Fungalpedia – Note 2365, Prosthemium
Prosthemium. Kunze.
Citation when using this data: Yuan HS et al. 2020 – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Pleomassariaceae, Pleosporales, Pleosporomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Notes: The genus Prosthemium was introduced by Kunze (1817) with Prosthemium betulinum as the type species. The characters that define the genus are immersed, erumpent ascomata, a dense, cellular, filiform hamathecium, broadly cylindrical to broadly cylindro-clavate asci, muriform brown to golden brown ascospores. The asexual morph is coelomycetous producing staurosporous brown macroconidia as well as ellipsoid guttulate microconidia. Seven species are recorded in Prosthemium. Species of Prosthemium can be found worldwide especially in Europe. We illustrate the sexual and asexual morph of P. betulinum as a new record from Italy.
Type species: Prosthemium betulinum Kunze, in Kunze & Schmidt, Mykologische Hefte (Leipzig) 1: 18 (1817).
Other accepted species: Species Fungorum – search Prosthemium.
Figure 1 – Prosthemium betulinum. (MFLU 17-0975, a new geographical record).
a,b Appearance of ascomata on host surface. c Vertical section through the ascomata. d Peridium e–g Asci. h Asci showing ocular chamber i Ascospore in Indian ink showing sheath
j-l Ascospores m Germinating ascospores n,o Culture characteristics on MEA ( n: above view; o: reverse view) Scale bars: a = 1000 μm, b = 2000 μm, c = 400 μm, d = 40 μm, e–g = 100 μm, h–l = 20 μm, m = 50 μm
References
Kunze G (1817). Zehn neue Pilzgattungen. Mykologische Hefte 1: 1–18
Entry by
Hai-Sheng Yuan, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, People’s Republic of China, University of the Chinese Academy of Sciences, Beijing, 100049, People’s Republic of China
Published online 30 April 2026