete gasteromycetation, and spore shape and ornamentation) that separate them from previously described Cortinarius species. In addition, several undescribed and/or not previously sequenced species from these forests were detected through phylogenetic analysis of ectomycorrhizal root tip sequences. A key of characters to identify the sequestrate Cortinarius from Patagonia is provided.

New species of Cortinarius sect. Austroamericani, sect. nov., from South American Nothofagaceae forests.

In this study, we document and describe the new Cortinarius section Austroamericani. Our results reveal high species diversity within this clade, with a total of 12 recognized species. Of these, only C. rufus was previously documented. Seven species are described as new based on basidiomata collections. The four remaining species are only known from environmental sequences. All examined species form ectomycorrhizal associations with species of Nothofagaceae and are currently only known from Argentinean and Chilean Patagonia. The phylogenetic analysis based on the nuc rDNA internal transcriber spacer (ITS1-5.8S-ITS2 = ITS) and partial 28S gene (28S) sequences shows that this section is related to other taxa from the Southern Hemisphere. Species in this group do not belong to subg. Telamonia, where C. rufus was initially placed. Cortinarius rufus and the newly described C. subrufus form a basal clade within sect. Austroamericani that has a weakly supported relationship with the core clade. Because the two species are morphologically similar to species from the core clade and share their distribution and Nothofagaceae associations, we include them here as part of sect. Austroamericani sensu lato (s.l.) until more material is available to refine the delimitation.

The enigmatic Cortinarius magellanicus complex occurring in Nothofagaceae forests of the Southern Hemisphere.

Cortinarius magellanicus Speg. is an edible, ectomycorrhizal fungus, widely distributed in Argentina, Chile and New Zealand. However, earlier studies already indicated that the epithet 'magellanicus' might have been applied in a wide sense, thus circumscribing several species. A neotype was designated by Moser and Horak (1975) due Spegazzini's type was lost. Argentinian Nothofagaceae forests' samples, from autumn of 2017, morphologically recognized as C. magellanicus were used for a phylogenetic analysis, including sequences from type material and closely related species. Our results showed that C. magellanicus represents a complex of species, with at least three phylogenetic lineages, each with strong regionalism and distinct host associations. Cortinarius magellanicus s. str. is restricted to Patagonia of Argentina and Chile. The misidentified reports from New Zealand and Australia represent distinct and different lineages. In the present contribution, the re-description of C. magellanicus is based on neotype material and two new species are proposed. Cortinarius vitreopileatus var. similissimus is described as variety from New Zealand resembling C. magellanicus, however without close phylogenetic relationship to it. The taxonomic delimitation for C. magellanicus species complex is of high relevance due to the abundance of these fungi and their ectomycorrhizal role in Nothofagaceae forests in Gondwanian region.

A systematic overview of Descolea (Agaricales) in the Nothofagaceae forests of Patagonia.

The descolea clade includes species of ectomycorrhizal basidiomycetes in the genera Descolea, Setchelliogaster, Descomyces, and Timgrovea that are known primarily from the Southern Hemisphere. Taxa in this group produce basidiomes that range in morphology from typical epigeous mushrooms (Descolea) and secotioid taxa (Setchelliogaster) to fully gasteroid species (Descomyces and Timgrovea). High intraspecific morphological variation has been reported in several species within this clade, suggesting that careful morphological and molecular studies are needed to refine species concepts. Molecular analyses of fresh Patagonian collections in conjunction with taxonomic studies have confirmed high variability in key morphological features, including overall sporocarp form, spore shape and dimensions, universal veil remnants, and cuticle configuration. Based on our synthesis, we emend the genus Descolea to include sequestrate species. We describe the new sequestrate taxon Descolea inferna sp. nov. from Nothofagaceae forests in Patagonia and we propose Cortinarius squamatus as a synonym of our new combination Descolea brunnea. We also formalize the identity of Descolea pallida as a synonym of Descolea antarctica and provide new specimens of Cortinarius archeuretus, a species that has not been encountered since the original discovery during the expeditions of Roland Thaxter in 1905-1906. Here we re-describe and transfer this species to Descolea as D. archeureta. We also discuss diagnostic features that can be used to delimitate the four known South American taxa in the descolea clade.

Spring and early summer species of Cortinarius, subgenus Telamonia, section Colymbadini and /Flavobasilis, in the mountains of western North America.

Seven species of Cortinarius, subgenus Telamonia, section Colymbadini and /Flavobasilis, are reported from conifer forests in the mountains of western North America. They typically produce basidiomes in the spring and summer. Only one species, C. colymbadinus, is widespread, occurring in Europe and western North America, but to date not reported from California. Cortinarius bridgei, C. flavobasilis, C. rumoribrunsi, C. vernalishastensis, and C. vernalisierraensis are new species. The first two are found throughout the western mountains, whereas the latter three thus far are known only from California. Cortinarius ahsii, a common species in the Rocky Mountains and Pacific Northwest, also has not been recorded from California.

Arbutoid mycorrhizas of the genus Cortinarius from Costa Rica.

Arbutoid mycorrhizas of Comarostaphylis arbutoides (Arbutoidea, Ericaceae) from neotropical montane forests are rarely described. To date, only mycorrhizal associations with the fungal species Leccinum monticola, Leotia lubrica and Sebacina sp. are known from literature. The genus Cortinarius is one of the most species-rich ectomycorrhizal taxa with over 2000 assumed species. In this study, two sites in the Cordillera de Talamanca of Costa Rica were sampled, where Com. arbutoides is endemic and grows together with Quercus costaricensis. Using a combined method of rDNA sequence analysis and morphotyping, 33 sampled mycorrhizal systems of Cortinarius were assigned to the subgenera Dermocybe, Phlegmacium and Telamonia. Specific plant primers were used to identify the host plant. Here, we present the phylogenetic data of all found Cortinarii and describe four of the arbutoid mycorrhizal systems morphologically and anatomically.

Determining threshold values for barcoding fungi: lessons from Cortinarius (Basidiomycota), a highly diverse and widespread ectomycorrhizal genus.

Different distance-based threshold selection approaches were used to assess and compare use of the internal transcribed spacer (ITS) region to distinguish among 901 Cortinarius species represented by >3000 collections. Sources of error associated with genetic markers and selection approaches were explored and evaluated using MOTUs from genus and lineage based-alignments. Our study indicates that 1%-2% more species can be distinguished by using the full-length ITS barcode as compared to either the ITS1 or ITS2 regions alone. Optimal threshold values for different picking approaches and genetic marker lengths inferred from a subset of species containing major lineages ranged from 97.0% to 99.5% sequence similarity using clustering optimization and UNITE SH, and from 1% to 2% sequence dissimilarity with CROP. Errors for the optimal cutoff ranged from 0% to 70%, and these can be reduced to a maximum of 22% when excluding species lacking a barcode gap. A threshold value of 99% is suitable for distinguishing species in the majority of lineages in the genus using the entire ITS region but only 90% of the species could be identified using just the ITS1 or ITS2 region. Prior identification of species, lacking barcode gaps and their subsequent separate analyses, maximized the accuracy of threshold approaches.

Long-distance dispersal and speciation of Australasian and American species of Cortinarius sect. Cortinarius.

We present a multigene phylogeny (partial nuc rDNA and RPB2) of Cortinarius sect. Cortinarius (i.e. the C. violaceus group), which reveals eight species distributed in Europe, Australasia, South America, Central America and North America. Relaxed molecular clock analyses suggested that diversification began during the Miocene, thus rejecting more ancient Gondwanan origin scenarios among the taxa currently occurring in the northern and southern hemispheres. There was strong support for an Australasian origin of the C. violaceus group with initial dispersal to the Neotropics, followed by migration into North America and Europe. A dispersal-extinction cladogenesis model that includes a parameter for founder effects was the most highly supported biogeographic model in the program BioGeoBEARS. A maximum likelihood analysis showed the most recent common ancestor of sect. Cortinarius was an angiosperm ectomycorrhizal associate. Ancestral associations at the plant family level, however, were ambiguous. Of eight recovered species-level lineages, C. violaceus is the only one that associates with Pinaceae and the only species to associate with both Pinaceae and angiosperms. This analysis showed that long-distance dispersal and founder event speciation have been important factors during evolution of the C. violaceus group.

Some new and interesting taxa of Cortinarius subgenus Phlegmacium from the European Mediterranean Basin.

We clarify the taxonomy and nomenclature of several taxa of the genus Cortinarius subgenus Phlegmacium. To this aim, we have used a combination of morphological and molecular data. The evolutionary relationships of the species were inferred by comparison of the nuITS by means of weighted maximum parsimony, maximum likelihood and two different types of Bayesian methods (with and without a priori alignments). Phylogenetic resolution and support of all or most of the species included in this study and their relationships were possible only when including the phylogenetic signal from ambiguously aligned regions in weighted maximum parsimony analyses (recoded INAASE characters) and when the analysis simultaneously optimized alignment and phylogeny (with BAli-phy). Three species are described as new, Cortinarius mediterraneensis, C. cistoglaucopus and C. palazonianus, and C. olivaecodionysae is proposed for C. dionysae f. olivaceus. Descriptions are provided for these taxonomic and nomenclatural novelties, along with discussions of morphological and phylogenetic affinities to closely related taxa. Scanning microphotographs of the basidiospores are provided for the discussed taxa, and color pictures of the basidiomes in their natural habitat are provided for C. cistoglaucopus, C. mediterraneensis and C. palazonianus.

Concordance of seven gene genealogies compared to phenotypic data reveals multiple cryptic species in Australian dermocyboid Cortinarius (Agaricales).

This study aims to delimit species of Australian dermocyboid fungi (Cortinarius, Agaricales) using genealogical concordance on well-characterised phenotypic species and to assess the utility of seven loci for DNA barcoding Australian Cortinarius taxa. Eighty-six collections of dermocyboid Cortinarius were sampled from across southern Australia. Phenotypic species were first recognised by performing clustering analyses on a comprehensive phenotypic dataset including morphological, colour and pigment data. Then phylogenetic species were delimited from the concordance of seven locus genealogies (ITS, nLSU, gpd, mcm7, rpb1, rpb2 and tef1). Seventeen phenotypic species were recognised while the concordance of gene genealogies recovered 35 phylogenetic species. All loci except for LSU recovered most phylogenetic species, although only rpb1 correctly identified all phylogenetic species. The ITS region is confirmed as an effective barcode for Cortinarius and a standard pairwise distance threshold of 2.0% is proposed to DNA barcode Australian Cortinarius taxa. Australian dermocyboid fungi belong in separate clades to the boreal clade Dermocybe, mostly in the clade Splendidi. This study provides a solid foundation for future ecological, taxonomic and systematic research on one of the most diverse genera of mushrooms worldwide.

The species of Cortinarius, section Bovini, associated with conifers in northern Europe.

Cortinarius bovinus and morphologically similar conifer-associated species were studied using material mainly from northern Europe. To stabilize the nomenclature, relevant types were examined. Phylogenetic relationships and species limits were investigated with rDNA ITS and nuclear rpb2 sequences as well as morphological data. We recognize seven species: C. bovinus (neotypified) and six new species, C. anisochrous, C. bovinaster, C. bovinatus, C. fuscobovinus, C. fuscobovinaster and C. oulankaënsis. Their taxonomy, ecology, distribution and relationships are discussed, and a key to species is provided. Based on our phylogeny and morphological data the species were placed in section Bovini.

Cortinarius section Sanguinei in North America.

The North American species of Cortinarius section Sanguinei were studied using morphological characters and ITS and RPB2 sequence data. Several type collections also were examined. Four species were identified: C. harrisonii sp. nov, C. neosanguineus sp. nov., C. sanguineus and C. sierraensis comb. nov. Of these, C. sanguineus also occurs in Europe together with C. puniceus, a fifth member of the section. Typical features of these species include ± red, fairly small basidiomata, stipe basal mycelium often with yellow to reddish yellow tints, amygdaloid to ellipsoid spores, and aniline-red lamellar trama and pileipellis hyphae when mounted in KOH. Two other species with red lamellae C. marylandensis comb. nov. and C. smithii stat. nov. & nom. nov. also are discussed.

A new Cortinarius of section Calochroi (Basidiomycota, Agaricomycetes) from Mediterranean Quercus woodlands (Italy).

A new species of Cortinarius, C. flavoaurantians sp. nov., is described from Italian Quercus woods based on both morphological and ITS rDNA data. This taxon is characterized by a yellowish pileus and cortina, a white universal veil and a pileipellis that reacts yellow-orange with KOH. Illustrations of the key micromorphological features and fresh basidiomata in situ are provided. Closely related species are discussed.

Cortinarius sanguineus and equally red species in Europe with an emphasis on northern European material.

The red species of Cortinarius subgenus Dermocybe in Europe were studied based on morphological and molecular data. Three completely red species were recognized: C. sanguineus (syn. C. sanguineus var. aurantiovaginatus), C. puniceus (syn. C. cruentus, C. rubrosanguineus) and C. vitiosus comb. nov. Cortinarius sanguineus has dusky red to red pileus, reddish yellow mycelium and lacking or with only slightly encrusted hyphae in pileipellis. It occurs in mesic to damp forests with Picea, often on rich soil in the boreal and montane areas of Europe, presumably also in eastern Canada. Cortinarius puniceus differs from C. sanguineus by its stronger purplish red, narrower spores and spot-like encrusted hyphae in pileipellis. It grows with deciduous trees in the temperate zone of Europe. Cortinarius vitiosus is known only from Fennoscandia and occurs in dry to mesic coniferous forests. It has fairly thin, often zonate, dark red to dark reddish brown pileus, pale red mycelium, small spores and encrusted lamellar trama and pileipellis hyphae. In addition to these three species C. fervidus and C. phoeniceus occasionally have red basidiomes. The relationships of the species were inferred by analysis of ITS sequences. Our study suggests that the section Sanguinei, as earlier defined, is polyphyletic. Here the section is limited to include C. sanguineus, C. puniceus and North American D. sierraensis. The relationships with other red species were not determined. Section Dermocybe, including C. cinnamomeus, C. croceus and C. uliginosus, formed a monophyletic group, and the section Malicoriae had some support. A total of 34 new sequences are published including nine from type specimens.

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.

Cortinarius sect. Armillati in northern Europe.

Cortinarius sect. Armillati (subgenus Telamonia) was studied extensively based on morphology and molecular data. A total of about 1000 specimens, mostly from Fennoscandia, were revised. The nomenclature of the species was confirmed by sequencing the type material. Phylogenetic relationships were inferred by analyses of ITS, and the results were compared with the morphological and ecological data. Based on macro- and micromorphological characters, as well as molecular data, section Armillati contains only the medium to large species with slightly hygrophanous pileus and ± reddish or in some species yellowish brown to rose brown universal veils. The other red-brown-veiled species, previously included in Armillati, seem to belong to at least seven different sections or clades: sect. Anthracini, sect. Boulderenses, sect. Brunneotincti p.p., sect. Cinnabarini, sect. Fulvescentes, /Fuscoperonatus, and /Praestigiosus. Our study recognized six Armillati species from northern Europe: C. armillatus, C. luteo-ornatus, C. paragaudis, and three species described as new, C. pinigaudis, C. roseoarmillatus, and C. suboenochelis. The former three also occur in North America. Two additional species, C. subarmillatus (Japan) and C. quercoarmillatus (Costa Rica), are known outside the area. Based on the phylogenetic analysis, the species associated with deciduous trees, C. armillatus, C. quercoarmillatus, and C. roseoarmillatus, all with dextrinoid, thick-walled spores, formed a separate group from the mainly conifer-associated species, C. luteo-ornatus, C. paragaudis, C. pinigaudis and C. suboenochelis, all with fairly thin to moderately thick-walled, indextrinoid to moderately dextrinoid spores. Descriptions of the northern European species are provided, the distribution is mapped and their taxonomy, ecology, distribution, and relationships are discussed. A total of 64 new sequences of 12 species are reported including 17 sequences from type material. Our study also suggests that ITS sequences are not always sufficiently variable for species-rank recognition (barcoding) in Cortinarius.