Biology:Graphis scripta
| Graphis scripta | |
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| Graphis scripta (lirellae) | |
Scientific classification 
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| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Graphidales |
| Family: | Graphidaceae |
| Genus: | Graphis |
| Species: | G. scripta
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| Binomial name | |
| Graphis scripta (L.) Ach. (1809)
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| Synonyms[2] | |
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Graphis scripta is a crustose lichen in the family Graphidaceae.[3] It is commonly called script lichen, secret writing lichen, or similar names, because its growth pattern makes it looks like writing.[4][5] Stigmidium microspilum and Arthonia graphidicola are associated lichenicolous fungi.[6] It is variable with either curved or stellate apothecia. The margins are carbonaceous and raised, without furrows. Mature ascospores are without colour, but become brown with age.[5]
Taxonomy
The lichen was formally described by Carl Linnaeus in 1753 as Lichen scriptus.[7] Erik Acharius later transferred the epithet to the genus Graphis.[8][2] In Acharius's treatment, the name was placed in synonymy with 30 other available names, and in 1923 Alexander Zahlbruckner adopted an even broader circumscription, listing over 100 synonyms under Graphis scripta.[9] Graphis is a predominantly tropical genus, and G. scripta is its type species and among the best-known members of the group.[10] Graphis is by far the largest genus in the family Graphidaceae; a world-wide key recognised 330 accepted species and listed a further 205 epithets as synonyms.[11]
In that treatment, the authors noted that the extratropical G. scripta complex remained unresolved, and suggested that G. scripta may represent a collective taxon.[11] Although some floras have generally treated it as a single, stable species, it shows substantial morphological variation, and more than 100 forms and varieties have been described within it.[10] Because the complex lacks distinctive secondary chemistry and has few measurable [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], attempts to divide it have mainly relied on apothecium and ascospore morphology.[9]
On the basis of apothecium features, Gerhard Neuwirth and André Aptroot recognised four species within the complex in Europe: G. scripta (apothecia remaining closed), G. macrocarpa (open, brownish discs), G. pulverulenta (open, white-[[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] discs), and G. betulina (with a conspicuous, thick [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]). They reported that these taxa can occur together and may even grow on the same tree, supporting the interpretation that at least some of the distinguishing characters are genetically fixed rather than simple substrate-driven variation.[10] However, a later molecular study sampling four genetic markers found six to seven distinct lineages within the G. scripta complex, and these did not correspond to the morphospecies recognised from apothecium morphology. The authors therefore concluded that a formal taxonomic revision will require broader sampling and the evaluation of additional [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] that can diagnose the genetically distinct clades.[9] Because no original Linnaean specimen is known to survive, the application of the name has been tied to a published illustration (lectotype) and stabilised with a later Swedish specimen (epitype).[10]
Description
The thallus (the main lichen body) is smooth or only slightly uneven, and is usually whitish green to green-grey, sometimes with a yellowish tinge. The apothecia (spore-producing structures) are typically elongate and script-like, either unbranched or branched, measuring about 5–25 mm long and 1–2 mm wide. Their outer rim (the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) is black and not furrowed, while the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is narrow and breaks through the surface to become exposed even in dry conditions; it is often dusted with a faint whitish [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]].[6] In most species of Graphis, the disc is concealed when dry, but a small number of species – including G. scripta and close relatives – can have the disc exposed even in dry conditions. Within the genus, a thin whitish pruina on the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] or disc is generally treated as a species-level character.[11]
The ascospores are 25–70 × 6–10 μm, spindle- to cylinder-shaped, and divided by 5–15 cross-walls (septa). Pycnidia are rare; when present, they produce very small conidia about 2–5 × about 1 μm. No lichen substances have been detected in this species using thin-layer chromatography.[6]
See also
- List of lichens named by Carl Linnaeus
References
- ↑ NatureServe. "Graphis scripta" (in en). Arlington, Virginia. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.126846/.
- ↑ 2.0 2.1 "GSD Species Synonymy. Current Name: Graphis scripta (L.) Ach., K. Vetensk-Acad. Nya Handl. 30(3): 145 (1809)". Species Fungorum. https://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=386168.
- ↑ "Graphis scripta (L.) Ach.". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/3H9TZ.
- ↑ The Deeper Teachings of Plant Life, Hugh Macmillan
- ↑ 5.0 5.1 Graphis scripta, Holton Lee, October 2012, Dorset Nature
- ↑ 6.0 6.1 6.2 Aptroot, A.; Weerakoon, G.; Cannon, P.; Coppins, B.; Sanderson, N.; Simkin, J. (2023). Ostropales: Graphidaceae, including the genera Allographa, Clandestinotrema, Crutarndina, Diploschistes, Fissurina, Graphis, Leucodecton, Phaeographis, Schizotrema, Thelotrema and Topeliopsis. Revisions of British and Irish Lichens. 36. p. 12. https://britishlichensociety.org.uk/sites/default/files/Graphidaceae.pdf.
- ↑ Linnaeus, Carl (1753) (in la). Species plantarum. 2. Stockholm: Impensis Laurentii Salvii. p. 1140. https://www.biodiversitylibrary.org/page/359161.
- ↑ Acharius, E. (1809). "Förteckning pa de i Sverige växande arter af Lafvarnes famille" (in la). Kongliga Vetenskaps Academiens Nya Handlingar 30: 145–169 [145].
- ↑ 9.0 9.1 9.2 Kraichak, Ekaphan; Lücking, Robert; Aptroot, Andre; Beck, Andreas; Dornes, Patrick; John, Volker; Lendemer, James C.; Nelsen, Matthew P. et al. (2015). "Hidden diversity in the morphologically variable script lichen (Graphis scripta) complex (Ascomycota, Ostropales, Graphidaceae)". Organisms Diversity & Evolution 15: 447–458. doi:10.1007/s13127-015-0219-5.
- ↑ 10.0 10.1 10.2 10.3 Neuwirth, Gerhard; Aptroot, André (2011). "Recognition of four morphologically distinct species in the Graphis scripta complex in Europe". Herzogia 24 (2): 207–230.
- ↑ 11.0 11.1 11.2 Lücking, Robert; Archer, Alan W.; Aptroot, André (2009). "A world-wide key to the genus Graphis (Ostropales: Graphidaceae)". The Lichenologist 41 (4): 363–452. doi:10.1017/S0024282909008305.
Wikidata ☰ Q113152 entry
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