Dennis E. Desjardin

Global diversity and distribution of macrofungi

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 macrofungi or information on the macrofungi of a specific geographic area. We then employed a meta-analysis to investigate species overlaps between areas, levels of endemism, centers of diversity, and estimated percent of species known for each taxonomic group for each geographic area and for the combined macrofungal data set. Thus, the study provides both a meta-analysis of current data and a gap assessment to help identify research needs. In all, 21,679 names of macrofungi were compiled. The percentage of unique names for each region ranged from 37% for temperate Asia to 72% for Australasia. Approximately 35,000 macrofungal species were estimated to be “unknown” by the contributing authors. This would give an estimated total of 56,679 macrofungi. Our compiled species list does not include data from most of S.E. Europe, Africa, western Asia, or tropical eastern Asia. Even so, combining our list of names with the estimates from contributing authors is in line with our calculated estimate of between 53,000 and 110,000 macrofungal species derived using plant/macrofungal species ratio data. The estimates developed in this study are consistent with a hypothesis of high overall fungal species diversity.

Fungi bioluminescence revisited

A review of the research conducted during the past 30 years on the distribution, taxonomy, phylogeny, ecology, physiology and bioluminescence mechanisms of luminescent fungi is presented. We recognize 64 species of bioluminescent fungi belonging to at least three distinct evolutionary lineages, termed Omphalotus, Armillaria and mycenoid. An accounting of their currently accepted names, distributions, citations reporting luminescence and whether their mycelium and/or basidiomes emit light are provided. We address the physiological and ecological aspects of fungal bioluminescence and provide data on the mechanisms responsible for bioluminescence in the fungi.

Major clades in tropical Agaricus

Agaricus (Basidiomycota) is a genus of saprobic fungi that includes edible cultivated species such as Agaricus bisporus, the button mushroom. There has been considerable ecological, nutritional and medicinal interest in the genus, yet the extent of its diversity remains poorly known, particularly in subtropical and tropical areas. Classification of tropical species has for a large part followed the classification of temperate species. The objective of our study was to examine to what extent this system of classification is appropriate for tropical Agaricus species. Species from temperate sections were therefore compared to the major clades of tropical species using a phylogenetic approach. ITS1 + 2 sequence data from 128 species were used in the phylogenetic analysis. Specimens included four species of genera closely related to Agaricus, 38 temperate species representing the eight classical sections of the genus, and 86 putative species of Agaricus from tropical areas of Africa, Asia and the Americas. Bayesian and maximum likelihood analyses produced relatively congruent trees and almost identical clades. Our data show that (i) only about one-third of tropical species belong to the classical sections based on temperate species; the systematics of the genus therefore needs to be expanded; (ii) among the remaining two-thirds of tropical species, those from the Americas and those from Africa and/or Asia group in distinct clades, suggesting that secondary diversification occurred in these two areas; (iii) in contrast, several clades of classical sections contain American and African + Asian species along with temperate species. In this study, we used approximately 50 distinct species from a small area of northern Thailand, most probably being novel species. This diversity indicates that Agaricus is a species-rich genus in the tropics as well as in temperate regions. The number of species and the hypothetical paleotropical origin of the genus are discussed.

Molecular phylogeny, morphology, pigment chemistry and ecology in Hygrophoraceae (Agaricales)

Molecular phylogenies using 1–4 gene regions and information on ecology, morphology and pigment chemistry were used in a partial revision of the agaric family Hygro- phoraceae. The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are: Acantholichen, Ampulloclitocybe, Arrhenia, Cantharellula, Cantharocybe, Chromosera, Chrysomphalina, Cora, Corella, Cuphophyllus, Cyphellostereum, Dictyonema, Eonema, Gliophorus, Haasiella, Humidicutis, Hygroaster, Hygrocybe, Hygrophorus, Lichenomphalia, Neohygrocybe, Porpolomopsis and Pseudoarmillariella. A new genus that is sister to Chromosera is described as Gloioxanthomyces. Revisions were made at the ranks of subfamily, tribe, genus, subgenus, section and subsection. We present three new subfamilies, eight tribes (five new), eight subgenera (one new, one new combination and one stat. nov.), 26 sections (five new and three new combinations and two stat. nov.) and 14 subsections (two new, two stat. nov.). Species of Chromosera, Gliophorus, Humidicutis, and Neohygrocybe are often treated within the genus Hygrocybe; we therefore provide valid names in both classification systems. We used a minimalist approach in transferring genera and creating new names and combinations. Consequently, we retain in the Hygrophoraceae the basal cuphophylloid grade comprising the genera Cuphophyllus, Ampulloclitocybe and Cantharocybe, despite weak phylogenetic support. We include Aeruginospora and Semiomphalina in Hygrophoraceae based on morphology though molecular data are lacking. The lower hygrophoroid clade is basal to Hygrophoraceae s.s., comprising the genera Aphroditeola, Macrotyphula, Phyllotopsis, Pleurocybella, Sarcomyxa, Tricholomopsis and Typhula.

Evidence that a single bioluminescent system is shared by all known bioluminescent fungal lineages

Since the early 20th century, many researchers have attempted to determine how fungi are able to emit light. The first successful experiment was obtained using the classical luciferin-luciferase test that consists of mixing under controlled conditions hot (substrate/luciferin) and cold (enzyme/luciferase) water extracts prepared from bioluminescent fungi. Failures by other researchers to reproduce those experiments using different species of fungi lead to the hypothesis of a non-enzymatic luminescent pathway. Only recently, the involvement of a luciferase in this system was proven, thus confirming its enzymatic nature. Of the 100,000 described species in Kingdom Fungi, only 71 species are known to be luminescent and they are distributed unevenly amongst four distantly related lineages. The question we address is whether the mechanism of bioluminescence is the same in all four evolutionary lineages suggesting a single origin of luminescence in the Fungi, or whether each lineage has a unique mechanism for light emission implying independent origins. We prepared hot and cold extracts of numerous species representing the four bioluminescent fungal lineages and performed cross-reactions (luciferin × luciferase) in all possible combinations using closely related non-luminescent species as controls. All cross-reactions with extracts from luminescent species yielded positive results, independent of lineage, whereas no light was emitted in cross-reactions with extracts from non-luminescent species. These results support the hypothesis that all four lineages of luminescent fungi share the same type of luciferin and luciferase, that there is a single luminescent mechanism in the Fungi, and that fungal luciferin is not a ubiquitous molecule in fungal metabolism.

A unique ballistosporic hypogeous sequestrate Lactarius from California

Lactarius rubriviridis sp. nov., characterized by hypogeous, sequestrate basidiomes with red latex, green stains, and forcibly discharged, reticulate basidiospores is described and illustrated. During the Spring, the new species forms basidiomes associated with conifers at 1400–1800 m elevation in the Sierra Nevada, and is known from two specimens collected 19 yr apart. Comparisons with the putatively polyphyletic genera Arcangeliella and Zelleromyces, and an accounting of all known members of these genera are provided.

Durianella, a new gasteroid genus of boletes from Malaysia

Hydnangium echinulatum, described originally from a single specimen collected in Malaysia, has been recollected, and based on morphological and molecular characters is recognized as representing a new gasteroid genus of boletes with affinities to the Boletineae, herein named Durianella. Diagnostic features include an epigeous, ovoid, pyramidal-warted, durian fruit-like basidiome with gelatinized glebal locules and a columella that turns indigo blue upon exposure, and subglobose basidiospores with long, curved, thin-walled and collapsible spines. A redescription, phylogenetic analysis and comparison with allied taxa are presented.

Luminescent Mycena: new and noteworthy species

Seven species of Mycena are reported as luminescent, representing specimens collected in Belize, Brazil, Dominican Republic, Jamaica, Japan (Bonin Islands), Malaysia (Borneo) and Puerto Rico. Four of them represent new species (Mycena luxaeterna, M. luxarboricola, M. luxperpetua, M. silvaelucens) and three represent new reports of luminescence in previously described species (M. aff. abieticola, M. aspratilis, M. margarita). Mycena subepipterygia is synonymized with M. margarita, and M. chlorinosma is proposed as a possible synonym. Comprehensive descriptions, illustrations, photographs and comparisons with phenetically similar species are provided. A redescription of M. chlorophos, based on analyses of type specimens and recently collected topotypical material, is provided. The addition of these seven new or newly reported luminescent species of Mycena brings the total to 71 known bioluminescent species of fungi.

A monograph of Micropsalliota in Northern Thailand based on morphological and molecular data

Using a combination of morphological and molecular data, the genus Micropsalliota is shown to represent a monophyletic lineage in the Agaricaceae sister to Hymenagaricus. Features that distinguish the genus from Agaricus and allied genera include usually small, gracile basidiomes with a membranous partial veil, dextrinoid basidiospores with an apically thickened endosporium and lack of a germ pore, capitate or subcapitate, conspicuous cheilocystidia, and incrusted pileipellis hyphae that turn green in ammonia solution. We provide a monographic treatment of 23 taxa of Micropsalliota from Northern Thailand, of which 13 taxa represent new distribution reports for Thailand and 10 represent new taxa, including M. allantoidea, M. bifida, M. furfuracea, M. lateritia var. vinaceipes, M. megarubescens, M. megaspora, M. pusillissima, M. rubrobrunnescens var. rubrobrunnescens, M. rubrobrunnescens var. tibiicystis, and M. suthepensis. Included in this monograph are comprehensive descriptions, illustrations of micromorphological features, photographs of basidiomes, comparisons with allied species, phylogenetic trees inferring relationships amongst Thai species based on nrITS and nrLSU sequence datasets, and a key to aid in diagnosis.

Bioluminescent Mycena species from São Paulo, Brazil

Six species of bioluminescent agarics are described and illustrated from a single site in primary Atlantic Forest habitat in the Parque Estadual Turístico do Alto Ribeira, São Paulo State, Brazil. These include two new taxa of Mycena, viz. M. asterina and M. lucentipes. Luminescence in Mycena fera, M. singeri and M. discobasis is reported for the first time. In addition an undeterminable luminescent Mycena species is described and additional specimens of Gerronema viridilucens are documented. An accounting of known bioluminescent species of Mycena and a discussion of why they luminesce are presented.