Systematic revision of the Roseinae clade of Russula, with a focus on eastern North American taxa.

The Roseinae clade is a lineage of the genus Russula primarily composed of species of Russula subsect. Roseinae. Species in this morphologically distinct clade possess a white to pale cream spore print, mild taste, positive reaction to sulfovanillin, and primordial hyphae with acid-resistant crystals in the pileipellis. Here, we present a morphological and phylogenetic assessment that distinguishes seven eastern North American species of the core Roseinae lineage and a new subsection, Russula subsection Albidinae, to accommodate members of the Albida clade. We assign the previously described species R. peckii, R. rubellipes, and R. pseudopeckii to three species-level clades, and three other species, R. cardinalis, R. cordata, and R. rheubarbarina, are described as new. Comparative morphological analyses reveal differences in the conformation of terminal elements in the pileipellis, spore size, hymenial cystidia contents, and pigmentation on the stipe surface as key features to recognize species in the group. Based on the analysis of publicly available data, we recognize a potential total of nine temperate North American species within R. subsect. Roseinae, in addition to four from Central America, two from Europe, and 14 from Asia.

Taxonomy and phylogeny of Exobasidium pentasporium causing witches' broom of Rhododendron species.

Exobasidium pentasporium was first found on Rhododendron kaempferi in Nikko, Tochigi Prefecture, Japan and described only with a brief mentions and illustration of a specimen in 1896. This fungus causes a witches' broom disease of Rhododendron species. To stabilize the concept of this species, the specimen in the protologue was located, carefully examined, and illustrated. In addition, the name was epitypified based on a newly collected topotype specimen. A phylogenetic tree using ITS and LSU sequences showed that our isolates of E. pentasporium grouped with other Exobasidium species on Rhododendron forming a monophyletic clade with strong statistical support and were unrelated to E. nobeyamense, another causal agent of witches' broom disease on Rhododendron species.

More smooth-spored species of Inocybe (Agaricales, Ba sidiomycota): type studies and 12 new species from Europe.

Twelve new species of Inocybe (I. adorabilis, I. comis, I. demetris, I. filiana, I. galactica, I. morganae, I. othini, I. ovilla, I. proteica, I. somae, I. suryana and I. venerabilis) are described from Europe on the basis of detailed morphological and molecular investigation. A portrait of the recently described I. ianthinopes is given. All species are smooth-spored and some pruinose only in the apical part of the stipe, and some on entire length. The new species are compared to 24 type specimens (17 characterized by at least partial ITS sequence data), all of which are described and revised here. Epitypes were selected for two species, I. hirtella and I. sindonia. Based on our studies, we confirm that I. kuehneri and I. sindonia on one hand, and I. subalbidodisca and I. ochroalba on the other, are synonyms and furthermore suggest that I. abietis is synonymous with I. catalaunica, I. exilis with I. rufobrunnea, I. hirtellarum with I. mycenoides, I. lapidicola with I. deianae, I. ochraceolutea with I. sindonia, I. stangliana with I. pelargonium, I. subrubens with I. subhirtella and I. sulfovirescens with I. langei. All of the new species are supported by phylogenetic analyses. Among the 16 previously described species accepted here, 10 are represented by types in the phylogenetic analyses and five by own collections corresponding to the type. Two species, I. eutheloides (remaining doubtful) and I. pallidolutea are only treated morphologically. In summary, we describe as new or verify the taxonomic status and provide or corroborate morphological concepts for 37 smooth-spored species of Inocybe. Citation: Bandini D, Oertel B, Eberhardt U. 2022. More smooth-spored species of Inocybe (Agaricales, Basidiomycota): type studies and 12 new species from Europe. Persoonia 48: 91-149. https://doi.org/10.3767/persoonia.2022.48.03.

Taxonomy and phylogeny of the Erysiphe lonicerae complex (Helotiales, Erysiphaceae) on Lonicera spp.

The phylogeny and taxonomy of powdery mildews, belonging to the genus Erysiphe, on Lonicera species throughout the world are examined and discussed. Phylogenetic analyses revealed that sequences retrieved from Erysiphe lonicerae, a widespread powdery mildew species distributed in the Northern Hemisphere on a wide range of Lonicera spp., constitutes a complex of two separate species, viz., E. lonicerae (s. str.) and Erysiphe ehrenbergii comb. nov. Erysiphe lonicerae occurs on Lonicera spp. belonging to Lonicera subgen. Lonicera (= subgen. Caprifolium and subgen. Periclymenum), as well as L. japonica. Erysiphe ehrenbergii comb. nov. occurs on Lonicera spp. of Lonicera subgen. Chamaecerasus. Phylogenetic and morphological analyses have also revealed that Microsphaera caprifoliacearum (≡ Erysiphe caprifoliacearum) should be reduced to synonymy with E. lonicerae (s. str.). Additionally, Erysiphe lonicerina sp. nov. on Lonicera japonica in Japan is described and the new name Erysiphe flexibilis, based on Microsphaera lonicerae var. flexuosa, is introduced. The phylogeny of Erysiphe ehrenbergii and E. lonicerae as well as other Erysiphe species on honeysuckle is discussed, and a survey of all species, including a key to the species concerned, is provided. Citation: Bradshaw M, Braun U, Götz M, Takamatsu S (2020). Taxonomy and phylogeny of the Erysiphe lonicerae complex (Helotiales, Erysiphaceae) on Lonicera spp. Fungal Systematics and Evolution 7: 49-65. doi: 10.3114/fuse.2021.07.03.

Taxonomical re-examination of the genus Neofusicoccum in Japan.

Neofusicoccum is a genus of plant pathogenic fungi associated with various woody plants. Since Neofusicoccum has very similar morphological characteristics to the genus Botryospaheria, molecular phylogenetic analysis is essential to determine its taxonomic position. In Japan, a comprehensive taxonomic study of the genus Neofusicoccum has not been conducted. To elucidate the species diversity in Japan, we reexamined Japanese isolates of Neofusicoccum based on their morphology and molecular phylogenetic relationships, using the internal transcribed spacer (ITS) regions rpb2, tef1-α, and tub2. The Japanese isolates were divided into five clades recognized as the species. These species were N. parvum, other Neofusicoccum spp., and three new species proposed in this study, N. hyperici, N. miyakoense, and N. okinawaense. Furthermore, Physalospora laricina, which causes shoot blight of larch (Larix spp.), was transferred to the genus Neofusicoccum, and we propose its epitype and ex-epitype isolate.

Phylogenetic placement of Iodosphaeriaceae (Xylariales, Ascomycota), designation of an epitype for the type species of Iodosphaeria, I. phyllophila, and description of I. foliicola sp. nov.

The Iodosphaeriaceae is represented by the single genus, Iodosphaeria, which is composed of nine species with superficial, black, globose ascomata covered with long, flexuous, brown hairs projecting from the ascomata in a stellate fashion, unitunicate asci with an amyloid apical ring or ring lacking and ellipsoidal, ellipsoidal-fusiform or allantoid, hyaline, aseptate ascospores. Members of Iodosphaeria are infrequently found worldwide as saprobes on various hosts and a wide range of substrates. Only three species have been sequenced and included in phylogenetic analyses, but the type species, I. phyllophila, lacks sequence data. In order to stabilize the placement of the genus and family, an epitype for the type species was designated after obtaining ITS sequence data and conducting maximum likelihood and Bayesian phylogenetic analyses. Iodosphaeria foliicola occurring on overwintered Alnus sp. leaves is described as new. Five species in the genus form a well-supported monophyletic group, sister to the Pseudosporidesmiaceae in the Xylariales. Selenosporella-like and/or ceratosporium-like synasexual morphs were experimentally verified or found associated with ascomata of seven of the nine accepted species in the genus. Taxa included and excluded from Iodosphaeria are discussed.

Redefining species limits in the Fusarium fujikuroi species complex.

The Fusarium fujikuroi species complex (FFSC) includes more than 60 phylogenetic species (phylospecies) with both phytopathological and clinical importance. Because of their economical relevance, a stable taxonomy and nomenclature is crucial for species in the FFSC. To attain this goal, we examined type specimens and representative cultures of several species by employing morphology and phylogenetic analyses based on partial gene fragments of the translation elongation factor 1-alpha (tef1), beta-tubulin (tub2), calmodulin (cmdA), RNA polymerase largest subunit (rpb1) and RNA polymerase II second largest subunit (rpb2). Based on these results three new species were delimited in the FFSC. Two of these phylospecies clustered within the African clade, and one in the American clade. Epitypes were also designated for six previously described FFSC species including F. proliferatum and F. verticillioides, and a neotype designated for F. subglutinans. Furthermore, both F. acutatum and F. ophioides, which were previously invalidly published, are validated. Citation: Yilmaz N, Sandoval-Denis M, Lombard L, et al. 2021. Redefining species limits in the Fusarium fujikuroi species complex. Persoonia 46: 129-162. https://doi.org/10.3767/persoonia.2021.46.05.

Taxonomy and phylogeny of cercosporoid ascomycetes on Diospyros spp. with special emphasis on Pseudocercospora spp.

A worldwide survey of cercosporoid ascomycete species on hosts of the genus Diospyros (persimmon) with key to the species based on characters in vivo is provided. Special emphasis is placed on species of the genus Pseudocercospora, which are in part also phylogenetically analysed, using a multilocus approach. Species of the latter genus proved to be very diverse, with a remarkable degree of cryptic speciation. Seven new species are described (Pseudocercospora diospyri-japonicae, P. diospyriphila, P. ershadii, P. kakiicola, P. kobayashiana, and P. tesselata), and two new names are introduced [P. kakiigena (≡ Cylindrosporium kaki, non Pseudocercospora kaki), and Zasmidium diospyri-hispidae (≡ Passalora diospyri, non Zasmidium diospyri)]. Six taxa are lectotypified (Cercospora atra, C. diospyri, C. diospyri var. ferruginea, C. flexuosa, C. fuliginosa, C. kaki), and Pseudocercospora kaki is epitypified.

Dinastridium verrucosum Baumeister from Bavaria (Germany) is a Borghiellacean Dinophyte (†Suessiales).

Phytodinialean dinophytes are poorly known at present and their phylogenetic relationships largely elusive. Historical names of microscopic species are frequently ambiguous, and a reliable application is impeded although crucial to fully explore the biology of organisms. We collected material close to the type locality of a historical species, namely Dinastridium verrucosum, and established eight strains for morphological and molecular studies. The motile cells showed an obovate shape in outline and were dorso-ventrally slightly flattened. They were orange-brown in colour and had a descending cingulum. In light microscopy, an eyespot was discerned in a few monadoid cells in the central region of the sulcus. Furthermore, a morphologically characteristic, 4-6µm long apical furrow was observed on the episome of the cells in SEM. Older cultivated material further exhibited coccoid cells of irregular shape, with wart-like protuberances and covered by a more or less extensive mucilage. This morphology is indistinguishable from the lectotype of D. verrucosum. In a molecular phylogeny, the species was placed in the Borghiellaceae (†Suessiales). As taxonomic result, we epitypify the historical name, D. verrucosum, and perform the necessary combination to Borghiella.

Dictyosphaerium-like morphotype in terrestrial algae: what is Xerochlorella (Trebouxiophyceae, Chlorophyta)?1.

Several strains of terrestrial algae isolated from biological soil crusts in Germany and Ukraine were identified by morphological methods as the widely distributed species Dictyosphaerium minutum (=Dictyosphaerium chlorelloides). Investigation of the phylogeny showed their position unexpectedly outside of Chlorellaceae (Trebouxiophyceae) and distantly from Chlorella chlorelloides, to which this taxon was attributed after revision of the genus Chlorella based on an integrative approach. SSU rRNA phylogeny determined the position of our strains inside a clade recently described as a new genus of the cryptic alga Xerochlorella olmiae isolated from desert biological soil crusts in the United States. Investigation of the morphology of the authentic strain of X. olmiae showed Dictyosphaerium-like morphology, as well as some other characters, common for our strains and morphospecies D. minutum. The latter alga was described as terrestrial and subsequently united with the earlier described aquatic representative D. chlorelloides because of their similar morphology. The revision of Chlorella mentioned above provided only one aquatic strain (D. chlorelloides), which determined its position in the genus. But terrestrial strains of the morphospecies were not investigated phylogenetically. Our study showed that the terrestrial D. minutum is not related to the morphologically similar D. chlorelloides (=Chlorella chlorelloides, Chlorellaceae), and instead represented a separate lineage in the Trebouxiophyceae, recently described as genus Xerochlorella. Therefore, revision of Xerochlorella is proposed, including nomenclatural combinations, epitypifications, and emendations of two species: X. minuta and X. dichotoma. New characters of the genus based on investigation of morphology and ultrastructure were determined.

New record of the rare genus Crinalium Crow (Oscillatoriales, Cyanobacteria) from sand dunes of the Baltic Sea, Germany: epitypification and emendation of Crinalium magnum Fritsch et John based on an integrative approach.

Representatives of the Gomontiellaceae (Oscillatoriales) are rare and hence unstudied cyanobacteria with unusual morphology, distributed in terrestrial and aquatic habitats all over the world. Investigation of the group based on an integrative approach is only beginning, and to understand the actual biodiversity and ecology, a greater number of cultivated strains is necessary. However, some ecological traits of these cyanobacteria (e.g. low population densities, the absence of conspicuous growth in nature) led to methodological difficulties during isolation in culture. One species in the family Gomontiellaceae, Crinalium magnum Fritsch et John, is characterized by prominent wide and flattened trichomes, and represented by the non-authentic strain SAG 34.87. Detailed previous investigation of this strain clearly showed its morphological discrepancy with the original description of C. magnum and the genus Crinalium in general. The new isolate from maritime sand dunes of the Baltic Sea coast (Germany), however, revealed morphological characters completely corresponding with the diagnosis of C. magnum. Phylogenetic analysis based on 16S rRNA sequences indicated a position of the new strain inside Gomontiellaceae. Both morphology and ultrastructure of the strain are congruous with characters of the family. Epitypification and emendation of C. magnum are proposed since the ecology and habitat of the original strain are congruent with the type locality of this rare species (sand, Irish Sea coast, North Wales, UK). We expanded the description of C. magnum by details of the filament development and specified dimensional ranges for trichomes and cells, as well as by new data about the transversely striated structure of mucilaginous sheath.

Phylogenetic relationships of Phaeochorellaparinarii and recognition of a new family, Phaeochorellaceae (Diaporthales).

Species of Phaeochorella are biotrophic leaf parasites with a tropical distribution, traditionally accepted in the family Phyllachoraceae, Phyllachorales in classifications based on morphological characters. Phylogenetic evidence presented here resolves the relationship of Phaeochorella within the Sordariomycetes, based on a multilocus analysis of partial nuc rDNA large subunit (28S) and internal transcribed spacers (ITS1-5.8S-ITS2 = ITS), the DNA-directed RNA polymerase II second largest subunit (RPB2), and the translation elongation factor 1-α (TEF1-α) gene. Phylogenetic analyses indicate that Phaeochorella belongs to the Diaporthales rather than the Phyllachorales. Phaeochorella parinarii, the type species of the genus, present on native hosts from the Brazilian Cerrado, forms a unique clade with a species of Phaeoappendicospora with high support. Thus, a new family, Phaeochorellaceae, Diaporthales, including both genera, is herein proposed. With the exception of P. parinarii and P. zonata, all other species in Phaeochorella (P. artocarpi, P. ciliata, P. machaerii) were excluded from the genus.

Phylogeny and taxonomy of the genus Tubakia s. lat.

The genus Tubakia is revised on the basis of morphological and phylogenetic data. The phylogenetic affinity of Tubakia to the family Melanconiellaceae (Diaporthales) was recently postulated, but new analyses based on sequences retrieved from material of the type species of Tubakia, T. dryina, support a family of its own, viz. Tubakiaceae fam. nov. Our phylogenetic analyses revealed the heterogeneity of Tubakia s. lat. which is divided into several genera, viz., Tubakia s. str., Apiognomonioides gen. nov. (type species: Apiognomonioides supraseptata), Involutiscutellula gen. nov. (type species: Involutiscutellula rubra), Oblongisporothyrium gen. nov. (type species: Oblongisporothyrium castanopsidis), Paratubakia gen. nov. (type species: Paratubakia subglobosa), Racheliella gen. nov. (type species: Racheliella wingfieldiana sp. nov.), Saprothyrium gen. nov. (type species: Saprothyrium thailandense) and Sphaerosporithyrium gen. nov. (type species: Sphaerosporithyrium mexicanum sp. nov.). Greeneria saprophytica is phylogenetically closely allied to Racheliella wingfieldiana and is therefore reallocated to Racheliella. Particular emphasis is laid on a revision and phylogenetic analyses of Tubakia species described from Japan and North America. Almost all North American collections of this genus were previously referred to as T. dryina s. lat., which is, however, a heterogeneous complex. Several new North American species have recently been described. The new species Sphaerosporithyrium mexicanum, Tubakia melnikiana and T. sierrafriensis, causing leaf spots on several oak species found in the North-Central Mexican state Aguascalientes and the North-Eastern Mexican state Nuevo León, are described, illustrated, and compared with similar species. Several additional new species are introduced, including Tubakia californica based on Californian collections on various species of the genera Chrysolepis, Notholithocarpus and Quercus, and T. dryinoides, T. oblongispora, T. paradryinoides, and Paratubakia subglobosoides described on the basis of Japanese collections. Tubakia suttoniana nom. nov., based on Dicarpella dryina, is a species closely allied to T. californica and currently only known from Europe. Tubakia dryina, type species of Tubakia, is epitypified, and the phylogenetic position and circumscription of Tubakia are clarified. A revised, supplemented key to the species of Tubakia and allied genera on the basis of conidiomata is provided.

Epitypification with an emended description of Tropidia connata (Orchidaceae, Epidendroideae, Tropidieae).

We found several specimens of Tropidia connata, a mycoheterotrophic orchid from Borneo, with features which have never been described in any of the existing literature, namely subterranean tubers. We mainly focus on the importance of the subterranean structures in comparison with the mycoheterotrophic genus Kalimantanorchis from the tribe Tropidieae. This finding of the tuberous structure gives a new insight into the classification of mycoheterotrohic species of Tropidieae and might affect the generic placement of Kalimantanorchis. We made a detailed study on the newly discovered specimens as well as the type, and found more diagnostic characters of T. connata than the previous description. Considering that the type specimen lacks the whole tuberous character, we consequently designate an epitype with a drawing and emend the description.

Phylogenetic reassessment of the Chaetomium globosum species complex.

Chaetomium globosum, the type species of the genus, is ubiquitous, occurring on a wide variety of substrates, in air and in marine environments. This species is recognised as a cellulolytic and/or endophytic fungus. It is also known as a source of secondary metabolites with various biological activities, having great potential in the agricultural, medicinal and industrial fields. On the negative side, C. globosum has been reported as an air contaminant causing adverse health effects and as causal agent of human fungal infections. However, the taxonomic status of C. globosum is still poorly understood. The contemporary species concept for this fungus includes a broadly defined morphological diversity as well as a large number of synonymies with limited phylogenetic evidence. The aim of this study is, therefore, to resolve the phylogenetic limits of C. globosum s.str. and related species. Screening of isolates in the collections of the CBS-KNAW Fungal Biodiversity Centre (The Netherlands) and the China General Microbiological Culture Collection Centre (China) resulted in recognising 80 representative isolates of the C. globosum species complex. Thirty-six species are identified based on phylogenetic inference of six loci, supported by typical morphological characters, mainly ascospore shape. Of these, 12 species are newly described here. Additionally, C. cruentum, C. mollipilium, C. rectum, C. subterraneum and two varieties of C. globosum are synonymised under C. globosum s.str., and six species are resurrected, i.e. C. angustispirale, C. coarctatum, C. cochliodes, C. olivaceum, C. spiculipilium and C. subglobosum. Chaetomium ascotrichoides is segregated from C. madrasense and the genus name Chaetomidium is rejected. Five species, including C. globosum s.str., are typified here to stabilise their taxonomic status. A further evaluation of the six loci used in this study as potential barcodes indicated that the 28S large subunit (LSU) nrDNA and the internal transcribed spacer regions and intervening 5.8S nrRNA (ITS) gene regions were unreliable to resolve species, whereas ß-tubulin (tub2) and RNA polymerase II second largest subunit (rpb2) showed the greatest promise as DNA barcodes for differentiating Chaetomium species. This study provides a starting point to establish a more robust classification system for Chaetomium and for the Chaetomiaceae.

Species limits in Diaporthe: molecular re-assessment of D. citri, D. cytosporella, D. foeniculina and D. rudis.

Species of Diaporthe are important plant pathogens of a wide range of hosts worldwide. In the present study the species causing melanose and stem end rot diseases of Citrus spp. are revised. Three species of Diaporthe occurring on Citrus are characterised, including D. citri, D. cytosporella and D. foeniculina. Morphology and phylogenetic analyses of the complete nuclear ribosomal internal transcribed spacer regions and partial sequences of actin, beta-tubulin, calmodulin and translation elongation factor 1-α were used to resolve species on Citrus and related Diaporthe species. Diaporthe citri occurs on Citrus throughout the Citrus-growing regions of the world. Diaporthe cytosporella is found on Citrus in Europe and California (USA). Diaporthe foeniculina, including the synonym D. neotheicola, is recognised as a species with an extensive host range including Citrus. Diaporthe medusaea, a name widely used for D. citri, was determined to be a synonym of D. rudis, a species with a broad host range. Diaporthe citri is delimited based on molecular phylogenetic analysis with the inclusion of the conserved ex-type and additional collections from different geographic locations worldwide. Diaporthe cytosporella, D. foeniculina and D. rudis are epitypified, fully described and illustrated with a review of all synonyms based on molecular data and morphological studies. Newly designed primers are introduced to optimise the amplification and sequencing of calmodulin and actin genes in Diaporthe. A discussion is provided of the utility of genes and the need for multi-gene phylogenies when distinguishing species of Diaporthe or describing new species.

Alessioporus and Pulchroboletus (Boletaceae, Boletineae), two novel genera for Xerocomus ichnusanus and X. roseoalbidus from the European Mediterranean basin: molecular and morphological evidence.

Alessioporus and Pulchroboletus are proposed as new monotypic genera to accommodate the thermo-xerophilic European species Xerocomus ichnusanus and X. roseoalbidus respectively. The present research focused on both morphological features and multigene molecular phylogeny (nrITS, nrLSU, tef-1α datasets) to elucidate the taxonomic status of these two rare Mediterranean boletes and delineate a natural classification within the family Boletaceae. Macro- and microscopic descriptions of the two species based on inclusive taxon sampling are provided and supported by line drawings of the main anatomical features. Phylogenetic relationships, ecology, geographical distribution and delimitation from the most closely allied taxa also are highlighted. In addition, epitype specimens are selected for both species.

Circumscription of the anthracnose pathogens Colletotrichum lindemuthianum and C. nigrum.

The anthracnose pathogen of common bean (Phaseolus vulgaris) is usually identified as Colletotrichum lindemuthianum, while anthracnose of potato (Solanum tuberosum), peppers (Capsicum annuum), tomato (S. lycopersicum) and several other crop plants is often attributed to C. coccodes. In order to study the phylogenetic relationships of these important pathogens, we conducted a multigene analysis (ITS, ACT, TUB2, CHS-1, GAPDH) of strains previously identified as C. lindemuthianum, C. coccodes and other related species, as well as representative species of the major Colletotrichum species complexes. Strains of C. lindemuthianum belonged to a single clade; we selected an authentic specimen as lectotype, and an appropriate specimen and culture from the CBS collection to serve as epitype. Two clades were resolved within C. coccodes s. lat. One clade included the ex-neotype strain of C. coccodes on Solanum, while an epitype was selected for C. nigrum, which represents the oldest name of the second clade, which occurs on Capsicum, Solanum, as well as several other host plants. Furthermore, we recognized C. lycopersici as a synonym of C. nigrum, and C. biologicum as a synonym of C. coccodes.

Correct names for some of the closest relatives of Carica papaya: A review of the Mexican/Guatemalan genera Jarilla and Horovitzia.

Using molecular data, we recently showed that Carica papaya L. is sister to a Mexican/Guatemalan clade of two genera, Jarilla Rusby with three species and Horovitzia V.M. Badillo with one. These species are herbs or thin-stemmed trees and may be of interest for future genomics-enabled papaya breeding. Here we clarify the correct names of Jarilla heterophylla (Cerv. ex La Llave) Rusby and Jarilla caudata (Brandegee) Standl., which were confused in a recent systematic treatment of Jarilla (McVaugh 2001). We designate epitypes for both, provide weblinks to type specimens, a key to the species of Jarilla and Horovitzia, and notes on their habitats and distribution.

A systematic account of the genus Plagiostoma (Gnomoniaceae, Diaporthales) based on morphology, host-associations, and a four-gene phylogeny.

Members of the genus Plagiostoma inhabit leaves, stems, twigs, and branches of woody and herbaceous plants predominantly in the temperate Northern Hemisphere. An account of all known species of Plagiostoma including Cryptodiaporthe is presented based on analyses of morphological, cultural, and DNA sequence data. Multigene phylogenetic analyses of DNA sequences from four genes (ß-tubulin, ITS, rpb2, and tef1-α) revealed eight previously undescribed phylogenetic species and an association between a clade composed of 11 species of Plagiostoma and the host family Salicaceae. In this paper these eight new species of Plagiostoma are described, four species are redescribed, and four new combinations are proposed. A key to the 25 accepted species of Plagiostoma based on host, shape, and size of perithecia, perithecial arrangement in the host, and microscopic characteristics of the asci and ascospores is provided. Disposition of additional names in Cryptodiaporthe and Plagiostoma is also discussed.