This paper is a compilation of notes on 142 fungal taxa, including five new families, 20 new genera, and 100 new species, representing a wide taxonomic and geographic range. The new families, Ascocylindricaceae, Caryosporaceae and Wicklowiaceae (Ascomycota) are introduced based on their distinct lineages and unique morphology. The new Dothideomycete genera Pseudomassariosphaeria (Amniculicolaceae), Heracleicola, Neodidymella and Pseudomicrosphaeriopsis (Didymellaceae), Pseudopithomyces (Didymosphaeriaceae), Brunneoclavispora, Neolophiostoma and Sulcosporium (Halotthiaceae), Lophiohelichrysum (Lophiostomataceae), Galliicola, Populocrescentia and Vagicola (Phaeosphaeriaceae), Ascocylindrica (Ascocylindricaceae), Elongatopedicellata (Roussoellaceae), Pseudoasteromassaria (Latoruaceae) and Pseudomonodictys (Macrodiplodiopsidaceae) are introduced. The newly described species of Dothideomycetes (Ascomycota) are Pseudomassariosphaeria bromicola (Amniculicolaceae), Flammeascoma lignicola (Anteagloniaceae), Ascocylindrica marina (Ascocylindricaceae), Lembosia xyliae (Asterinaceae), Diplodia crataegicola and Diplodia galiicola (Botryosphaeriaceae), Caryospora aquatica (Caryosporaceae), Heracleicola premilcurensis and Neodidymella thailandicum (Didymellaceae), Pseudopithomyces palmicola (Didymosphaeriaceae), Floricola viticola (Floricolaceae), Brunneoclavispora bambusae, Neolophiostoma pigmentatum and Sulcosporium thailandica (Halotthiaceae), Pseudoasteromassaria fagi (Latoruaceae), Keissleriella dactylidicola (Lentitheciaceae), Lophiohelichrysum helichrysi (Lophiostomataceae), Aquasubmersa japonica (Lophiotremataceae), Pseudomonodictys tectonae (Macrodiplodiopsidaceae), Microthyrium buxicola and Tumidispora shoreae (Microthyriaceae), Alloleptosphaeria clematidis, Allophaeosphaeria cytisi, Allophaeosphaeria subcylindrospora, Dematiopleospora luzulae, Entodesmium artemisiae, Galiicola pseudophaeosphaeria, Loratospora luzulae, Nodulosphaeria senecionis, Ophiosphaerella aquaticus, Populocrescentia forlicesenensis and Vagicola vagans (Phaeosphaeriaceae), Elongatopedicellata lignicola, Roussoella magnatum and Roussoella angustior (Roussoellaceae) and Shrungabeeja longiappendiculata (Tetraploasphaeriaceae). The new combinations Pseudomassariosphaeria grandispora, Austropleospora archidendri, Pseudopithomyces chartarum, Pseudopithomyces maydicus, Pseudopithomyces sacchari, Vagicola vagans, Punctulariopsis cremeoalbida and Punctulariopsis efibulata Dothideomycetes. The new genera Dictyosporella (Annulatascaceae), and Tinhaudeus (Halosphaeriaceae) are introduced in Sordariomycetes (Ascomycota) while Dictyosporella aquatica (Annulatascaceae), Chaetosphaeria rivularia (Chaetosphaeriaceae), Beauveria gryllotalpidicola and Beauveria loeiensis (Cordycipitaceae), Seimatosporium sorbi and Seimatosporium pseudorosarum (Discosiaceae), Colletotrichum aciculare, Colletotrichum fusiforme and Colletotrichum hymenocallidicola (Glomerellaceae), Tinhaudeus formosanus (Halosphaeriaceae), Pestalotiopsis subshorea and Pestalotiopsis dracaenea (Pestalotiopsiceae), Phaeoacremonium tectonae (Togniniaceae), Cytospora parasitica and Cytospora tanaitica (Valsaceae), Annulohypoxylon palmicola, Biscogniauxia effusae and Nemania fusoideis (Xylariaceae) are introduced as novel species to order Sordariomycetes. The newly described species of Eurotiomycetes are Mycocalicium hyaloparvicellulum (Mycocaliciaceae). Acarospora septentrionalis and Acarospora castaneocarpa (Acarosporaceae), Chapsa multicarpa and Fissurina carassensis (Graphidaceae), Sticta fuscotomentosa and Sticta subfilicinella (Lobariaceae) are newly introduced in class Lecanoromycetes. In class Pezizomycetes, Helvella pseudolacunosa and Helvella rugosa (Helvellaceae) are introduced as new species. The new families, Dendrominiaceae and Neoantrodiellaceae (Basidiomycota) are introduced together with a new genus Neoantrodiella (Neoantrodiellaceae), here based on both morphology coupled with molecular data. In the class Agaricomycetes, Agaricus pseudolangei, Agaricus haematinus, Agaricus atrodiscus and Agaricus exilissimus (Agaricaceae), Amanita melleialba, Amanita pseudosychnopyramis and Amanita subparvipantherina (Amanitaceae), Entoloma calabrum, Cora barbulata, Dictyonema gomezianum and Inocybe granulosa (Inocybaceae), Xerocomellus sarnarii (Boletaceae), Cantharellus eucalyptorum, Cantharellus nigrescens, Cantharellus tricolor and Cantharellus variabilicolor (Cantharellaceae), Cortinarius alboamarescens, Cortinarius brunneoalbus, Cortinarius ochroamarus, Cortinarius putorius and Cortinarius seidlii (Cortinariaceae), Hymenochaete micropora and Hymenochaete subporioides (Hymenochaetaceae), Xylodon ramicida (Schizoporaceae), Colospora andalasii (Polyporaceae), Russula guangxiensis and Russula hakkae (Russulaceae), Tremella dirinariae, Tremella graphidis and Tremella pyrenulae (Tremellaceae) are introduced. Four new combinations Neoantrodiella gypsea, Neoantrodiella thujae (Neoantrodiellaceae), Punctulariopsis cremeoalbida, Punctulariopsis efibulata (Punctulariaceae) are also introduced here for the division Basidiomycota. Furthermore Absidia caatinguensis, Absidia koreana and Gongronella koreana (Cunninghamellaceae), Mortierella pisiformis and Mortierella formosana (Mortierellaceae) are newly introduced in the Zygomycota, while Neocallimastix cameroonii and Piromyces irregularis (Neocallimastigaceae) are introduced in the Neocallimastigomycota. Reference specimens or changes in classification and notes are provided for Alternaria ethzedia, Cucurbitaria ephedricola, Austropleospora, Austropleospora archidendri, Byssosphaeria rhodomphala, Lophiostoma caulium, Pseudopithomyces maydicus, Massariosphaeria, Neomassariosphaeria and Pestalotiopsis montellica.

This paper is a compilation of notes on 110 fungal taxa, including one new family, 10 new genera, and 76 new species, representing a wide taxonomic and geographic range. The new family, Paradictyoarthriniaceae is introduced based on its distinct lineage in Dothideomycetes and its unique morphology. The family is sister to Biatriosporaceae and Roussoellaceae. The new genera are Allophaeosphaeria (Phaeosphaeriaceae), Amphibambusa (Amphisphaeriaceae), Brunneomycosphaerella (Capnodiales genera incertae cedis), Chaetocapnodium (Capnodiaceae), Flammeascoma (Anteagloniaceae), Multiseptospora (Pleosporales genera incertae cedis), Neogaeumannomyces (Magnaporthaceae), Palmiascoma (Bambusicolaceae), Paralecia (Squamarinaceae) and Sarimanas (Melanommataceae). The newly described species are the Ascomycota Aliquandostipite manochii, Allophaeosphaeria dactylidis, A. muriformia, Alternaria cesenica, Amphibambusa bambusicola, Amphisphaeria sorbi, Annulohypoxylon thailandicum, Atrotorquata spartii, Brunneomycosphaerella laburni, Byssosphaeria musae, Camarosporium aborescentis, C. aureum, C. frutexensis, Chaetocapnodium siamensis, Chaetothyrium agathis, Colletotrichum sedi, Conicomyces pseudotransvaalensis, Cytospora berberidis, C. sibiraeae, Diaporthe thunbergiicola, Diatrype palmicola, Dictyosporium aquaticum, D. meiosporum, D. thailandicum, Didymella cirsii, Dinemasporium nelloi, Flammeascoma bambusae, Kalmusia italica, K. spartii, Keissleriella sparticola, Lauriomyces synnematicus, Leptosphaeria ebuli, Lophiostoma pseudodictyosporium, L. ravennicum, Lophiotrema eburnoides, Montagnula graminicola, Multiseptospora thailandica, Myrothecium macrosporum, Natantispora unipolaris, Neogaeumannomyces bambusicola, Neosetophoma clematidis, N. italica, Oxydothis atypica, Palmiascoma gregariascomum, Paraconiothyrium nelloi, P. thysanolaenae, Paradictyoarthrinium tectonicola, Paralecia pratorum, Paraphaeosphaeria spartii, Pestalotiopsis digitalis, P. dracontomelon, P. italiana, Phaeoisaria pseudoclematidis, Phragmocapnias philippinensis, Pseudocamarosporium cotinae, Pseudocercospora tamarindi, Pseudotrichia rubriostiolata, P. thailandica, Psiloglonium multiseptatum, Saagaromyces mangrovei, Sarimanas pseudofluviatile, S. shirakamiense, Tothia spartii, Trichomerium siamensis, Wojnowicia dactylidicola, W. dactylidis and W. lonicerae. The Basidiomycota Agaricus flavicentrus, A. hanthanaensis, A. parvibicolor, A. sodalis, Cantharellus luteostipitatus, Lactarius atrobrunneus, L. politus, Phylloporia dependens and Russula cortinarioides are also introduced. Epitypifications or reference specimens are designated for Hapalocystis berkeleyi, Meliola tamarindi, Pallidocercospora acaciigena, Phaeosphaeria musae, Plenodomus agnitus, Psiloglonium colihuae, P. sasicola and Zasmidium musae while notes and/or new sequence data are provided for Annulohypoxylon leptascum, A. nitens, A. stygium, Biscogniauxia marginata, Fasciatispora nypae, Hypoxylon fendleri, H. monticulosum, Leptosphaeria doliolum, Microsphaeropsis olivacea, Neomicrothyrium, Paraleptosphaeria nitschkei, Phoma medicaginis and Saccotheciaceae. A full description of each species is provided with light micrographs (or drawings). Molecular data is provided for 90 taxa and used to generate phylogenetic trees to establish a natural classification for species.

This article is the tenth series of the Fungal Diversity Notes, where 114 taxa distributed in three phyla, ten classes, 30 orders and 53 families are described and illustrated. Taxa described in the present study include one new family (viz. Pseudoberkleasmiaceae in Dothideomycetes), five new genera (Caatingomyces, Cryptoschizotrema, Neoacladium, Paramassaria and Trochilispora) and 71 new species, (viz. Acrogenospora thailandica, Amniculicola aquatica, A. guttulata, Angustimassarina sylvatica, Blackwellomyces lateris, Boubovia gelatinosa, Buellia viridula, Caatingomyces brasiliensis, Calophoma humuli, Camarosporidiella mori, Canalisporium dehongense, Cantharellus brunneopallidus, C. griseotinctus, Castanediella meliponae, Coprinopsis psammophila, Cordyceps succavus, Cortinarius minusculus, C. subscotoides, Diaporthe italiana, D. rumicicola, Diatrypella delonicis, Dictyocheirospora aquadulcis, D. taiwanense, Digitodesmium chiangmaiense, Distoseptispora dehongensis, D. palmarum, Dothiorella styphnolobii, Ellisembia aurea, Falciformispora aquatic, Fomitiporia carpinea, F. lagerstroemiae, Grammothele aurantiaca, G. micropora, Hermatomyces bauhiniae, Jahnula queenslandica, Kamalomyces mangrovei, Lecidella yunnanensis, Micarea squamulosa, Muriphaeosphaeria angustifoliae, Neoacladium indicum, Neodidymelliopsis sambuci, Neosetophoma miscanthi, N. salicis, Nodulosphaeria aquilegiae, N. thalictri, Paramassaria samaneae, Penicillium circulare, P. geumsanense, P. mali-pumilae, P. psychrotrophicum, P. wandoense, Phaeoisaria siamensis, Phaeopoacea asparagicola, Phaeosphaeria penniseti, Plectocarpon galapagoense, Porina sorediata, Pseudoberkleasmium chiangmaiense, Pyrenochaetopsis sinensis, Rhizophydium koreanum, Russula prasina, Sporoschisma chiangraiense, Stigmatomyces chamaemyiae, S. cocksii, S. papei, S. tschirnhausii, S. vikhrevii, Thysanorea uniseptata, Torula breviconidiophora, T. polyseptata, Trochilispora schefflerae and Vaginatispora palmae). Further, twelve new combinations (viz. Cryptoschizotrema cryptotrema, Prolixandromyces australi, P. elongatus, P. falcatus, P. longispinae, P. microveliae, P. neoalardi, P. polhemorum, P. protuberans, P. pseudoveliae, P. tenuistipitis and P. umbonatus), an epitype is chosen for Cantharellus goossensiae, a reference specimen for Acrogenospora sphaerocephala and new synonym Prolixandromyces are designated. Twenty-four new records on new hosts and new geographical distributions are also reported (i.e. Acrostalagmus annulatus, Cantharellus goossensiae, Coprinopsis villosa, Dothiorella plurivora, Dothiorella rhamni, Dothiorella symphoricarposicola, Dictyocheirospora rotunda, Fasciatispora arengae, Grammothele brasiliensis, Lasiodiplodia iraniensis, Lembosia xyliae, Morenoina palmicola, Murispora cicognanii, Neodidymelliopsis farokhinejadii, Neolinocarpon rachidis, Nothophoma quercina, Peroneutypa scoparia, Pestalotiopsis aggestorum, Pilidium concavum, Plagiostoma salicellum, Protofenestella ulmi, Sarocladium kiliense, Tetraploa nagasakiensis and Vaginatispora armatispora).

Fungi have been often neglected, despite the fact that they provided penicillin, lovastatin and many other important medicines. They are an understudied, but essential, fascinating and biotechnologically useful group of organisms. The study of fungi in northern Thailand has been carried out by us since 2005. These studies have been diverse, ranging from ecological aspects, phylogenetics with the incorportation of molecular dating, taxonomy (including morphology and chemotaxonomy) among a myriad of microfungi, to growing novel mushrooms, and DNA-based identification of plant pathogens. In this paper, advances in understanding the biodiversity of fungi in the region are discussed and compared with those further afield. Many new species have been inventoried for the region, but many unknown species remain to be described and/or catalogued. For example, in the edible genus Agaricus, over 35 new species have been introduced from northern Thailand, and numerous other taxa await description. In this relatively well known genus, 93% of species novelty is apparent. In the microfungi, which are relatively poorly studied, the percentage of novel species is, surprisingly, generally not as high (55–96%). As well as Thai fungi, fungi on several hosts from Europe have been also investigated. Even with the well studied European microfungi an astounding percentage of new taxa (32–76%) have been discovered. The work is just a beginning and it will be a daunting task to document this astonishingly high apparent novelty among fungi.

Fungi are eukaryotes that play essential roles in ecosystems. Among fungi, Basidiomycota is one of the major phyla with more than 40,000 described species. We review species diversity of Basidiomycota from five groups with different lifestyles or habitats: saprobic in grass/forest litter, wood-decaying, yeast-like, ectomycorrhizal, and plant parasitic. Case studies of Agaricus, Cantharellus, Ganoderma, Gyroporus, Russula, Tricholoma, and groups of lichenicolous yeast-like fungi, rust fungi, and smut fungi are used to determine trends in discovery of biodiversity. In each case study, the number of new species published during 2009–2020 is analysed to determine the rate of discovery. Publication rates differ between taxa and reflect different states of progress for species discovery in different genera. The results showed that lichenicolous yeast-like taxa had the highest publication rate for new species in the past two decades, and it is likely this trend will continue in the next decade. The species discovery rate of plant parasitic basidiomycetes was low in the past ten years, and remained constant in the past 50 years. We also found that the establishment of comprehensive and robust taxonomic systems based on a joint global initiative by mycologists could promote and standardize the recognition of taxa. We estimated that more than 54,000 species of Basidiomycota will be discovered by 2030, and estimate a total of 1.4–4.2 million species of Basidiomycota globally. These numbers illustrate a huge gap between the described and yet unknown diversity in Basidiomycota.

The recognition of taxonomic ranks in the Linnean classification system is largely arbitrary. Some authors have proposed the use of divergence time as a universally standardized criterion. Agaricus (Agaricaceae, Agaricales) is a mushroom genus that contains many species of high commercial value. Recent studies using ITS sequence data discovered 11 new phylogenetic lineages within the genus, however their taxonomic ranks were uncertain due to the lack of criteria to define them within traditional taxonomy. In this study, we analyzed ITS sequence data from 745 collections (nearly 600 being newly generated) including 86 from type specimens of previously recognized subgenera and sections. Many monophyletic groups were recognized, but most basal relationships were unresolved. One hundred and fourteen representatives of the identified ITS clades were selected in order to produce a multi-gene phylogeny based on combined LSU, tef-1α, and rpb2 sequence data. Divergence times within the multi-gene phylogeny were estimated using BEAST v1.8. Based on phylogenetic relationships and with respect to morphology, we propose a revised taxonomic system for Agaricus that considers divergence time as a standardized criterion for establishing taxonomic ranks. We propose to segregate Agaricus into five subgenera and 20 sections. Subgenus Pseudochitonia is substantially emended; circumscription of the subgenera Agaricus and Flavoagaricus is restricted to taxa of sections Agaricus and Arvenses, respectively; and two new subgenera (Minores and Spissicaules) are introduced. Within Pseudochitonia, sections Bivelares, Brunneopicti, Chitonioides, Nigrobrunnescentes, Sanguinolenti and Xanthodermatei are maintained, but the latter two are reduced because we raise subsection Bohusia to sectional rank and a clade within section Xanthodermatei is formally introduced as section Hondenses; and sections Rubricosi, Crassispori, Flocculenti, and Amoeni are introduced. Section Laeticolores is placed in the subgenus Minores and sections Rarolentes and Subrutilescentes are placed in the subgenus Spissicaules. Twenty-two new species belonging to various sections are described. This work exemplifies that ITS data, while useful at lower taxonomic levels (i.e., detection of species and species groups), are of limited value for inferring deeper phylogenetic relationships. Finally, we suggest that the establishment of a standardized taxonomic system based on divergence times could result in a more objective, and biologically more meaningful, taxonomic ranking of fungi.