Lichenostigma

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Genus of fungi

title: "Lichenostigma" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["arthoniomycetes", "ascomycota-genera", "lichenicolous-fungi", "taxa-named-by-josef-hafellner", "taxa-described-in-1983"] description: "Genus of fungi" topic_path: "general/arthoniomycetes" source: "https://en.wikipedia.org/wiki/Lichenostigma" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Genus of fungi ::

| image = Lichenostigma cosmopolites 143712.jpg | image_caption = Lichenostigma cosmopolites | taxon = Lichenostigma | authority = Hafellner (1983) | type_species = Lichenostigma maureri | type_species_authority = Hafellner (1983) | subdivision_ranks = Species | subdivision = | synonyms_ref = | synonyms = *Phaeosporobolus

Lichenostigma is a genus of fungi in the family Phaeococcomycetaceae. It includes several species which are lichenicolous (i.e. parasitic on lichens). The genus was circumscribed in 1983 by the Austrian mycologist Josef Hafellner, with Lichenostigma maureri assigned as the type species.

Description

Lichenostigma is a lichen-dwelling (lichenicolous) fungus that forms no independent thallus and shows little, if any, surface mycelium of its own. Its reproductive structures (ascostromata) appear scattered across the host lichen as dark brown to blackish swellings. When young these bodies are roughly spherical, but they often become elongate with age and may develop a shallow central depression; very old specimens can even mimic the of script lichens. The wall is made of thick-walled, budding cells: the outer layers are dark brown and frequently display a warted or mosaic-like texture, whereas the internal cells remain pale. At maturity the stromata break down irregularly, releasing their ascospores.

Unlike many ascomycetes, Lichenostigma lacks a well-defined hymenial cavity and any . The asci—usually four to eight per stroma—develop directly among the stromatic cells without discrete . They are nearly shperical to broadly ellipsoidal, sit almost on the stroma, and have a very thickened apex with a distinct ; although structurally , they often deliquesce as they ripen. The ascospores are initially colourless, sometimes showing a faint blue staining reaction to potassium iodide in the outer wall, but they may darken to brown when over-mature. Each spore is one-septate, ellipsoidal to elongate, and ends in either rounded or slightly pointed tips.

Asexual reproduction is common and takes place in pycnidial structures that are macroscopically indistinguishable from the ascostromata. These conidiomata produce no conidiophores; instead, pale- to medium-brown conidiogenous cells arise directly from the stromatic tissue. Each cell repeatedly buds off multicellular, brown conidia that resemble miniature cell clusters—ellipsoidal overall and initially smooth, though they can become warted or spiny in very old material.

Fossil history

The fossil history of Lichenostigma provides insights into its ancient origins and long-standing ecological relationships. Discoveries from European Paleogene amber have identified two fossil specimens of Lichenostigma associated with the crustose lichen genus Ochrolechia. These fossils date back approximately 34 million years, to the uppermost Eocene. The presence of Lichenostigma in these amber inclusions confirms that both the genus and its specialised parasitic association with Ochrolechia were already well-established during this period. The fossilised Lichenostigma specimens have conidiomata and ascomata (specialised structures to produce asexual and sexual spores, respectively) that are morphologically similar to those of modern species, demonstrating the evolutionary continuity of these lichenicolous fungi. This discovery not only pushes back the minimum age of the genus Lichenostigma but also provides calibration points for phylogenetic studies.

The identification of Lichenostigma in amber fossils marks a significant advancement in paleomycology, particularly regarding the fossil record of lichenicolous fungi. Prior to these findings, evidence of ancient lichen-associated microfungi was limited to more general and likely saprotrophic associations. The Lichenostigma fossils, however, represent the first concrete evidence of mycoparasitic relationships in the fossil record, highlighting the ecological importance of these interactions.

Species

, Species Fungorum (in the Catalogue of Life) accepts 30 species of Lichenostigma. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/8/81/2016-06-28_Lichenostigma_elongatum_Nav.-Ros._&_Hafellner_630390.jpg" caption="''[[Lichenostigma elongatum]]''"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/f0/2012-03-28_Lichenostigma_saxicola_K.Knudsen&_Kocourk_208668.jpg" caption="''[[Lichenostigma saxicola]]'' growing on bare granitic rock and neighbouring thalli of ''[[Aspicilia confusa]]'' and ''[[Lecidea laboriosa]]''."] ::

References

References

  1. A synopsis of Lichenostigma subgen. Lichenogramma (Arthoniales) with a key to the species, Vicent Calatayud1, Pere Navarro-Rosinés, Josef Hafellner, Mycological Research, Volume 106, Issue 10, October 2002, Pages 1230–1242, [http://www.sciencedirect.com/science/article/pii/S0953756208601781]
  2. (2006). "New records of lichens and lichenicolous fungi from Fuerteventura (Canary Islands), with descriptions of some new species". Cryptogamie Mycologie.
  3. (2002). "A synopsis of ''Lichenostigma'' subgen. ''Lichenogramma'' (Arthoniales) with a key to the species". Mycological Research.
  4. (2003). "A new ''Lichenostigma'' on vagrant ''Aspicilia'' species". The Lichenologist.
  5. (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)".
  6. "''Lichenostigma''".
  7. (2010). "''Lichenostigma rupicolae'' (Lichenotheliaceae), a new lichenicolous species growing on ''Pertusaria rupicola''". The Lichenologist.
  8. (1999). "''Lichenostigma cosmopolites'', a common lichenicolous fungus on ''Xanthoparmelia'' species". Mycotaxon.
  9. (2009). "''Lichenostigma anatolica'' sp. nov. (Ascomycota, Lichenotheliaceae) on a brown ''Acarospora'' from central Turkey". Mycotaxon.
  10. Hafellner, J.. (1982). "Studien über lichenicole Pilze und Flechten II. ''Lichenostigma maureri'' gen. et sp. nov., ein in den Ostalpen häufiger lichenicoler Pilz (Ascomycetes, Arthoniales)". Herzogia.
  11. Ihlen, Per G.. (2004). "A new species of ''Lichenostigma'' (Lichenotheliaceae, Arthoniales) from Scandinavia". The Lichenologist.
  12. (2019). "Crustose lichens with lichenicolous fungi from Paleogene amber". Scientific Reports.
  13. (2010). "A new ''Lichenostigma'' species (genus incertae sedis) from southern California". The Bryologist.
  14. (2013). "New and noteworthy lichen-forming and lichenicolous fungi". Acta Biologica Hungarica.
  15. (2017). "New and noteworthy lichen-forming and lichenicolous fungi 6". Acta Botanica Hungarica.
  16. (2004). "Lichen Flora of the Greater Sonoran Desert Region". Lichens Unlimited, Arizona State University.
  17. (1996). "''Lichenostigma elongata'' spec. nov. (Dothideales), a lichenicolous ascomycete on ''Lobothallia'' and ''Aspicilia'' species". Mycotaxon.
  18. Pegler, D.N.. (1983). "Agaric flora of the Lesser Antilles".
  19. (2009). "''Lichenostigma epirupestre'', a new lichenicolous species on ''Pertusaria'' from Spain". Mycotaxon.
  20. "Synonymy. Current Name: ''Lichenostigma'' Hafellner, Herzogia 6(1-2): 301 (1983)". [[Species Fungorum]].
  21. (2011). "Two new species of ''Lichenostigma'' (Lichenotheliaceae) from Iran". Willdenowia.
  22. (2007). "''Lichenostigma svandae'', a new lichenicolous fungus on ''Acarospora cervina''". The Lichenologist.
  23. (2020). "Outline of Fungi and fungus-like taxa". Mycosphere.

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arthoniomycetesascomycota-generalichenicolous-fungitaxa-named-by-josef-hafellnertaxa-described-in-1983