Fungalpedia – Note 3283, Eurotiomycetes
Eurotiomycetes O.E. Erikss. & Winka, Myconet 1(1): 6 (1997).
Citation when using this data: Wijayawardene NN et al. 2024 – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Pezizomycotina, Ascomycota, Dikarya, Fungi.
Thallus: Yeast-like to filamentous. Sexual morph: Stromata occasionally present, reduced, usually pulvinate or (sub)globose, sometimes stipitate, white, brown or black. Ascomata apothecial, ascostromatal, cleistothecial, gymnothecial, perithecioid, or mazaediate, mostly (sub)globose, pyriform or variously shaped, sometimes setose or with dictinct peridial appendages, light-coloured to black, solitary to aggregated. Hamathecium absent or including paraphyses, pseudoparaphyses, periphysoids and periphyses in different combinations. Asci usually 8-spored, sometimes 2-spored or polysporous, mostly (sub)globose, clavate or obpyriform, unitunicate or bitunicate, with fissitunicate to evanescent dehiscence. Ascospores usually allantoid, bivalved, ellipsoidal, globose, oblate, (ob)ovoid, reniform or star-shaped, aseptate, transversely septate or dictyoseptate, hyaline, light-coloured or brown, smooth or showing an equatorial furrow, rim or crests, a reticulum, ridges, spines, warts or other ornamentations, sometimes surrounded by a sheath. Asexual morph: coelomycetous or hyphomycetous. Coelomycetes: Conidiomata pycnidial or pycnothyrial, with or without a central ostiole, commonly flat to globose, brown, immersed to erumpent. Conidiomatal wall often of textura angularis or textura epidermoidea at the outer portion, inner wall covered with hyaline to dark brown, ampulliform, cylindrical, ellipsoidal, fusiform, oval or lens-shaped phialidic conidiogenous cells, or with pale brown toruloid conidiophores producing cheiroid conidia. Conidia aseptate, mostly cylindrical to ellipsoid, hyaline or cheiroid, consisting of a central globose, medium brown, verruculose cell giving rise to up to 6 radiating arms of subglobose to ellipsoidal cells, each forming lateral branches. Hyphomycetes: Conidiomata present or absent, scattered or aggregated, sporodochia or synnemata. Setae sometimes present. Conidiophores micronematous to macronematous, hyaline to brown, solitary to fasciculate, aseptate or septate, simple or branched, smooth-walled to verrucose, Conidial ontogeny enteroblastic, holoblastic, holothallic or thallic-arthric. Conidiogenous cells intercalary, lateral or terminal, sometimes extending percurrently or sympodially, sometimes denticulate or with dark or refractive scars. Conidia solitary or produced in mucilaginous masses or chains, aseptate, transversely septate or dictyoseptate, highly diverse in shape, usually (sub)cylindrical, (ob)clavate, doliiform, ellipsoid, (sub)globose, falcate, fusiform or guttuliform, smooth-walled or ornamented, usually with more or less developed spines or warts, with or without a basal frill, secession rhexolytic or schizolytic.
Life modes and distribution: Members of Eurotiomycetes are abundant both in terrestrial and aquatic ecosystems worldwide, occurring in an extremely broad range of habitats. While most of these fungi are degraders of decaying material of plant or animal origin, many species cause diseases in animals (e.g. Exophiala cancerae, an agent of Lethargic Crab Disease in the mangrove crab Ucides cordatus fide de Hoog et al. 2011) (Table 11; Wijayawardene NN et al. 2024), plants (e.g. Dolabra nepheliae on rambutan and lychee fide Rossman et al. 2010), or other fungi (e.g. Cladophialophora pucciniophila on Puccinia polygoni-amphibii fide Park and Shin 2011). This order includes a remarkably high number of clinically relevant species causing diverse pathologies in humans and other animals, including agents of life-threatening systemic mycoses, such as blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis, as well as fungi causing chromoblastomycosis, dermatophytosis, hyalohyphomycosis, mycetoma, and phaeohyphomycosis (de Hoog et al. 2020). Certain lineages in Eurotiomycetes contain lichenized fungi, e.g. Pyrenulales, Verrucariales, and some Celotheliaceae (Gueidan et al. 2014; Pykälä et al. 2020, Miranda-González et al. 2022) or lichenicolous species (e.g. Knufia peltigerae and Sclerococcum spp. fide Untereiner et al. 2011; Diederich et al. 2018).
Notes: The class Eurotiomycetes was erected by Eriksson and Winka (1997) based on phylogenetic analysis of the 18S rRNA gene (SSU). The original circumscription of this class included most fungi referred to as “Plectomycetes”, which were roughly characterized by thin-walled prototunicate asci (unitunicate asci with walls which disintegrate at maturity to release the ascospores passively within the ascoma), ascomata lacking a distinct hymenial layer and with asci scattered within the ascomatal cavity, aseptate ascospores, ascomata gymnothecial to cleistothecial, the latter sometimes produced within a stroma, and morphologically diverse blastic or thallic asexual morphs (Alexopoulos et al. 1996; Geiser et al. 2006). Eriksson and Winka (1997) included two orders in this class, i.e. Eurotiales and Onygenales. The former included the families Elaphomycetaceae, Monascaceae and Trichocomaceae, and the latter included Arthrodermataceae, Ascosphaeraceae, Eremascaceae, Gymnoascaceae and Onygenaceae. The monophyly of this class was confirmed subsequently in a SSU-based phylogenetic analysis by Geiser and LoBuglio (2001). Unexpectedly, early phylogenetic studies (Spatafora 1995; Berbee 1996; Silva-Hanlin and Hanlin 1999) revealed that the “monophyletic Plectomycetes” shared a common ancestry with members of the order Chaetothyriales, which produce perithecioid ascomata and bitunicate asci with an active, fissitunicate spore release mechanism (Müller et al. 1987; Barr 1991). The order Coryneliales has been considered a “missing link” between the “monophyletic Plectomycetes” and chaetothyrialean genera and related fungi. Coryneliales produce ascolocular ascomata and asci which are initially bitunicate, but whose outer layer breaks away early in their development, so that asci appear unitunicate at maturity, releasing spores passively by degradation of the inner ascal wall (Johnston and Minter 1989). Multi-locus phylogenetic studies placed this order basal to the clade comprising Eurotiales and Onygenales (Geiser et al. 2006), supporting the view that the ascomata of Plectomycetes evolved by loss of the bitunicate ascus and its active spore release mode (Eriksson 1982). The boundaries of Eurotiomycetes have been broadened significantly in recent years and, at present, it includes six ecologically, morphologically, and phylogenetically diverse subclasses, i.e. Chaetothyriomycetidae, Coryneliomycetidae, Cryptocaliciomycetidae, Eurotiomycetidae, Mycocaliciomycetidae, and Sclerococcomycetidae (Prieto et al. 2021). The class Eurotiomycetes currently encompasses twelve orders, 34 families and ca. 291 genera.
Numerous species of Eurotiomycetes are pleomorphic, producing sexual and asexual morphs which were traditionally named separately. Recent phylogenetic studies (Réblová et al. 2013; Samson et al. 2014; Yilmaz et al. 2014; Diederich et al. 2018; Sun et al. 2019; Houbraken et al. 2020; Kandemir et al. 2022) have applied unitary nomenclature in different genera in this class, in the pursuit of taxonomic stability.
Type order: Eurotiales G.W. Martin ex Benny & Kimbr., Mycotaxon 12(1): 23 (1980).
Type family: Aspergillaceae Link, Abh. dt. Akad. Wiss. Berlin 1824: 165. 1826.
= Eurotiaceae Clem. & Shear, Gen. fung., Edn 2 (Minneapolis): 50 (1931).
Type genus: Aspergillus P. Micheli ex Haller, Hist. stirp. Helv. (Bernae) 3: 113 (1768).
Type species: Aspergillus glaucus (L.) Link 1809 (Designated by Clements & Shear, Gen. fung., Edn 2 (Minneapolis): 386. 1931).
= Eurotium herbariorum (F.H. Wigg.) Link ex Nees, Syst. Pilze (Würzburg): 96 (1816) [1816-17].
Other accepted species: Species Fungorum – search Eurotiomycetes.
Figure 1 – Macro and micro morphological characteristics of eurotiomycetous taxa. a, g-k ascomata (a Agonimia tristicula (Verrucariaceae, Verrucariales, Chaetothyriomycetidae; g Pyrgillus americanus (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae); h Chaetothyrium guaraniticum (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae); i: Dolabra nepheliae (Celotheliaceae, Phaeomoniellales, Chaetothyriomycetidae); j Coccodinium bartschii (Coccodiniaceae, Chaetothyriales, Chaetothyriomycetidae); k Pyrenowilmsia ferruginosa (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). b Synnema of Penicilliopsis clavariiformis (Aspergillaceae, Eurotiales, Eurotiomycetidae). c Ascostroma of Corynelia tripos (Coryneliaceae, Coryneliales, Coryneliomycetidae). d Stipe with volva of Pseudotulostoma volvatum (Elaphomycetaceae, Eurotiales, Eurotiomycetidae). e Apothecia of Mycocalicium parietinum (Mycocaliciaceae, Mycocaliciales, Mycocaliciomycetidae). f Stromata Dendrosphaera eberhardtii (Aspergillaceae, Eurotiales, Eurotiomycetidae). h Ascomata with black setae of Chaetothyrium guaraniticum (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). l Squash mount of ascoma of Actinocymbe separato-setosa (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). m,n,p Vertical section of ascoma (m Dermatocarpon miniatum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae); n Dermatocarpella yoshimurae (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). o Vertical section of apothecia of Phaeocalicium praecedens (Mycocaliciaceae, Mycocaliciales, Mycocaliciomycetidae). q-ai Asci with ascospores. (q Phaeosaccardinula diospyricola (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). r Samarospora potamogetonis (Eurotiomycetidae incertae sedis). s Dermatocarpon miniatum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). t Corynelia clavata (Coryneliaceae, Coryneliales, Coryneliomycetidae). u Caliciopsis pinea (Coryneliaceae, Coryneliales, Coryneliomycetidae). v Fitzpatrickella operculata (Coryneliaceae, Coryneliales, Coryneliomycetidae). w Sporodictyon schaererianum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). x Actinocymbe separato-setosa (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). y Muellerella polyspora (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). z Clypeopyrenis microsperma (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). ab Melanotheca coccorum (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). ac Pyrenowilmsia ferruginosa (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). ad Heufleridium pentagastricum (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). ae Dolabra nepheliae (Celotheliaceae, Phaeomoniellales, Chaetothyriomycetidae). af Parathelium polysemum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). ag Phaeocalicium praecedens (Mycocaliciaceae, Mycocaliciales, Mycocaliciomycetidae). ah Chaenothecopsis rubescens (Mycocaliciaceae, Mycocaliciales, Mycocaliciomycetidae). ai Moriola descensa (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). aj-at Ascospores. (aj Verrucaria tartarina (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). ak Rhaphidicyrtis trichosporella (Incertae sedis, Pyrenulales, Chaetothyriomycetidae). al Tripospora tripos (Coryneliaceae, Coryneliales, Coryneliomycetidae). am Samarospora potamogetonis (Eurotiomycetidae genera incertae sedis,). an Lagenulopsis bispora (Coryneliaceae, Coryneliales, Coryneliomycetidae). ao Heterocarpon ochroleucum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). ap Parapyrenis aurora (Pyrenulaceae, Pyrenulales, Chaetothyriomycetidae). aq Phaeospora rimosicola (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). ar Ceratocarpia cactorum (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). as Bicornispora exophiala (Rutstroemiaceae, Helotiales, Leotiomycetidae). at Sporodictyon schaererianum (Verrucariaceae, Verrucariales, Chaetothyriomycetidae). au, av Spores (au Coccodinium bartschii (Coccodiniaceae, Chaetothyriales, Chaetothyriomycetidae). av Chaetothyrium spinigerum (Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae). Scale bars: a,b = 2000 µm, c,f = 1000 µm, e,h,i,k-o = 100 µm, g = 500 µm, p = 50 µm, q, w, ad,ai,av = 20 µm, r-v, x-ac,ae-ah,ak,al,as-au = 10 µm, aj, am-ar = 5 µm. (photo credit to Qing Tian).
References
Alexopoulos CJ, Mims CW, Blackwell M. 1996 – Introductory Mycology, 4th Edition. John Wiley & Sons Inc. New York.
Eriksson OE, Winka W. 1997 – Supraordinal taxa of Ascomycota. Myconet. 1:1–16.
Entry by
Nalin N. Wijayawardene, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China, Tropical Microbiology Research Foundation, 96/N/10, Meemanagoda Road, 10230 Pannipitiya, Sri Lanka, Department of Bioprocess Technology, Faculty of Technology, Rajarata University, Sri Lanka
Published online 25 September 2026