Fungalpedia – Note 2655, Oxnerella

 

Oxnerella S.Y. Kondr., Lőkös & Hur.

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

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

Classification: Physciaceae, Caliciales, Lecanoromycetidae, Lecanoromycetes, Pezizomycotina, Ascomycota, Fungi

Oxnerella was introduced by Kondratyuk et al. (2014b) to accommodate the lichen species O. safavidiorum. Subsequent phylogenetic analysis by Kondratyuk et al. (2021), based on ITS and mtSSU sequences, revealed that Oxnerella forms part of the Phaeophyscia sensu lato subclade. As a result, the genus was placed within Physciaceae (Caliciales). The species Oxnerella afghanica, originally described as Rinodina afghanica (Steiner et al. 1987), was then designated as the type species, while the original type, O. safavidiorum, was transferred to Lecania (Kondratyuk et al. 2021). Additionally, Oxnerella castanomelodes was reclassified from Rinodina castanomelodes (Kondratyuk et al. 2021). 

This genus is characterized by a crustose, areolate thallus that ranges in color from ochraceous to rusty brown. The hypothallus is concolorous with the thallus, also ochraceous. Apothecia are lecanorine, with convex, black or blackish discs. The cortical layer of the thalline exciple exhibits a palisade plectenchymatous structure, while the true exciple is paraplectenchymatous. The hymenium is dark and brownish, with a blackish, K– epihymenium. Paraphyses have swollen apical cells, and the subhymenium is hyaline. Asci are of the Biatora-type, and ascospores are 1-septate, constricted at the septum (Kondratyuk et al. 2014b). There are two species recognized within this genus: one lichenicolous and one lichen-forming.

Type species: Oxnerella afghanica (M. Steiner & Poelt) S.Y. Kondr., Lőkös & Hur, on Caloplaca polycarpoides (Kondratyuk et al. 2021).

= Rinodina afghanica M. Steiner & Poelt (Steiner et al. 1987).

Other accepted species: Species Fungorum – search Oxnerella.

Figure 1 – Oxnerella afghanica redrawn from Steiner et al. (1987). a Paraphyses. b Ascospores. Scale bars: a, b = 10 μm.

 

References

Kondratyuk SY, Lokos L, Kim JA, Kondratiuk AS et al. 2014b – Oxnerella safavidiorum Gen. Et spec. Nov. (lecanoromycetidae, ascomycota) from Iran (Asia) proved by phylogenetic analysis. Acta Botanica Hungarica 56, 379–398.

Kondratyuk SY, Lokos L, Kärnefelt I, Thell A et al. 2021 – Contributions to Molecular Phylogeny of Lichen-Forming Fungi 2. Review of Current Monophyletic Branches of the Family Physciaceae. Acta Botanica Hungarica 63, 351–390.

Steiner M, Poelt J. 1987 – Drei parasitische Flechten auf Caloplaca polycarpoides/Three parasitic lichens on Caloplaca polycarpoides. Plant systematics and evolution, 133–141.

 

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 1 July 2026

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