Karl-Henrik Larsson

University of Oslo

Phellodon is a globally distributed genus of stipitate hydnoid fungi recognised by a white spore print and an ectomycorrhizal life strategy. In Europe, many Phellodon species have declining populations and are used as indicators of forests with high conservation values. However, their use in this context and the correct assessment of their extinc...

DNA-based phylogenetic inference has shown that many morphological traits, once considered taxonomically relevant, are the result of convergent evolution. In this study, we analyze Kneiffiella , a genus of corticioid and polyporoid wood-inhabiting basidiomycetes in the order Hymenochaetales . A multi-gene-based phylogeny demonstrates that Kneiffiel...

The ectomycorrhizal genus Piloderma (Atheliales, Basidiomycota) is studied using morphological andmolecular methods. Seven new species are identified and described, viz. P. cinicola, P. craurum, P. egens, P.exiguum, P. humile, P. ochraceum, and P. rallum, bringing the total number of accepted species to 13. All newspecies are supported by ITS seque...

Based on seven-and three-gene datasets, we discuss four alternative approaches for a reclassification of Fomitopsidaceae (Polyporales, Basidiomycota). After taking into account morphological diversity in the family, we argue in favour of distinguishing three genera only, viz. Anthoporia, Antrodia and Fomitopsis. Fomitopsis becomes a large genus wit...

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 digit...

Cerrenaceae is a small family of polypores and hydnoid fungi in the order Polyporales (Basidiomycota). The family consists of white-rot fungi, some of which are serious tree pathogens. Combining morphological evidence with a phylogenetic dataset of six genetic markers, we revise generic concepts in the family and propose a seven-genus classificatio...

The new species Steccherinum filiferum, from Puerto Rico and Amazonian rainforests of Ecuador, is described. It is characterized by effused basidiomata with hyphal cords, a monomitic hyphal system, simple-septate hyphae, and minute hymenophoral aculei with encrusted, septate, Candelabrochaete-like cystidia. Because Odontia laxa [≡ Odonticium laxum]...

Lagarobasidium cymosum is a rare corticioid species with characteristic morphology different from other Lagarobasidium species. We used nuc 5.8S rDNA, nuc 28S rDNA, and mt 12S rDNA loci to infer the phylogenetic position of L. cymosum. Our analyses suggest that it belongs to Xylodon but is not closely related to any of the other taxa referred to La...

Allophlebia is proposed as a new genus in Meruliaceae based on morphological characters and molecular data. The genus, so far monotypic, is typified by Peniophora ludoviciana and the new combination A. ludoviciana is proposed. The type species is characterized by a resupinate basidioma, a monomitic hyphal system with clamp connections, two types of...

With the change to one scientific name for fungal taxa, generic names typified by species with sexual or asexual morph types are being evaluated to determine which names represent the same genus and thus compete for use. In this paper generic names of the Agaricomycotina ( Basidiomycota ) were evaluated to determine synonymy based on their type. Fo...

Polyozellus and Pseudotomentella are two genera of closely related, ectomycorrhizal fungi in the order Thelephorales ; the former stipitate and the latter corticioid. Both are widespread in the Northern Hemisphere and many species from both genera seem to be restricted to old growth forest. This study aimed to: a) identify genetic regions useful in...

Taxonomy of Basidiodendron caesiocinereum complex is revised based on morphological and molecular methods (with the use of nc LSU rDNA, ITS and TEF1 regions). The basidiospore ornamentation is justified as a key morphological character for the species recognition in the group. As redefined here, B. caesiocinereum is an angiosperm-dwelling species w...

To date, Megalocystidium leucoxanthum, a corticioid fungus originally described from the Italian Alps, was considered as a widely distributed species inhabiting numerous angiosperm hosts in the northern hemisphere. Its specimens collected in different geographic areas and from various host species revealed a high morphological variability and thus...

Allophlebia is proposed as a new genus in Meruliaceae based on morphological characters and molecular data. The genus is typified by Peniophora ludoviciana and the new combination A. ludoviciana is proposed. The genus is so far monotypic. The type species is characterized by a resupinate basidioma, a monomitic hyphal system with clamp connections,...

Four new Hydnellum species are described. Hydnellum roseoviolaceum sp. nov. grows in dry pine heaths on acidic, sandy soil. It is close to H. fuligineoviolaceum , another pine-associated species, but differs by smaller spores, an initially rose-coloured instead of violet flesh in fresh basidiomata and a mild taste. Hydnellum scabrosellum sp. nov. g...

One Tomentella and two Pseudotomentella species are described from alpine areas of Sweden and Norway. Tomentella viridibasidia sp. nov. is genetically closely related to T. bryophila, but is morphologically most similar to T. olivascens and T. stuposa. Pseudotomentella badjelanndana sp. nov. and P. sorjusensis sp. nov. belong to the P. tristis grou...

The taxonomy of Sistotremastrum (Trechisporales, Basidiomycota) is revised based on morphology and DNA data. The genus is shown to be polyphyletic, and therefore it is split into two units – Sistotremastrum s. str. and Sertulicium, gen. nov. (typified with Corticium niveocremeum). Sistotremastrum s. str. is retained for eleven species of which eigh...

Atheliales (Agaricomycetes, Basidiomycota) is an order mostly composed of corticioid fungi, containing roughly 100 described species in approximately 20 genera. Members exhibit remarkable ecological diversity, including saprotrophs, ectomycorrhizal symbionts, facultative parasites of plants or lichens, and symbionts of termites. Ectomycorrhizal mem...

Three new species of Trechispora from Brazil, T. copiosa, T. gelatinosa, and T. termitophila, are described and illustrated. The new species are microscopically similar to the known Trechispora species, but differ by having coralloid basidiomata and would traditionally have been placed in Scytinopogon. Phylogenetic analyses based on nuc rDNA ITS1-5...

There were errors in the name of author László G. Nagy and in affiliation no. 31 in the original publication. The original article has been corrected.

Here, we describe the taxon hypothesis (TH) paradigm, which covers the construction, identification, and communication of taxa as datasets. Defining taxa as datasets of individuals and their traits will make taxon identification and most importantly communication of taxa precise and reproducible. This will allow datasets with standardized and atomi...

Collections from field expeditions to the Atlantic Forest and to Amazonia in Brazil and revision of herbarium material revealed the presence of Trechispora specimens that could not be assigned to any described species. Phylogenetic analysis based on nuc rDNA ITS1-5.8S-ITS2 (ITS) and nuc 28S rDNA (28S) regions confirmed that these specimens belong t...

To date, Basidiodendron luteogriseum, the generic type of Basidiodendron (Auriculariales, Basidiomycota) has been treated as a synonym of B. eyrei. Our data show they are not conspecific. The identity of other members of the B. eyrei complex, i.e., B. deminutum and B. grandinioides, is clarified based on morphological and DNA data, and 10 new speci...

The cryptic lifestyle of most fungi necessitates molecular identiication of the guild in environmental studies. Over the past decades, rapid development and afordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about f...

A checklist of corticioid fungi (Agaricomycetes, Basidiomycota) from Brazil

Species boundaries and geographic distribution of corticioid fungi (resupinate Basidiomycota) are often poorly known. Our recent study on Subulicystidium showed that species diversity in this genus is at least twice as high as previously recognized. This re-estimation of the species diversity was based on a study of only a part of the genus. The pr...

The North European species of Elaphomyces section Elaphomyces ( Eurotiales , Pezizomycotina ) are studied. Three new species, E. citrinopapillatus , E. pusillus , and E. roseoviolaceus are introduced and verified by morphology and sequence data from ITS, nuclear LSU, mitochondrial SSU, and β-tubulin. A lectotype for Elaphomyces granulatus is select...

The following new combinations are proposed: Bourdotiella crustula, basionym Odontia crustula, Chaetodermella incrassata, basionym Peniophora incrassata, Crustoderma cryptocallimon, basionym Hyphoderma cryptocallimon, Dentipellis lindtneri, basionym Gloeocystidium lindtneri, Fibricium subodoratum, basionym Corticium subodoratum, Gloeocystidiellum g...

Two new species of Helicogloea, H. aseptata and H. insularis, are described based on collections from North Europe. In addition, morphological flexibility and host specificity of H. dryina, H. sebacea and H. subardosiaca are discussed. A key for teleomorphic Helicogloea spp. found in Europe is provided.

The poster shows the results of our work done in 2015-2019 on clarifying the species boundaries and distribution patterns in corticioid fungi of the genus Subulicystidium (Fungi, Basidiomycota, Agaricomycetes)

The taxonomy of Protomerulius and Heterochaetella is revised based on DNA data and morphological evidence, and their type species, P. brasiliensis and H. dubia, are proved to be congeneric. As a consequence, H. dubia and related species, of which four are described as new, are placed in Protomerulius. Heterochaete microspora is also combined in Pro...

Most known brown rot-producing species of Polyporales belong to the so-called "Antrodia clade" that largely consists of poroid species. In this study, we use three genetic markers to revise Antrodia s. str., the core group of this clade. We show that a corticioid species with a smooth hymenophore, Phlebia griseoflavescens, belongs to Antrodia s. st...

The genus Heterochaete (Auriculariales, Basidiomycota) is traditionally defined as comprising resupinate fungal species with sterile spines (hyphal pegs) that are distributed on hymenial surface. Recent DNA-based studies have indicated that Heterochaete is polyphyletic, although the correct taxonomic positions of many species under this genus remai...

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetomella pseudocircinoseta and Coniella pseudodiospyri on Eucalyptus microcorys leaves, Cladophialophora eucalypti, Teratosphaeria dunnii and Vermiculariopsiella dunnii on Eucalyptus dunnii leaves, Cylindrium grande and Hypsotheca eucalypto...

UNITE (https://unite.ut.ee; Nilsson et al. 2018) is an international community of scientists and citizen scientists established in 2001. The ambition of UNITE is to develop: 1) datasets and tools for robust and reproducible molecular identification; 2) Persistent Identifiers based system for the communicating fungal species. Datasets of the nuclear...

DNA sequences from the nuclear LSU and ITS regions were used for phylogenetic analyses of Thelephorales with a focus on the stipitate hydnoid genera Hydnellum and Sarcodon. Analyses showed that Hydnellum and Sarcodon are distinct genera but that the current division, based on basidioma texture, makes Sarcodon paraphyletic with respect to Hydnellum....

The genus name Hydnoporia is reinstated to encompass the Hymenochaete tabacina group currently addressed to Pseudochaete (illegitimate genus) or Hymenochaetopsis. Identity of the type species of Hydnoporia, Sistotrema fuscescens (= Hydnoporia olivacea in current sense), is clarified, and a lectotype is selected. In total, 12 species are combined in...

Morphological and DNA data show that effused representatives of the Auriculariales (Basidiomycota) with sphaeropedunculate basidia belong to eleven genera of which seven are dealt with in this study. Among them, Myxarium is the largest genus containing 21 accepted species of which nine are reintroduced below and five are described as new. Protodont...

Stypella vermiformis is a heterobasidiomycete producing minute gelatinous basidiocarps on rotten wood of conifers in Northern Hemisphere. In the current literature, S. papillata, the genus type of Stypella (described from Brazil), is treated as a taxonomic synonym of S. vermiformis. In the present paper, we revise the type material of S. papillata...

P.tristis is an ectomycorrhizal, corticioid fungus whose name is frequently assigned to collections of basidiomata as well as root tip and soil samples from a wide range of habitats and hosts across the northern hemisphere. Despite this, its identity is unclear; eight heterotypic taxa have in major reviews of the species been considered synonymous...

In the present paper, we select a neotype for Tremella cerasi and prove that it is conspecific with Ditangium insigne (the genus type of Ditangium). We argue that Ditangium should be restored as a correct genus for T. cerasi, while the currently used generic name Craterocolla is to be treated as its younger synonym. Morphological, ecological and ge...

UNITE (https://unite.ut.ee/) is a web-based database and sequence management environment for the molecular identification of fungi. It targets the formal fungal barcode-the nuclear ribosomal internal transcribed spacer (ITS) region-and offers all ∼1 000 000 public fungal ITS sequences for reference. These are clustered into ∼459 000 species hypothe...

Lagarobasidium is a small genus of wood-decaying basidiomycetes in the order Hymenochaetales. Molecular phylogenetic analyses have either supported Lagarobasidium as a distinct taxon, or indicated that it should be subsumed under Xylodon, a genus that covers the majority of species formerly placed in Hyphodontia. We used sequences from the ITS and...

The taxonomy of the corticioid fungi from the class Atractiellomycetes (Pucciniomycotina, Basidiomycetes) currently addressed to the genus Helicogloea, is revised based on morphological and nuclear ribosomal DNA (ITS and LSU) data. The genus is restricted to 25 species with semitranslucent, gelatinous basidiocarps lacking differentiated cystidia an...