Fungalpedia – Note 573, Placothyrium

 

Placothyrium Bubák

Citation when using this data: Zhang et al. 2025 (in prep.) – Fungalpedia, Ascomycota.

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1

Classification: Incertae sedis, Incertae sedis, Incertae sedis, Incertae sedis, Pezizomycotina, Ascomycota, Fungi

Placothyrium was erected by Bubák (1916) as a monotypic genus represented by Placothyrium athyrinum. There are no available molecular data to determine its taxonomic status, and it is currently placed in Ascomycota genera incertae sedis (Lumbsch and Huhndorf 2007; Li et al. 2020b; Wijayawardene et al. 2022; Hyde et al. 2024c). The single species, Placothyrium athyrinum, exhibits a Coelomycetous asexual morph, characterized by being stromatic, mostly unilocular (or occasionally multilocular), pycnidial conidiomata with indistinct ostiole; branched, hyaline conidiophores invested in mucus; holoblastic, integrated conidiogenous cells; 0–2-septate, filiform, hyaline conidia (Sutton 1980; Li et al. 2020b). This conidial trait is similar to some species in Pleurothyrium, Septoria and Sphaerulina.However, they can be distinguished from each other by the absent of conidiophores in Septoria and Sphaerulina (Sutton 1980; Li et al. 2020b). The conidiophores of Pleurothyrium do not have a gelatinous sheath, while Placothyrium athyrinum does (Sutton 1980; Li et al. 2020b). Placothyrium athyrinum was described as a saprobe on Athyrium filix-femina in Germany based on one specimen. Fresh collections are expected to explore its ecology, host relationship, as well as its phylogenetic affiliation with molecular data.

Type species: Placothyrium athyrinum Bubák.

Other accepted species: Species Fungorum – search Placothyrium.

 

 image

Figure 1 – Placothyrium athyrinum. a Vertical section of conidioma. b Conidiophores, conidiogenous cells and developing conidia. c Conidia. Redrawn from Sutton (1980).

 

References

Bubák F 1916 – Systematische untersuchungen einiger farne bewohnenden pilze. Berichte der Deutschen Botanischen Gesellschaft 34:295–332.

Hyde KD, et al. 2024c – The 2024 outline of fungi and fungus-like taxa. Mycosphere (in press).

Li WJ, McKenzie EHC, Liu JK, Bhat DJ, Dai DQ, Camporesi E, Tian Q, Maharachchikumbura SSN, Luo ZL, Shang QJ 2020b – Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100:279–801. 

Lumbsch HT, Huhndorf SM 2007 – Outline of ascomycota–2007. Myconet 13:1–58.

Sutton BC 1980 – The Coelomycetes. Fungi imperfecti with pycnidia, acervuli and stromata. Commonwealth Mycological Institute, Kew, England. 

Wijayawardene NN, Hyde KD, Dai DQ, Sánchez-García M, Goto BT, Saxena R, Erdoğdu M, Selçuk F, Rajeshkumar KC, Aptroot A, Błaszkowski J, Boonyuen N, da Silva GA, de Souza FA, Dong W, Ertz D, Haelewaters D, Jones EBG, Karunarathna SC, Kirk PM, Kukwa M, Kumla J, Leontyev DV, Lumbsch HT, Maharachchikumbura SSN, Marguno F, Martínez-Rodríguez P, Mešić A, Monteiro JS, Oehl F, Pawłowska J, Pem D, Pfliegler WP, Phillips AJL, Pošta A, He MQ, Li JX, Raza M, Sruthi OP, Suetrong S, Suwannarach N, Tedersoo L, Thiyagaraja V, Tibpromma S, Tkalčec Z, Tokarev YS, Wanasinghe DN, Wijesundara DSA, Wimalaseana SDMK, Madrid H, Zhang GQ, Gao Y, Sánchez-Castro I, Tang LZ, Stadler M, Yurkov A, Thines M 2022 – Outline of Fungi and fungus-like taxa – 2021. Mycosphere 13:53–453.

 

Entry by 

Jing-Yi Zhang, School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, 550025, People’s Republic of China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Guizhou Key Laboratory of Agricultural Microbiology, Guizhou Academy of Agricultural Sciences, Guiyang, 550009, People’s Republic of China.

 

Published online 11 June 2025

Back to Glossary Index Page