Biology:Orphniospora

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Orphniospora is a small genus of lichen-forming fungi in the family Fuscideaceae. The genus was established in 1874 by the German lichenologist Gustav Wilhelm Körber and comprises three saxicolous (rock-dwelling) crustose species. These lichens are distinguished by their unusual spores, which are nearly spherical, single-celled, and produced only a few at a time in each spore-bearing structure. Despite being placed in the family Fuscideaceae in recent classifications, molecular studies have shown that Orphniospora does not actually belong to this family, leaving its correct taxonomic position uncertain.

Taxonomy

Orphniospora was circumscribed by the German lichenologist Gustav Wilhelm Körber in 1874. He created the genus for crustose lichens whose spores are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]—single-celled or non-septate—almost spherical, and produced only a few per ascus (oligosporous). This spore morphology sets the genus apart from typical [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] lichens.[1] In his protologue Körber described a uniformly crustose thallus and black, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] apothecia whose spore-bearing layer overlies a simple brown [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]. He also recognised a second species, O. groenlandica, which has a thin, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] thallus merging with the substrate and rare, terminally flattened apothecia with delicate margins. Further diagnostic characters include a violet-tinged hymenium with [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (stuck-together) paraphyses and a granular brown hypothecium, together with the distinctive spores.[1] The correct taxonomic placement of Orphniospora is unclear.[2] Although it has been placed in the family Fuscideaceae in recent fungal classifications,[3][4][5] molecular phylogenetics work has shown that it does not belong to this family.[6][2]

Description

The thallus of Orphniospora species forms a crust tightly attached to the substrate, breaking into small, tile-like [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] that give the surface a mosaic appearance. A thin, blackish [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]—essentially a boundary zone where no lichenised tissue develops—often outlines the colony. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] partner is a single-celled green alga ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]). Black, disc-shaped apothecia (fruiting bodies) arise directly from the thallus without a surrounding rim of thallus tissue. Their surfaces are sometimes dusted with a faint rusty or ochre powder ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]). Both the outer wall ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) and the layer beneath the spore-producing tissue ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) are dark brown, whereas the hymenium—the fertile layer in which spores develop—is colourless but may turn pale blue with iodine staining.[2] Under the microscope, the hymenium is interlaced with slender, mostly unbranched paraphyses—sterile filaments that separate the developing asci (spore sacs) and can fuse to one another (anastomose). Each club-shaped ascus contains eight ascospores and shows a narrow, weakly iodine-reactive apical dome, overlaid by a more diffuse cap that turns a strong blue in combined potassium iodide tests (K/I+). The ascospores themselves are thick-walled, ellipsoidal, and vary from colourless to dark olive-brown; they may be single-celled or have an indistinct median septum. Asexual reproduction occurs in tiny, immersed pycnidia that release colourless, rod-shaped conidia formed on simple cylindrical [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]. Standard thin-layer chromatography has failed to detect any secondary metabolites in the genus.[2]

Ecology

Orphniospora lichen are saxicolous, and grow on hard siliceous rocks.[2]

Species

Species Fungorum (in the Catalogue of Life) accepts three species in Orphniospora:[5]

  • Orphniospora groenlandica Körb. (1874)
  • Orphniospora moriopsis (A.Massal.) D.Hawksw. (1982)[7]
  • Orphniospora mosigii (Körb.) Hertel & Rambold (1988)[8]

References

  1. ↑ 1.0 1.1 Körber, G.W. (1874). "4. Flechten. Die Zweite Deutsche Nordpolarfahrt" (in de). Die zweite Deutsche Nordpolarfahrt in den Jahren 1869 und 1870, unter Führung des Kapitän Karl Koldewey. 2. Leipzig: F.A. Brockhaus. pp. 75–82 [81]. https://www.biodiversitylibrary.org/page/13186175. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Cannon, P.; Coppins, B.; Aptroot, A.; Sanderson, N.; Simkin, J. (2025). Miscellaneous lichens and lichenicolous fungi, including Aphanopsis and Steinia (Aphanopsidaceae), Arthrorhaphis (Arthrorhaphidaceae), Buelliella, Hemigrapha, Melaspileella, Stictographa and Taeniolella (Asterinales, family unassigned), Phylloblastia (Chaetothyriales, family unassigned) Cystocoleus (Cystocoleaceae), Sclerococcum (Dactylosporaceae), Eiglera (Eigleraceae), Epigloea (Epigloeaceae), Euopsis (Harpidiaceae), Lichenothelia (Lichenotheliaceae), Lichinodium (Lichinodiaceae), Melaspilea (Melaspileaceae), Epithamnolia and Mniaecia (Mniaeciaceae), Lichenostigma (Phaeococcomycetaceae), Pycnora (Pycnoraceae), Racodium (Racodiaceae), Chicitaea and Loxospora (Sarrameanaceae), Schaereria (Schaereriaceae), Strangospora (Strangosporaceae), Botryolepraria and Stigmidium (Verrucariales, family unassigned), and Biatoridium, Mycoglaena, Orphniospora, Piccolia, Psammina and Wadeana (order and family unassigned). Revisions of British and Irish Lichens. 57. p. 62. https://britishlichensociety.org.uk/sites/default/files/Miscellaneous%20genera_0.pdf. open access
  3. ↑ Wijayawardene, N.N.; Hyde, K.D.; Dai, D.Q.; Sánchez-García, M.; Goto, B.T.; Saxena, R.K. et al. (2022). "Outline of Fungi and fungus-like taxa – 2021". Mycosphere 13 (1): 53–453 [164]. doi:10.5943/mycosphere/13/1/2. https://www.researchgate.net/publication/358798332. 
  4. ↑ Hyde, K.D.; Noorabadi, M.T.; Thiyagaraja, V.; He, M.Q.; Johnston, P.R.; Wijesinghe, S.N. et al. (2024). "The 2024 Outline of Fungi and fungus-like taxa". Mycosphere 15 (1): 5146–6239 [5267]. doi:10.5943/mycosphere/15/1/25. https://www.researchgate.net/publication/385939154. 
  5. ↑ 5.0 5.1 "Orphniospora". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/CDT9S. 
  6. ↑ Zahradníková, M. (2017). Taxonomy and phylogeny of the family Fuscideaceae (Umbilicariales, Ascomycota) with special emphasis on Fuscidea. PhD thesis, 88 pp. Bergen: University of Bergen.
  7. ↑ Hawksworth, D.L. (1982). "Changes to the British checklist arising from the abolition of later fungal starting points". The Lichenologist 14 (2): 131–137 [135]. doi:10.1017/S0024282982000279. Bibcode: 1982ThLic..14..131H. 
  8. ↑ Hertel, H.; Rambold, G. (1988). "Lecidea mosigii (Kirb.) Anzi – eine Art der Gattung Orphniospora Körb. (Fuscideaceae, Teloschistales)" (in de). Mitteilungen aus der Botanischen Staatssammlung München 27: 111–123. 

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Wikidata ☰ Q7104003 entry



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