Gregory M. Mueller

• Ph.D.
• Chief Scientist & Negaunee Foundation Vice President of Science at Chicago Botanic Garden

Fungi comprise approximately 20% of all eukaryotic species and are connected to virtually all life forms on Earth. Yet, their diversity remains contentious, their distribution elusive, and their conservation neglected. We aim to flip this situation by synthesizing current knowledge. We present a revised estimate of 2–3 million fungal species with a...

The nuclear ribosomal internal transcribed spacer (nrITS) region has been widely used in fungal diversity studies. Environmental metabarcoding has increased the importance of the fungal DNA barcode in documenting fungal diversity and distribution. The DNA barcode gap is seen as the difference between intra- and inter-specific pairwise distances in...

In January 2023, the IUCN Species Survival Commission (SSC) created a new specialist group to focus on the conservation of Brazilian fungi: the IUCN SSC Brazil Fungal Specialist Group (iucnbrazfun.com, @iucnfungibrazil and iucnssc_fungibrazil). As a megadiverse country with key biodiversity hotspots, Brazil and its fauna, flora and funga face numer...

Since 1970, there has been an overall decline in wildlife populations in the order of 52%. Freshwater species populations have declined by 76%; species populations in Central and South America have declined by 83%; and in the Indo-Pacific by 67%. These are often not complete extinctions, but large declines in the numbers of animals in each species,...

Fungal species are not immune to the threats facing animals and plants and are thus also prone to extinction. Yet, until 2015, fungi were nearly absent on the IUCN Red List. Recent efforts to identify fungal species under threat have significantly increased the number of published fungal assessments. The 597 species of fungi published in the 2022-1...

Suillus is a genus of ectomycorrhizal fungi associated almost exclusively with Pinaceae. Lack of sample collections in East Asia and unresolved basal phylogenetic relationships of the genus are the major obstacles for better understanding the Suillus evolution. A resolved phylogeny of Suillus representing global diversity was achieved by sequencing...

Exotic pine trees are often introduced to novel places worldwide. How exotic pines interact with local microbial communities, such as symbiotic ectomycorrhizal (ECM) fungi, during early establishment compared to interactions by their native counterparts remains to be examined in detail. In this study, native masson pine (Pinus massoniana) and exoti...

Since 2013 there have been 22 new species of Laccaria described worldwide. Only three of these represent species from the neotropics. In Panama, Laccaria is abundant in monodominant Oreomunnea mexicana (Juglandaceae) forests based on sporocarps and environmental sequencing of roots. This study uses a combination of morphological and phylogenetic ev...

Background and Aims Introducing exotic tree species for afforestation out of their natural range may alter the local ectomycorrhizal (ECM) fungal communities. The potential functional consequences shaped by exotic trees with recruited local ECM fungi rather than native trees remain unclear. This study examined (a) whether the composition and extrac...

In this study, the taxonomic diversity of the Xylodon raduloides species complex (Hymenochaetales, Basidiomycota) is examined. Specimens were studied using an integrative taxonomic approach that includes molecular phylogenetic and morphological analyses, and environmental niche comparisons. Four different species were found inside the Xylodon radul...

A new species in the genus Russula from mixed coniferous forest of District Shangla, Khyber Pakhtunkhwa, Pakistan is described and illustrated. Phylogenetic data derived from DNA sequences of nuclear ribosomal internal transcribed spacer (ITS), along with morphological characterizations, indicate the species is novel. Russula shanglaensis sp. nov....

The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names...

Two new species in the mushroom genus Amanita are described and illustrated from Northwestern Pakistan. Phylogenetic data derived from nuclear ribosomal ITS and LSU regions along with morphological characterizations indicate these species are novel. Amanita cinis is a member of section Roanokenses, while A. olivovaginata is representative of sectio...

The protocol for sampling conspicuous macrofungi using fixed-size plots.

Exotic non-native Pinus species have been widely planted or become naturalized in many parts of the world. Pines rely on ectomycorrhizal (ECM) fungi mutualisms to overcome barriers to establishment, yet the degree to which host specificity and edaphic preferences influence ECM community composition remains poorly understood. In this study, we used...

Species of Laccaria (Hydnangiaceae, Basidiomycota) are important in forest ecosystems as ectomycorrhizal fungi. Nine of the 75 described Laccaria species worldwide been reported from Korea. Most of these have European and North American names, and their identities are based solely on morphological features. To evaluate the taxonomy of Korean Laccar...

Notes S1 Laccaria Systematics and Global Laccaria phylogenies with collection ID numbers. Notes S2 Specimen information and GenBank sequence IDs. Notes S3 Agaricomycetideae phylogeny and calibration priors for time to MRCA analysis. Notes S4 Agaricomycetideae and Global Laccaria time to MRCA results. Notes S5 BAMM results. Notes S6 BiSSE resu...

•A systematic and evolutionary ecology study of the model ectomycorrhizal (ECM) genus Laccaria was performed using herbarium material and field collections from over 30 countries covering its known geographic range. •A four-gene (nrITS, 28S, RPB2, EF1a) nucleotide sequence dataset consisting of 232 Laccaria specimens was analyzed phylogenetically....

A new species, Amanita glarea, is described and illustrated from Pakistan. Molecular phylogenetic data derived from internal transcribed spacer (ITS) and nuclear ribosomal large subunit (LSU) regions along with morphological characters make it distinct from other currently known Amanita species. Amanita glarea is characterized by a grayish brown, s...

Most conservation efforts in seasonally dry tropical forests have overlooked less obvious targets for conservation, such as mycorrhizal fungi, that are critical to plant growth and ecosystem structure. We documented the diversity of ectomycorrhizal (EMF) and arbuscular mycorrhizal (AMF) fungal communities in Quercus oleoides (Fagaceae) in Guanacast...

Recent molecular systematic studies of Cantharellus cibarius sensu lato have revealed previously unknown species in different regions of North America. This study investigates yellow chanterelles in the Midwest using phylogenetic analysis of three DNA regions: nuc rDNA internal transcribed spacer 2 (ITS2) and 28S sequences and translation elongatio...

We formulate five guidelines for introducing new genera, plus one recommendation how to publish the results of scientific research. We recommend that reviewers and editors adhere to these guidelines. We propose that the underlying research is solid, and that the results and the final solutions are properly discussed. The six criteria are: (1) all g...

The ICP Forests network can be a platform for large-scale mycorrhizal studies. Mapping and monitoring of mycorrhizas have untapped potential to inform science, management, conservation and policy regarding distributions, diversity hotspots, dominance and rarity, and indicators of forest changes. A dearth of information about fungi at large scales...

Given the diversity and ecological importance of Fungi, there is a lack of population genetic research on these organisms. The reason for this can be explained in part by their cryptic nature and difficulty in identifying genets. In addition the difficulty (relative to plants and animals) in developing molecular markers for fungal population geneti...

We test our 'one-log-one-genet' sampling method for the Hawaiian mushroom Rhodocollybia laulaha - that all of the R. laulaha mushrooms collected from a single log represent a single genet. We also examine the potential expansion of single genets beyond the confines of one log and the temporal persistence of genets in nature. Finally, we estimate er...

Craterellus olivaceoluteus sp. nov. and Craterellus cinereofimbriatus sp. nov. are described as new to science. These fungi were collected from Guyana in association with ectomycorrhizal host trees in the genera Dicymbe (Fabaceae subfam. Caesalpinioideae) and Pakaraimaea (Dipterocarpaceae). Cantharellus guyanensis Mont., originally described from F...

Species of Laccaria are described from the eastern Himalayas, in the Xizang Autonomous Region of China, more commonly known as Tibet. Specimens were collected during several expeditions over a 12-year time span. Nuclear ribosomal internally transcribed spacer regions 1 and 2 including and 5.8S (ITS) as well as the 5' end of the large subunit (28S)...

Here we report the first population genetic examination of a fungus in Hawaii and, to our knowledge, the only investigation of a saprotrophic fungal population distributed across an oceanic archipelago. Rhodocollybia laulaha fruits abundantly in the native rain forests of Hawaii from June through December. Its range includes the geographic extent o...

Members of the Cantharellaceae (Cantharellales, Basidiomycota) are common ectomycorrhizal associates of the leguminous genus Dicymbe in the Pakaraima Mountains of Guyana. Currently eight distinct species or morphospecies are recognized in Craterellus Pers. or Cantharellus Adans. ex Fr. from Guyanese Dicymbe-dominated forests. We evaluated the syste...

Amanita conara, A. costaricensis, and A. garabitoana are proposed as new species. These taxa are added to twelve previously described species known from, or reported here for the first time from, the region of study: A. advena, A. arocheae, A. brunneolocularis, A. colombiana, A. ebumea, A. farinosa, A. flavoconia var. inquinata, A. fuligineodisca,...

The evolutionary mechanisms that give rise to microsatellite alleles remain poorly understood in general and are especially understudied for fungal microsatellite loci. The unusual G28 microsatellite locus was developed from the Hawaiian mushroom Rhodocollybia laulaha. Here, we employ a novel approach to test for allele size homoplasy and examine c...

With its strict criteria, required documentation and coverage of all groups of multicellular organisms, the red-listing system of IUCN is recognized as the most authoritative guide to the status of biological diversity. The aim of red-listing sensu IUCN is to evaluate the risk of extinction of a species using a comparable, revisable, transparent an...

Ten new species of Cortinarius are described from Costa Rican neotropical montane forests based on morphological and molecular phylogenetic data. Morphological features of the basidiomes and nuclear rDNA sequence analyses place these species in the following clades: Anomali (Cortinarius sericeolazulinus), Cotoneus (Cortinarius aureopigmentatus), Li...

We tested the nuclear ribosomal intergenic spacer 1 (IGS1) to evaluate: 1) the utility of this gene region in the study of intra-lineage variation in the Hawaiian mushroom Rhodocollybia laulaha (Basidiomycota, Marasmiaceae); 2) the possibility of PCR-mediated artifacts from multiple cloned IGS1 inserts for five of the nine specimens included; and 3...

The Hawaiian mushroom Rhodocollybia laulaha was selected as a model to investigate patterns of gene flow between geographically isolated fungal populations from ecologically and bioclimatically varied sites. Its morphology (distinctive when compared to other members of the genus) and affinity for endemic Hawaiian forest suggested that it was endemi...

We tested the accuracy of molecular analyses for recovering the species richness and structure of pooled fungal communities of known composition. We constructed replicate pools of 2-20 species and analysed these pools by two separate pooling-DNA extraction procedures and three different molecular analyses (Automated Ribosomal Intergenic Spacer Anal...

How nitrogen (N) deposition impacts ectomycorrhizal (EM) fungal communities has been little studied in deciduous forests or across spatial scales. Here, it was tested whether N addition decreases species richness and shifts species composition across spatial scales in temperate deciduous oak forests. Combined molecular (terminal restriction fragmen...

The rigorous study of processes shaping geographic distributions of lineages is a relatively new and emerging field in mycology. While it was previously generally believed that most fungi have wide distributions and largely unstructured populations, recent studies have shown that this is not the case. The study of distributions in tandem with molec...

GenBank, the public repository for nucleotide and protein sequences, is a critical resource for molecular biology, evolutionary biology, and ecology. While some attention has been drawn to sequence errors ([1][1]), common annotation errors also reduce the value of this database. In fact, for

Ten taxa of Laccaria are recognized from Sweden: L. amethystina, L. bicolor, L. laccata var. laccala, L. laccala var. moelleri, L. laccata var. pallidifolia, L. maritima, L. montana, L. proximo, L. pumila, and L. tortilis. A key to treated taxa, descriptions of macro- and micromorphology of these taxa and a discussion of their distribution in north...

Data on macrofungal diversity and distribution patterns were compiled for major geographical regions of the world. Macrofungi are defined here to include ascomycetes and basidiomycetes with large, easily observed spore-bearing structures that form above or below ground. Each coauthor either provided data on a particular taxonomic group of macrofung...

We conservatively estimate that there is a minimum of 712,000 extant fungal species worldwide, but we recognize that the actual species richness is likely much higher. This estimate was calculated from the ratio of fungal species to plant species for various ecologically defined groups of fungi in well-studied regions, along with data on each group...

Although fungi are among the most important organisms in the world, only limited and incomplete information is currently available for most species and current estimates of species numbers for fungi differ significantly. This lack of basic information on taxonomic diversity has significant implications for many aspects of evolutionary biology. Whil...

Terminal restriction fragment length polymorphism (TRFLP) is an increasingly popular method in molecular ecology. However, several key limitations of this method have not been fully examined especially when used to study fungi. We investigated the impact of spore contamination, intracollection ribosomal DNA internal transcribed spacer (ITS) region...

Pairs of taxa are commonly found in lichen-forming ascomycetes that differ primarily in their reproductive modes: one taxon reproduces sexually, the other vegetatively. The evolutionary processes underlying such "species pairs" are unknown. The species pair formed by Porpidia flavocoerulescens (sexual) and Porpidia melinodes (vegetative) was chosen...

In 1996, a coalition of diverse and determined organizations launched a new initiative in the Chicago region. Our vision? Chicago Wilderness: a thriving mosaic of natural areas, connected by greenways and wildlife corridors, embedded in the nation's third largest metropolis. In this vision, the region's human communities reclaim a cultural traditio...

The alpine zone is comprised of habitats at elevations above treeline, and macromycetes play important ecological roles as decomposers and mycorrhizal symbionts here as elsewhere. Laccaria is an important group of ectomycorrhizal basidiomycetes widely used in experimental and applied research. A systematic study of alpine Laccaria species using mor...

The alpine zone is comprised of habitats at elevations above treeline, and macromycetes play important ecological roles as decomposers and mycorrhizal symbionts here as elsewhere. Laccaria is an important group of ectomycorrhizal basidiomycetes widely used in experimental and applied research. A systematic study of alpine Laccaria species using mor...

The phylogenetic relationships of many lichen-forming perithecioid ascomycetes are unknown. We generated nuLSU and mtSSU rDNA sequences of members of seven families of pyrenocarpous lichens and used a Bayesian framework to infer a phylogenetic estimate. Members of the perithecioid Protothelenellaceae, Thelenellaceae and Thrombiaceae surprisingly cl...

Attempts to understand and conserve biodiversity are hampered by a lack of information about many taxonomic groups, particularly those groups that are the most species rich. Although fungi are ubiquitous and play an important role in decomposition, nutrient cycling and nutrient uptake, little is known about fungal diversity, as fungi are usually cr...

The phylogenetic relationships of many lichen-forming perithecioid ascomycetes are unknown. We generated nuLSU and mtSSU rDNA sequences of members of seven families of pyrenocarpous lichens and used a Bayesian framework to infer a phylogenetic estimate. Members of the perithecioid Protothelenellaceae, Thelenellaceae and Thrombiaceae surprisingly cl...

The lichen-forming genus Porpidia (Porpidiaceae, Ascomycota) provides excellent opportunities for evolutionary, reproductive, and ecological studies of crustose epilithic lichen symbioses. However, despite the fact that the genus itself seemed to be clearly delimited, the group was thought to be a hopeless case with regard to intrageneric relations...

Biodiversity of Fungi is essential for anyone collecting and/or monitoring any fungi. Fascinating and beautiful, fungi are vital components of nearly all ecosystems and impact human health and our economy in a myriad of ways. Standardized methods for documenting diversity and distribution have been lacking. A wealth of information, especially regra...

Biodiversity of Fungi is essential for anyone collecting and/or monitoring any fungi. Fascinating and beautiful, fungi are vital components of nearly all ecosystems and impact human health and our economy in a myriad of ways. Standardized methods for documenting diversity and distribution have been lacking. A wealth of information, especially regra...

The traditional classification of Gymnopilus (Agaricales) recognizes two primary groups, Annulati and Gymnopilus, based on the presence or absence of a membranous partial veil. While our analyses of DNA sequence data from the nuclear ribosomal ITS1–5.8S-ITS2 (ITS) gene supports the monophyly of the genus, these traditional subgroups were not recove...

The traditional classification of Gymnopilus (Agaricales) recognizes two primary groups, Annulati and Gymnopilus, based on the presence or absence of a membranous partial veil. While our analyses of DNA sequence data from the nuclear ribosomal ITS1-5.8S-ITS2 (ITS) gene supports the monophyly of the genus, these traditional subgroups were not recove...