Fungalpedia – Note 575, Pleurothyrium
Pleurothyrium 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
Pleurothyrium was introduced by Bubák (1916) as a monotypic genus to accommodate a new combination, P. longissimum (Syn. Leptostroma longissimum). Pleurothyrium contains a single species, P. longissimum, with an asexual morph. It is characterized by stromatic, pycnidial conidiomata with an indistinct ostiole, septate, branched, hyaline conidiophores arising from the basal cells of inner conidiomata wall, holoblastic conidiogenous cells, and septate, filiform, and hyaline conidia (Bubák 1916). Pleurothyrium is phylogenetically uncertain due to the absence of molecular data, thus it has been placed in Ascomycota genera incertae sedis (Li et al. 2020b). Pleurothyrium longissimum has been reported as a saprobic fungus based on several collections of Athyrium spp. including Athyrium filix-femina, and its allies, as well as an unidentified Athyrium sp., likely restricted to the fern host of Athyrium filix-femina (Bubák 1916; French 1989). Fresh collections are needed to place it within a natural group and to confirm the obligate host of Athyrium filix-femina.
Type species: Pleurothyrium longissimum (Lib.) Bubák.
≡ Leptostroma longissimum Lib.
Other accepted species: Species Fungorum – search Pleurothyrium.
Figure 1 – Pleurothyrium longissimum. a Vertical section of conidioma. b Conidiophores, conidiogenous cells and developing conidia. c Conidia. Redrawn from Sutton (1980).
References
French AM 1989 – California plant disease host index. California Department of Food and Agriculture, Division of Plant Industry, Sacramento.
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