Ibai Olariaga

The Dilemma of Species Recognition in the Field When Sequence Data are not in Phase with Phenotypic Variability

Abstract This contribution on the genus Cantharellus in North America introduces three new look-alikes of already known species in the eastern United States and thereby exposes the problem of species delimitation in Cantharellus. The small, reddish pink to orange C. corallinus sp. nov. is yet another look-alike of C. cinnabarinus, while the new C. flavolateritius is proposed as a new southern relative of C. lateritius. Both new species are, however, genetically clearly divergent. Such a scenario of “cryptic species” corresponds to a concept that is widely admitted even by field mycologists and therefore easily accepted. In contrast, typical forms of the here newly described C. velutinus sp. nov. are nearly indistinguishable from C. lateritius, but the phenotypic variability of this new species (as supported by phylogenetic inference of the TEF-1 gene) is so impressive that it is hard to accept that the various observed phenotypic forms all belong to a single species as indeed suggested by their identical sequence data. The latter scenario, that of lumping easily separable phenotypic forms in the field under a single species epitheton encounters much more criticism from most field mycologists and is only reluctantly accepted.

Setting the Record Straight on North American Cantharellus

Abstract The authors assembled for the first time a sequence dataset representative of all 29 presently described North American Cantharellus species, including not only all six newly described North American species presented in this special issue, but very importantly, also newly obtained partial ITS and LSU sequence data from the type specimens of C. camphoratus and C. septentrionalis, two species that supposedly had never been recollected in the United States since their original description. As such, they hope to put the record straight for future research on Cantharellus in North America and to allow for a more precise identification and appreciation of newly collected, sequenced specimens.

Assessing the Taxonomic Identity of White and Orange Specimens of Cantharellus: Occasional Colour Variants or Independent Species?

Abstract Species of Cantharellus contain carotenoid pigments, which produce yellow, orange and red colours. As microscopic characters are of limited value to separate species, colour has always been an important taxonomic character for species delimitation in Cantharellus. Entirely white Cantharellus or specimens lacking yellow pigments are occasionally reported from Europe, but it is unclear whether these represent independent species or are simply unusual colour variants of otherwise yellow species. The main objective of this study is to assess the taxonomic identity of such white and orange specimens using molecular data. In the context of an ongoing 4-gene phylogeny of European Cantharellus, an ITS2-LSU dataset representing all the European taxa was assembled, including 9 white and 3 orange specimens. Bayesian analyses revealed that white specimens may occasionally occur in C. amethysteus, C. cibarius, C. ferruginascens, C. pallens and C. romagnesianus, whereas orange specimens are found in C. cibarius and C. pallens. We therefore associate white specimens with an albinism phenomenon due to a possible absence of carotenoids. Accordingly, the names C. cibarius var. inodorus and C. cibarius f. pallidus are neotypified and synonymized with C. cibarius, while C. gallaecicus is considered a synonym of C. romagnesianus based on sequences from a paratype specimen of the former. Likewise, the name Cantharellus cibarius var. salmoneus is neotypified and falls in synonymy with C. cibarius.

Wisconsin Chanterelles Revisited and First Indications for Very Wide Distributions of Cantharellus Species in the United States East of the Rocky Mountains

Abstract The authors discuss and illustrate several American collections of Cantharellus that are in one way or another related to species that have previously been reported or described from Wisconsin. These new collections indicate that the potential distribution area of many of these chanterelles may be much larger than generally assumed. Cantharellus deceptivus sp. nov. is described as new cryptic look-alike of C. phasmatis and problems related to the narrow species concept of C. flavus and C. phasmatis are discussed; C. iuventateviridis sp. nov. is described as closest southern relative to C. chicagoensis. Microscopic features of C. chicagoensis and C. flavus are illustrated for the first time. Cantharellus spectaculus is considered a later synonym of C. persicinus on morphological criteria.

Species delimitation in the European species of Clavulina (Cantharellales, Basidiomycota) inferred from phylogenetic analyses of ITS region and morphological data

The identification of the conventionally accepted species of Clavulina (Cantharellales, Basidiomycota) in Europe (Clavulina amethystina, Clavulina cinerea, Clavulina cristata, and Clavulina rugosa) is often difficult and many specimens are not straightforwardly assignable to any of those four species, which is why some authors have questioned their identity. In order to assess the status of those species, a morphological examination was combined with the molecular analysis of the ITS region. The same six major clades were obtained in the Bayesian and parsimony phylogenetic analyses, and all six clades were well-supported at least by one of the analyses. Morphological characters, such as the overall branching pattern, the presence and intensity of grey colour, the cristation of the apices, and basidiospore size and shape were to various extents correlated with the phylogenetic signal obtained from the ITS region. The congruence between the molecular analyses and morphology, rather than geographical origin, suggests the existence of several species that can be delimited using a combined phylogenetic and morphological species recognition. The analyses revealed that C. cristata and C. rugosa are well-delimited species. In contrast, more than one taxa could be subsumed under the names C. amethystina and C. cinerea, the taxonomical complexity of which is discussed. The ITS region is proved to be adequate to separate phylogenetic species of Clavulina.

Two new species of Hydnum with ovoid basidiospores: H. ovoideisporum and H. vesterholtii

Two new species of Hydnum, characterized by slender Hydnum rufescens-like basidiomes and ovoid to broadly ellipsoid basidiospores, are described from the Iberian Peninsula based on morphological and ITS molecular data. Hydnum ovoideisporum is distinguished by pilei with deep orange tones and strong preference for calcareous soil. It is widespread in the Iberian-Mediterranean area. Hydnum vesterholtii is characterized by its ocher to light ocher pileus, and nearly all the collections were made in the Pyrenees. Both ovoid-spored species are monophyletic well supported groups in the maximum parsimony and Bayesian ITS phylogenies, while the remainder of the samples assigned to H. rufescens s.l. and having globose basidiospores split into six well supported clades. The need to typify the name Hydnum rufescens is discussed, and a provisional key is given for the European taxa of Hydnum.

Two new species of Thyronectria from Mediterranean Europe

Two new species of Thyronectria growing in Mediterranean vegetation are described from southern Spain; they are T. giennensis from Quercus ilex ssp. rotundifolia and T. pistaciae from Pistacia lentiscus. Both species are characterized by morphology of sexual and asexual morphs and by DNA data. They have olivaceous to green-brown muriform ascospores and are closely related to T. asturiensis and T. roseovirens, as determined by multigene phylogenetic analyses of a matrix containing six loci (ITS and 28S regions of nuc rDNA, ACT1, RPB1, RPB2, TEF1 and TUB2 genes). We also report that Cucurbitaria bicolor is a synonym of Thyronectria rhodochlora, the type species of Thyronectria.

A preliminary account of the Cucurbitariaceae

Fresh collections, type studies and molecular phylogenetic analyses of a multigene matrix of partial nuSSU-ITS-LSU rDNA, rpb2, tef1 and tub2 sequences were used to evaluate the boundaries of Cucurbitaria in a strict sense and of several related genera of the Cucurbitariaceae. Two species are recognised in Cucurbitaria and 19 in Neocucurbitaria. The monotypic genera Astragalicola, Cucitella, Parafenestella, Protofenestella, and Seltsamia are described as new. Fenestella is here included as its generic type F. fenestrata (= F. princeps), which is lecto- and epitypified. Fenestella mackenzei and F. ostryae are combined in Parafenestella. Asexual morphs of Cucurbitariaceae, where known, are all pyrenochaeta- or phoma-like. Comparison of the phylogenetic analyses of the ITS-LSU and combined matrices demonstrate that at least rpb2 sequences should be added whenever possible to improve phylogenetic resolution of the tree backbone; in addition, the tef1 introns should be added as well to improve delimitation of closely related species.

Species limits and relationships within Otidea inferred from multiple gene phylogenies

The genus Otidea is one of the more conspicuous members of the Pyronemataceae, with high species diversity in hemiboreal and boreal forests. The genus is morphologically coherent and in previous higher-level multi-gene analyses it formed a highly supported monophyletic group. Species delimitation within Otidea is controversial and much confusion has prevailed in the naming of taxa. To provide a phylogenetic hypothesis of Otidea, elucidate species diversity and limits we compiled a four-gene dataset including the nuclear LSU rDNA and three nuclear protein-coding genes (RPB1, RPB2 and EF-1α) for 89 specimens (total 4 877 nucleotides). These were selected from a larger sample of material studied using morphology and 146 ITS (ITS1-5.8S-ITS2) and 168 LSU rDNA sequences to represent the full genetic diversity. Using genealogical concordance phylogenetic species recognition (GCPSR), Bayesian and maximum likelihood analyses of the individual datasets resolved 25 species of Otidea. An additional eight singletons are considered to be distinct species, because they were genetically divergent from their sisters. Sequences of multiple genes were included from 13 holotypes, one neotype and three epitypes. Otidea angusta, O. myosotis and O. papillata f. pallidefurfuracea are nested within O. nannfeldtii, O. leporina and O. tuomikoskii, respectively and are considered synonyms. Otidea cantharella var. minor is shown to be a distinct species. Five new species were discovered: O. oregonensis and O. pseudoleporina for North America; and O. borealis, O. brunneoparva and O. subformicarum for Europe. The analyses of the individual four gene datasets yielded phylogenies that were highly concordant topologically, except for the RPB1 that showed supported conflict for some nodes in Bayesian analysis. Excluding the RPB1 from the combined analyses produced an identical topology to the four-gene phylogeny, but with higher support for several basal nodes and lower support for several shallow nodes. We argue to use the three-gene dataset to retrieve the maximum support for the higher-level relationships in Otidea, but still utilise the signal from the RPB1 for the delimitation and relationships of closely related species. From the four gene regions utilised, EF-1α and RPB1 have the strongest species recognition power, and with higher amplification success EF-1α may serve as the best secondary barcoding locus for Otidea (with ITS being a primary). The phylogeny from the three- and four-gene datasets is fully resolved and strongly supported in all branches but one. Two major clades, as part of six inclusive clades A–F, are identified – and ten subclades within these: A) O. platyspora and O. alutacea subclades, and B) O. papillata, O. leporina, O. tuomikoskii, O. cantharella, O. formicarum, O. unicisa, O. bufonia-onotica and O. concinna subclades. Morphological features in Otidea appear to be fast evolving and prone to shifts, and are poor indicators of higher-level relationships. Nevertheless, a conspicuous spore ornament is a synapomorphy for the O. unicisa subclade (/Otideopsis); all other species in Otidea have smooth or verruculose (in SEM) spores. Exclusively pale to bright yellow apothecia and straight to curved, broadly clavate to distinctly capitate paraphyses are synapomorphies for a restricted O. concinna subclade (/Flavoscypha). The curved to hooked apices of the paraphyses is suggested to be a symplesiomorphic trait for the genus. The reaction of resinous exudates on the outermost excipular cells that coalesce into amber drops in Melzer’s reagent is likely an ancestral state for clade B. We estimate that Otidea consists of 47 species worldwide, based on all available information (including morphology, ITS or LSU sequences, and literature descriptions). Three fifths of the species occur in Europe, with 20 species recognised as endemic. At least 14 species occur in North America and 17 in Asia, with eight and ten species considered endemic to each continent, respectively. Our knowledge about Otidea in Asia is still fragmentary and the diversity likely much higher.

Unraveling the Inocybe praetervisa group through type studies and ITS data: Inocybe praetervisoides sp. nov. from the Mediterranean region

Species in the Inocybe praetervisa group are characterized by producing nodulose to angular basidiospores and a bulbous, marginate, white stipe devoid of any pinkish to reddish tinge. Species delimitation problems and common misinterpretations in the I. praetervisa group have not yet been resolved through type studies and analysis of molecular data. This study seeks to clarify the taxonomy and nomenclature of species around I. praetervisa. Analyses of the nuc rDNA internal transcribed regions (ITS) recovered two major groups within the I. praetervisa group that can be separated on the basis of cystidial morphology. The study of three authentic and topotypic specimens in the Bresadola herbarium revealed that the name I. praetervisa has been misapplied often. The ITS region of one of the specimens was obtained, and this specimen is designated as epitype in support of a lectotype. Inocybe rivularis is demonstrated to be a later synonym of I. praetervisa, while Inocybe phaeocystidiosa is the correct name for the species most often misdetermined as I. praetervisa. Inocybe salicis-herbaceae and I. praetervisa var. flavofulvida are shown to be synonyms of I. phaeocystidiosa based on ITS sequence data from type collections. A new species sister to I. phaeocystidiosa with a Mediterranean distribution is described as I. praetervisoides. Cystidial morphology, distribution of caulocystidia, basidiospore morphology and ecology are shown to be the main diagnostic characters for separating the species. Inocybe praetervisa and I. phaeocystidiosa have a transoceanic distribution in Europe and North America, whereas I. praetervisoides so far is known only from the Mediterranean region.