Cresponea

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Genus of lichens

title: "Cresponea" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["opegraphaceae", "arthoniomycetes-genera", "lichen-genera", "taxa-described-in-1993"] description: "Genus of lichens" topic_path: "general/opegraphaceae" source: "https://en.wikipedia.org/wiki/Cresponea" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Genus of lichens ::

| image = Cresponea chloroconia 1136166.jpg | image_caption = Cresponea chloroconia | taxon = Cresponea | authority = Egea & Torrente (1993) | type_species = Cresponea premnea | type_species_authority = (Ach.) Egea & Torrente (1993) | subdivision_ranks = Species | subdivision =

Cresponea is a genus of lichens in the family Opegraphaceae. The genus, circumscribed in 1993, contains species that were formerly classified in Lecanactis. Cresponea is widely distributed, but most species are found in tropical and subtropical regions. The genus is named in honor of the Spanish lichenologist Ana Crespo.

Description

Cresponea spreads as a thin, paint-like crust that merges with the surface of bark or, less often, rock. The thallus can be smooth or cracked into an irregular mosaic, and on rare occasions it breaks into tiny, discrete . Colours range from chalk-white through pale grey to a muted green; some specimens show a narrow, dark brown margin where the fungal threads alone grow out beyond the . Because there is no separate , the fungal tissue lies directly over the , usually the filamentous green alga genus Trentepohlia, which gives a faint orange tint when the surface is scratched. The lichen never produces isidia or soralia, so it relies on its sexual and asexual fruit bodies for dispersal.

The sexual structures are small, button-like apothecia that sit on the thallus with a pinched base. They lack a rim of thallus tissue, instead showing a glossy, often crenulated rim (the ) that is conspicuously dark brown to black and remains free of the powdery bloom that coats many related genera. The starts flat, may become gently domed, and is dusted with a fine white or bluish , especially in young apothecia. Inside, the clear hymenium stains blue or reddish in iodine and houses slender filaments whose club-shaped tips carry a dark brown cap; together these caps form a granular that turns yellow in potassium hydroxide solution. Each ascus releases eight long, spindle-shaped ascospores divided by three to nineteen cross-walls (septa); the walls are thick, and the spores stay colourless. Asexual reproduction occurs in tiny pycnidia embedded in the crust; these produce short, rod-shaped conidia. Most species show no detectable lichen products in chemical tests.

Ecology

Generally epiphytic, Cresponea lichen prefer mature, humid woodlands and are sometimes used as an indicator of old-growth conditions, though a few species tolerate rock surfaces in sheltered sites.

Species

, Species Fungorum (in the Catalogue of Life) accepts 23 species of Cresponea.

References

References

  1. "IAL - Acharius Medallists".
  2. (2021). "Saxicolous lichens in the semi-arid caatinga in Brazil show substratum shifts". Cryptogamie, Mycologie.
  3. (2022). "New species of lichenized fungi from Brazil, with a record report of 492 species in a small area of the Amazon Forest". The Bryologist.
  4. (2014). "Species of Arthoniales from the Amazon, Rondônia, Brazil". The Lichenologist.
  5. (2023). "Arthoniales: Roccellaceae [revision 1], including the genera ''Cresponea'', ''Dendrographa'', ''Dirina'', ''Enterographa'', ''Gyrographa'', ''Lecanactis'', ''Ocellomma'', ''Pseudoschismatomma'', ''Psoronactis'', ''Roccella'', ''Schismatomma'' and ''Syncesia''".
  6. "''Cresponea''".
  7. (1993). "''Cresponea'', a new genus of lichenized fungi in the order Arthoniales (Ascomycotina)". Mycotaxon.
  8. Elix, J.A.. (2007). "Four new crustose lichens (lichenized Ascomycota) from Australia". Australasian Lichenology.
  9. Kantvilas, Gintaras. (2020). "Contributions to the lichen genus ''Cresponea'' (Roccellaceae)". The Lichenologist.
  10. (2013). "New species of Arthoniales from NE Brazil". The Lichenologist.

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opegraphaceaearthoniomycetes-generalichen-generataxa-described-in-1993