David W. Minter

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.

Molecular phylogeny reveals a core clade of Rhytismatales

Rhytismatales (Leotiomycetes, Pezizomycotina, Ascomycota) are an order of mostly plant-associated ascomycetes with a global distribution. Well known taxa include the Rhytisma tar spots on Acer spp. and several needle-cast pathogens in genera Lophodermium and Meloderma. Critical studies are lacking at all taxonomic ranks from order to species, and in particular the genus taxonomy in the order has been criticized for being unnatural. We used nuclear LSU and mitochondrial SSU sequences in Bayesian phylogenetic analyses to define a core clade of Rhytismatales sensu stricto. Some of the genera traditionally placed within the Rhytismatales, Ascodichaena, Marthamyces, Mellitiosporium, Potebniamyces, Propolis and Pseudophacidium, are shown to be phylogenetically distinct, all related to various other taxa at present placed in the polyphyletic Helotiales. Within the core clade only Cudonia, Spathularia and Terriera are supported as monophyletic. The large genera Coccomyces, Hypoderma and Lophodermium all are polyphyletic as are a few smaller genera. The traditionally used characters of ascoma and spore shape are shown to be unreliable for the delimitation of monophyletic genera but in some cases can be useful when combined with other characters. In this study we provide 72 new nrLSU and 64 new mtSSU sequences. Together withPUBLICly available sequences data for 103 specimens representing 91 species of Rhytismatales are now available. Despite this taxon sampling intensity is still too low to propose an alternative generic taxonomy.

Fluorescence microscopy: An aid to the elucidation of ascomycete structures

Freshly collected specimens and preserved herbarium material of ascomycetes from a variety of orders were dissected to obtain slide preparations of ascogenous cells, paraphyses, asci and ascospores. Phase contrast, differential interference contrast and fluorescent light microscopy were used to examine each species in a range of mountants including water, erythrosin, Melzers reagent, lactophenol and calcofluor. Detailed results are provided for Diatrype disciformis, Hypoxylon fuscum, Peltigera horizontalis and Pleurostoma ootheca . Asci of Diatrype disciformis were found to have more than one functional wall layer, and its ascogenous cells are described and illustrated for the first time. Hitherto unknown fluorescent rings are described in asci and ascospores of Hypoxylon fuscum . In Peltigera horizontalis fluorescent light microscopy confirms an earlier TEM study of ascus structure and dehiscence in the genus, and asci of Pleurostoma ootheca are described as having lateral thickening, a strongly fluorescing base and a mode of secession from their ascogenous cells apparently previously unknown in the ascomycetes. Most of these features could not be seen at all, or only with difficulty without fluorescent light. Each appeared similar in fresh collections and herbarium specimens dried and preserved for up to one hundred years. Fluorescent light microscopy can provide new information of great value to students of the ascomycetes.

Structure and taxonomic significance of the ascus in the coryneliaceae

Asci of most members of the Coryneliaceae were examined. All species of Corynelia, Coryneliospora Fitzpatrickiella, Lagenulopsis , and Tripospora , and representative species of Caliciopsis and Coryneliopsis were studied by light microscopy. Two species of Corynelia were also examined using transmission electron microscopy. Except in Coryneliopsis , all had asci with more than one functional wall layer with the outer layer breaking during ascus elongation, long before ascospores are ready to be released. It is concluded that the order Coryneliales, containing the single family Coryneliaceae, should be retained, and that Coryneliopsis should probably be removed from the family.

Gymnohydnotrya: a new hypogeous ascomycete genus from Australia

Gymnohydnotrya gen. nov. (Ascomycotina, Pezizales, Helvellaceae) typified by G. australiana sp. nov. and containing G. echinulata (Beaton) comb. nov. and G. ellipsospora (Cribb) comb. nov. is described, illustrated and discussed with a key to the three species. Ascospores of G. australiana each contain four nuclei and bear a previously undescribed type of ornamentation. The taxonomic significance of these features is discussed.

Factors shaping communities of pyrophilous macrofungi in microhabitats destroyed by illegal campfires

Pyrophilous macrofungi (PM) are a narrowly specialised group appearing exclusively in plant communities recently destroyed by fire. Their significance has hitherto been studied only for vegetation destroyed over large areas, while in small areas of fire, i.e., microhabitats they are viewed as independent components of the community linked only to the substratum. In the present work, the following hypotheses were tested: (1) species structures of PM in microhabitats depend on the type of plant community, (2) PM form communities on a small scale which are similar in structure and function to analogous large scale communities. We studied 20 surfaces destroyed by illegal campfires in four natural plant communities: oak-hornbeam forest Tilio-Carpinetum (TC), lowland acidophilus beech forest Luzulo pilosae-Fagetum (LF), suboceanic pine forest Leucobryo-Pinetum (LP), and an initial-phase xerothermic grassland community on a transitional habitat (MH). TC and LF habitats were conspicuously more favourable for PM than LP and MH. In TC and LF fire leads to significant loss of mycorrhizae in the upper layer of leaf litter. This provides a development opportunity for ectomycorrhizal PM species which, having little competition, substitute for the destroyed fragments of mycorrhizal networks. In LP and MH fire over a small surface does not destroy more deeply located mycorrhizal associations. Another important factor for PM influencing the quality of environment is the fertility of soil: highest in TC, intermediate in LF and lowest in LP and MH. The results casts doubt on the concept that PM are only synusia linked to the substratum (burnt wood). PM growing in microhabitats constitute an important group of organisms which facilitate rapid regeneration of plant community fragments destroyed by fire.

Morphology, cytology and taxonomy of Choiromyces gangliiformis (Ascomycotina, Pezizales).

A recent collection of Choiromyces gangliiformis is described and illustrated. The asci have multi-layered walls clearly visible with the light microscope. Scanning electron microscopy revealed that the ascospores are ornamented with minute hemispherical pits. Ascospore nuclei were studied with HCl-Giemsa staining and each ascospore was found to contain four nuclei. The systematic position of the genus and the significance of ascospore nuclear numbers in the phylogeny of the Pezizales are discussed in the light of these discoveries.

A new species of Lophodermium on needles of mountain pine ( Pinus mugo ) from the Giant Mountains in Poland

A fungus tentatively identified as Lophodermium sp. was repeatedly isolated from living secondary needles of mountain pine (Pinus mugo) in the Giant Mountains of Poland. Needles showed symptoms of yellow spots, gradual discolouration and premature falling in July. Thin black zone lines, subepidermal conidiomata and partially subepidermal ascomata morphologically similar to L. pinastri occurred on fallen needles in litter below the same trees. Evidence from internal transcribed spacers of rDNA and the gene for actin showed that strains isolated from symptom-bearing needles and fruiting structures were identical, and differed from other Lophodermium species known from pine, including L. pinastri. The fungus differs subtly from L. pinastri, for example, in the lengths of its conidiomata, ascomata and asci, but can be reliably distinguished only by molecular data. Known only on mountain pine from the Giant Mountains, it is described here as L. corconticum sp. nov.

New species of Lobatopedis and Minimelanolocus (anamorphic fungi) from a Mexican cloud forest

Abstract : Two new species in the genera Lobatopedis and Minimelanolocus were found during an investigation of anamorphic fungi from plant debris collected in a cloud forest in Veracruz State, Mexico. Both are described and illustrated. Lobatopedis kirkii sp. nov. is characterized by brown, macronematous conidiophores, monoblastic conidiogenous cells, and brown, cylindrical, narrowly obclavate to sub-acicular conidia which differ from those of other species of Lobatopedis in shape. Minimelanolocus limpidus sp. nov. is characterized by macronematous dark brown conidiophores, polyblastic conidiogenous cells with slightly melanized scars, and obclavate, (3–)6-septate, pale golden brown conidia. A comparative table and a key to Lobatopedis species are also provided. Key words : hyphomycetes, microfungi, nature conservation, taxonomy. Introduction Cloud forests (CF) are among the most diverse biomes in the world. In Mexico, this kind of forest, although covering less than 1% of the land surface, contains 10–12% of the country’s flowering plant species (Rzedowski 1996). Because of the climatological characteristics, all kinds of fungi grow in the wide variety of habitats provided by these forests. Unfortunately, CF are severely threatened not only in Mexico but also worldwide. Urgent exploration of the few remnants of such forests is therefore needed. As part of a long-term study of anamorphic fungi from cloud forests, multiple

A new species of Ceratocladium from Spain

The anamorphic fungus Ceratocladium polysetosum sp. nov., found on unidentified dead wood in the National Park of Ordesa y Monte Perdido, Spain, is described and illustrated. This fungus is characterized by the presence of unbranched primary setae and secondary setae originating from climbing fertile hyphae on the primary setae and by production of cylindrical or fusiform conidia. Circinotrichum pseudocladum is transferred to Ceratocladium based on the presence of fertile and ascending hyphae growing on the setae. A key to the accepted Ceratocladium species is provided.