Fungalpedia – Note 25 Pseudomicrothecium


Citation: Bhunjun et al. 2023 – Fungalpedia, genera described in 2018, Mycosphere (in press)


Pseudomicrothecium Y. Marín, Stchigel, Guarro & Cano

Index FungorumFacesoffungi, MycoBank, GenBank, Fig. 1            

Pseudomicrothecium was introduced as a novel genus with the type species P. subterraneum (L. Fan, C.L. Hou, P.F. Cannon & Y. Li) Y. Marín, Stchigel, Guarro & Cano by  Marín-Felix et al. (2018). Pseudomicrothecium subterraneum was found as a mycoparasite on the tissue of Tuberaceae (Tuber indicum and T. huidongense) in China (Fan et al. 2012) and it is the only species listed in Index Fungorum (2022). Pseudomicrothecium is closely related to Microthecium and Scopinella (Marín-Felix et al. 2018). However, Microthecium has more than two ascospores within its asci and Scopinella has long necked ostiolate ascomata and cuboid to ellipsoidal ascospores with two prominent longitudinal germ slits (Marín-Felix et al. 2018). Pseudomicrothecium is characterized by astromatic ascomata that are pale brown to brown, immersed, solitary or gregarious, globose, cleistothecial, glabrous or setose, translucent, non-ostiolate and become black as the ascospores mature (Fan et al. 2012 Marín-Felix et al. 2018). Asci are 2-spored, thin-walled, short-stipitate, clavate, without apical structures and evanescent. Ascospores are smooth-walled, hyaline and dark brown to black when mature, ellipsoidal to citriform, slightly apiculate at each end, guttulate and have indistinct apical germ pores at both ends (Fan et al. 2012,  Marín-Felix et al. 2018).

Type species: Pseudomicrothecium subterraneum (L. Fan et al.) Y. Marín, Stchigel, Guarro & Cano

Basionym: Melanospora subterranea L. Fan, C.L. Hou, P.F. Cannon & Yu Li


Fig 1: Pseudomicrothecium subterraneum (BJTC FAN1001, holotype). a Peridium and ascospores. b Ascus. c Ascospores. Scale bars: a = 50 µm, b, c = 10 µm. Redrawn from Fan et al. (2012).



Fan, L., Hou, C. L., Cannon, P. F., & Li, Y 2012 A new species of Melanospora on truffles from China. Mycologia, 104(6), 1433–1442.

Huang, S. K., Hyde, K. D., Maharachchikumbura, S. S. N., McKenzie, E. H. C., & Wen, T. C 2021 – Taxonomic studies of Coronophorales and Niessliaceae (Hypocreomycetidae). Mycosphere, 12(1), 875–992.

Marín-Felix, Y., Guarro, J., Cano-Lira, J. F., García, D., Miller, A. N., & Stchigel, A. M 2018 – Melanospora (Sordariomycetes,Ascomycota) and its relatives. MycoKeys, 44, 81–122.


Entry by         

Hsan Win, Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Muang, Chiang Rai, Thailand.


(Edited by Chitrabhanu S. Bhunjun and Kevin D. Hyde)