Fungalpedia – Note 2627, Keratosphaera
Keratosphaera H.B.P. Upadhyay.
Citation when using this data: Meng QF et al. – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Dothideomycetes genera incertae sedis, Pezizomycotina, Ascomycota, Fungi.
Keratosphaera was established by Upadhyay (1964) to accommodate the type species K. batistae H.B.P. Upadhyay, which is lichenicolous, growing on the thallus of Mazosia phyllosema (Nyl.) Zahlbr. This genus is characterized by lichenicolous ascomata which are perithecioid, furnished with dark brown and unbranched setae above, (sub-)globose, ellipsoid to broadly ovoid, more or less hyaline to black but setae always dark brown. Asci are fissitunicate, often with a protruded endoascus, ovoid, elliptical or cylindrical, shortly or not distinctly stipitate, 6- to 8-spored. Ascospores are hyaline, ellipsoid to obovoid, with rounded ends, 1-septate, slightly or not constricted at the septum, smooth, without a gelatinous sheath (Matzer 1996). Matzer (1996) introduced another three species, Keratosphaera dimerellae growing on Dimerella sp., K. furcatiseta and K. porinae rowing on Porina sp. Flakus et al. introduced two species separately, but one grows on leaves of Arecaceae and another one, Keratosphaera antoniana is lichenicolous, growing on Trichothelium (Flakus et al. 2008, Farkas 2010). Up to now, six records of this genus in Index Fungorum (2025), with five being lichenicolous. However, no molecular data is available for this genus, so its placement remains unclear. Keratosphaera was tentatively placed within Dothideomycetes genera incertae sedis by Hyde et al. (2024).
Type species: Keratosphaera batistae H.B.P. Upadhyay.
Other accepted species: Species Fungorum – search Keratosphaera.
Figure 1 – Keratosphaera batistae redrawn from Matzer (1996), a Ascomatal setae. b Ascus with ascospores. c ascus with ruptured exoascus and protruded endoascus. d Ascospores. Scale bars: a–c = 10 μm, d = 5 μm.
References
Upadhyay H. 1964 – Three new hyperparasites for Mazosia phyllosema (Nyl.) A. Zahlbr. from Amazonas valley. Publicações do Instituto de Micologia da Universidade do Recife 402, 1–11.
Entry by
Meng QF, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand and School of Public Health, Zunyi Medical University, Guizhou 563000, China.
Published online 23 June 2026