Fungalpedia – Note 2823, Gymnoascoideus
Gymnoascoideus. G.F. Orr, K. Roy & G.R. Ghosh.
Citation when using this data: Kandemir H et al. 2022 – Fungalpedia.
Index Fungorum, Facesoffungi, MycoBank, GenBank
Classification: Gymnoascaceae, Onygenales, Eurotiomycetidae, Eurotiomycetes, Pezizomycotina, Ascomycota, Fungi
Orr et al. (1977b) described Gymnoascoideus petalosporus with thick- and smooth-walled ascospores in a petaloid arrangement in the asci. Correctly identified strains suggest a preference for keratinous substrates such as human skin (CBS 630.72), horse skin (UAMH 3592), horn (UAMH 3525) and feathers (O-1299), in addition to soil (O-2013) (Orr et al. 1977b). Von Arx (1977) examined some of these strains and noted that they were variable in culture morphology, peridial hyphal formation and ascospore size. He considered the Gymnoascoideus (in the literature often as “Gymnoascoides”) intermediate between Arachniotus and Gymnoascus.
Phylogenetically, the nearest neighbor of G. petalosporus is G. boliviensis (98% ITS similarity between AJ315828 and AB361639; 526 bp), which differs by its brown ascomata and ascospores without equatorial thickening (Guarro et al. 1992b). Gymnoascus boliviensis has been reported to form clusters of asci and lack discrete ascocarps on sterilized soil supplemented with hair. The presence of interwoven peridial hyphae and ascospores in a petaloid pattern and limited growth at 37 °C have also been reported (Guarro et al. 1992b).
Type species: Gymnoascoideus petalosporus Orr, Roy & Ghosh—Mycotaxon 5(2): 460.
Other accepted species: Species Fungorum – search Gymnoascoideus.
References
Guarro J, Ulfig K, De Vroey C 1992b – A new keratinophilic Gymnoascus from Bolivian soil. Mycotaxon 45:317–322.
Orr GF 1977b – Another genus of the Gymnoascaceae with swollen septa on peridial elements. Mycotaxon 5(1):283–290.
von Arx JA 1977 – Notes on Gymnoascaceae. Persoonia 9(3):393–400.
Entry by
Hazal Kandemir, Center of Expertise in Mycology, Radboud University Medical Center/Canisius Wilhelmina Hospital, Nijmegen, The Netherlands, Division of Medical Mycology, Faculty of Medicine, University of Cukurova, Adana, Turkey
Published online 25 June 2026