Fungalpedia – Note 2616, Zwackhiomyces

 

Zwackhiomyces Grube & Hafellner.

Citation when using this data: Meng QF et al. – Fungalpedia.

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1.

Classification: Xanthopyreniaceae, Collemopsidiales, Dothideomycetes orders incertae sedis, Pezizomycotina, Ascomycota, Fungi.

Zwackhiomyces was established by Grube et al. (1990) to accommodate nine species, including the type species Z. coepulonus (Norman) Grube & R. Sant. The genus is characterized by pear-shaped to globose, sessile pseudothecia with a slightly ornamented peridium; filamentous, branched paraphysoids with anastomosing elements embedded in a viscous matrix; and cylindrical to broadly cylindrical bitunicate asci that are 4-, 6-, or 8-spored. The ascospores are hyaline, two-celled, with the upper cell larger and broader than the lower cell. The pycnidia resemble the ascomata in shape and wall structure but are smaller. Conidiogenous cells are slender, bottle-shaped, and colorless, producing hyaline, single-celled, short rod-shaped pycnospores (Grube et al. 1990). 

Diederich et al. (2018a) listed 35 species in Zwackhiomyces, and six additional species have since been introduced: Z. fuscatus Poumarat, Daval & Cl. Roux, Z. khodosovtsevii Darmostuk, Z. lecaniae D. Gonnet, O. Gonnet & Cl. Roux, Z. lecideae Y. Joshi, Z. parmotrematis van den Boom, and Z. protoparmeliopsidis Y. Joshi (Diederich et al. 2018a, van den Boom et al. 2018b, Joshi et al. 2020b, Darmostuk 2021b, Joshi 2022b, Poumarat 2022, Roux 2023). To date, Zwackhiomyces comprises 44 recognized species according to Index Fungorum (2025), with three gene sequences available in GenBank.

Type species: Zwackhiomyces coepulonus (Norman) Grube & R. Sant.

= Arthopyrenia coepulona Norman

Other accepted species: Species Fungorum – search Zwackhiomyces

Figure 1 – Zwackhiomyces coepulonus redrawn from Grube et al. (1990). a Asci and paraphysoid. b Ascospores. Scale bars: a = 20 μm, b = 10 μm.

 

References

Darmostuk VV. 2021b – Lichenicolous fungi on Verrucaria s. lat. in Ukraine with the description of Zwackhiomyces khodosovtsevii sp. nov. and a key to the lichenicolous fungi on Verrucaria s. lat. Botanica Serbica 45 (2), 293–301.

Diederich P, Lawrey JD, Ertz D. 2018a – The 2018 classification and checklist of lichenicolous fungi, with 2000 non-lichenized, obligately lichenicolous taxa. The Bryologist 121 (3), 340–425.

Grube M, Hafellner J. 1990 – Studien an flechtenbewohnenden Pilzen der Sammelgattung Didymella (Ascomycetes, Dothideales). Nova Hedwigia 51 (3–4), 283–360.

Joshi Y, Kumar P, Yadav AL, Suda N et al. 2020b – Distribution and diversity of lichenicolous fungi from western Himalayan Cold Deserts of India, including a new Zwackhiomyces species. Sydowia 73, 171–183.

Joshi Y. 2022b – Three new species of lichenicolous fungi from India. Kew Bulletin 77 (1), 333–340.

Poumarat S. 2022 – Zwackhiomyces fuscatus Poumarat, Daval et Cl. Roux sp. nov., champignon lichénicole (Ascomycota, Xanthopyreniaceae) parasite d’Acarospora fuscata. Bull. Soc. linn. Provence 73, 43–50.

Roux C. 2023 – Zwackhiomyces lecaniae D. Gonnet, O. Gonnet et Cl. Roux sp. nov., champignon lichénicole non lichénisé, et clé des Zwackhiomyces (Ascomycota, Xanthopyreniaceae). Bull. Soc. linn. Provence 74, 131–146.

van den Boom PPG, Sipman HJM, Divakar PK, Ertz D. 2018b – New or interesting records of lichens and lichenicolous fungi from Suriname, with descriptions of eight new species. Ascomycete.org 10 (6), 244–258.

 

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 16 June 2026

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