# Graphis (lichen)

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Genus of lichen-forming fungi

Graphis Graphis scripta (lirellae) Scientific classification Kingdom: Fungi Division: Ascomycota Class: Lecanoromycetes Order: Graphidales Family: Graphidaceae Genus: Graphis Adans. (1763) Type species Graphis scripta (L.) Ach. (1809) Species List of Graphis (lichen) species Synonyms[1] Oxystoma Eschw. (1824) Fissurina Fée (1825) Aulacographa Leight. (1854) Diplolabia A.Massal. (1854) Dyplolabia A.Massal. (1854) Diplographis Kremp. ex A.Massal. (1860) Anomomorpha Nyl. ex Hue (1891) Digraphis Clem. (1909) Graphidomyces E.A.Thomas ex Cif. & Tomas. (1953)

***Graphis*** is a [genus](/source/Genus) of [lichen](/source/Lichen)-forming [fungi](/source/Fungi) in the family [Graphidaceae](/source/Graphidaceae).[2] Historically, *Graphis* was used as a broad category for species with colourless, transversely [septate](/source/Septum) ascospores within the Graphidaceae. However, with advances in genetic research, this classification has become more refined. As a result, species previously classified under *[Graphina](/source/Graphina)* have been re-assigned to *Allographa* or *Graphis*. The [species complex](/source/Species_complex) around *[Graphis scripta](/source/Graphis_scripta)* has also been recognised, leading to the identification of several new species, many of which may have been previously overlooked.[3]

## Taxonomy

The genus *Graphis* was introduced by the French naturalist [Michel Adanson](/source/Michel_Adanson) in 1763, in a brief protologue that framed these lichens in simple, field-visible terms. He characterised *Graphis* as a thin, creeping, powdery crust ([farinose](/source/Glossary_of_lichen_terms#farinose)) spreading like a film and marked by furrows that could be simple or branched, sometimes with the margins raised into low ridges; he also recorded small spherical bodies occupying the furrows. In the same entry he pointed readers to earlier illustrations by [Dillenius](/source/Dillenius).[4]

Early work on the lirellate Graphidaceae produced an unstable and contested set of generic names: during the 19th century, dozens of generic names were proposed for these "script lichens", and authors disagreed on which characters should define genera.[5][6] A widely adopted late-19th-century scheme was that of [Johannes Müller Argoviensis](/source/Johannes_M%C3%BCller_Argoviensis), who treated the non-[stromatic](/source/Stroma_(fungus)), lirellate taxa as four spore-defined genera—*Graphis* ([hyaline](/source/Hyaline), transversely [septate](/source/Septum)), *[Graphina](/source/Graphina)* (hyaline, [muriform](/source/Glossary_of_lichen_terms#muriform)), *[Phaeographis](/source/Phaeographis)* (grey-brown, transverse) and *[Phaeographina](/source/Phaeographina)* (grey-brown, muriform)—alongside several stromatic genera.[6] That framework was challenged by [Edvard Vainio](/source/Edvard_Vainio), who united the family in a single genus *Graphis* but retained comparable groupings at the [rank](/source/Taxonomic_rank) of [subgenus](/source/Subgenus), and it was later reinstated in a more traditional form by [Alexander Zahlbruckner](/source/Alexander_Zahlbruckner). Despite early criticism that the approach was artificial, these spore-based genera remained in common use well into the 20th century, until later revisions began to prioritise [ascoma](/source/Ascoma) anatomy over [ascospore](/source/Ascospore) septation in defining natural genera.[6][7][5]

The genus *Graphis* has been interpreted in both narrow and very broad ways. During the 19th and early 20th centuries, most classification in the lirellate Graphidaceae relied heavily on ascospore characters (especially spore colour and whether spores were only transversely septate or also muriform), which produced a set of "ascospore genera" used for many decades. That approach was increasingly regarded as artificial, because species that were otherwise very similar could be placed in different genera on ascospore septation alone. This problem was later framed in terms of "sporomorphs": look‑alike taxa separated mainly by spore type.[6]

Modern generic limits in Graphidaceae were reshaped by revisions that emphasised ascoma anatomy, especially the structure of the [lirellae](/source/Glossary_of_lichen_terms#lirellae) (the elongate, slit-like [fruiting bodies](/source/Fruiting_bodies)) and their [excipulum](/source/Glossary_of_lichen_terms#excipulum) (the ascoma wall). In the [circumscription](/source/Circumscription_(taxonomy)) followed by [Bettina Staiger](/source/Bettina_Staiger) (2002) and summarised by [Robert Lücking](/source/Robert_L%C3%BCcking) (2009), *Graphis* is characterised by lirellae with well-developed, typically darkened [labia](/source/Glossary_of_lichen_terms#labia) that usually conceal the [disc](/source/Glossary_of_lichen_terms#disc), an excipulum that is partly to completely [carbonised](/source/Glossary_of_lichen_terms#carbonised), a [hymenium](/source/Hymenium) that is usually not [inspersed](/source/Glossary_of_lichen_terms#inspersed), and hyaline ascospores that are iodine-positive (I+) and range from transversely septate to muriform. Under this concept, many species formerly treated in *Graphina* are included within *Graphis*, while other taxa once placed in *Graphis* in a broad sense have been reassigned to genera such as *[Acanthothecis](/source/Acanthothecis)*, *[Carbacanthographis](/source/Carbacanthographis)*, *[Diorygma](/source/Diorygma)*, *[Dyplolabia](/source/Dyplolabia)*, *[Fissurina](/source/Fissurina)*, *[Glyphis](/source/Glyphis_(lichen))* and *[Hemithecium](/source/Hemithecium)*.[6]

To evaluate which [phenotype](/source/Phenotype) characters help delimit species and species groups, Lücking assessed 313 accepted species using a large set of [morphological](/source/Morphology_(biology)), anatomical and chemical characters analysed with numerical ordination and phenotype-based [cladistic](/source/Cladistic) methods. A central finding was that the most informative character complex for recognising coherent groupings within *Graphis* is lirella morphology, especially how the lirellae emerge from the thallus and what kind of [thalline margin](/source/Glossary_of_lichen_terms#thalline_margin) they retain. By contrast, several traits that have often been treated as primary "key characters" (for example labial striation, the degree of excipulum carbonisation, and patterns in chemistry) can vary widely among otherwise similar species and may shift repeatedly across the genus, so they are most reliable when interpreted alongside the overall lirella type rather than used in isolation.[6]

On this basis, Lücking outlined tentative species groups within *Graphis* defined mainly by lirella types, including the *G. scripta* group (about 90 species), *G. subserpentina* group (c. 20), *G. acharii* group (c. 60) and *G. striatula* group (c. 60), as well as smaller assemblages such as the *G. nuda*, *G. dussii*, *G. marginata* and *G. symplecta* groups; most currently accepted species could be assigned to one of these clusters. The study also broadened the older "sporomorph" idea into a general "morph" framework for sets of otherwise similar species that differ chiefly in one character complex (for example differences in excipulum carbonisation, hymenial inspersion, ascospore features, or secondary chemistry). These groupings were explicitly presented as a practical, phenotype-based working hypothesis for identification and for targeting future [molecular](/source/Molecular_phylogenetics) sampling in a genus too large to be comprehensively sequenced at the time.[6]

## Description

*Graphis elegans*

Genus *Graphis* includes [crustose lichens](/source/Crustose_lichen), which have a crust-like appearance that can range from being fully embedded in the substrate to sitting on the surface. The lichen's symbiotic partner, or [photobiont](/source/Glossary_of_lichen_terms#photobiont), is [green algae](/source/Green_algae) from the genus *[Trentepohlia](/source/Trentepohlia_(alga))*. The [apothecia](/source/Glossary_of_lichen_terms#apothecia) (fruiting bodies) of *Graphis* can also be immersed or superficial. These structures are typically elongated, resembling slits (referred to as [lirelliform](/source/Glossary_of_lichen_terms#lirelliform)), and can be [simple](/source/Glossary_of_lichen_terms#simple), branched, or star-shaped. The [disc](/source/Glossary_of_lichen_terms#disc) of the apothecium, where spores are released, often remains slit-like or closed. Unlike some lichens, *Graphis* lacks a [thalline exciple](/source/Glossary_of_lichen_terms#thalline_exciple), which is a rim of tissue derived from the lichen thallus surrounding the apothecium. Instead, it has a [true exciple](/source/Glossary_of_lichen_terms#true_exciple), which is usually black, opaque, and well-developed. This exciple is sometimes marked by longitudinal grooves.[3]

Inside the apothecium, the [hymenium](/source/Hymenium) (a spore-bearing layer) is colourless and does not react to [staining](/source/Staining) with [iodine](/source/Iodine) (I-). Beneath this layer, the [hypothecium](/source/Glossary_of_lichen_terms#hypothecium) can be either pale or dark, and it is relatively thin. The [hamathecium](/source/Glossary_of_lichen_terms#hamathecium), which supports the developing spores, consists of unbranched filaments called [paraphyses](/source/Paraphyses). The spore-producing structures, the [asci](/source/Ascus), typically contain up to eight spores. These asci are club-shaped to slightly cylindrical and release their spores through an apical split. The spores themselves are divided by transverse walls ([septate](/source/Septum)) or have a [muriform](/source/Glossary_of_lichen_terms#muriform) structure (multiple divisions), and they turn violet when stained with iodine as they mature. Initially colourless, these spores may darken to brown if they become over-mature. *Graphis* also produces [conidia](/source/Conidia), which are asexual spores, within flask-shaped structures called [pycnidia](/source/Pycnidia). The conidia are usually cylindrical to ellipsoidal and remain colourless.[3]

Chemically, some species of *Graphis* contain compounds known as β-[orcinol](/source/Orcinol) depsidones. Additionally, older apothecia in certain species might react with [potassium hydroxide](/source/Potassium_hydroxide) solution (K+) to produce a purple colouration, indicating the presence of [anthraquinones](/source/Anthraquinone).[3]

*Graphis* can be distinguished from the genus *[Phaeographis](/source/Phaeographis)* by its colourless spores, which may become brown with age. Additionally, in the field, *Graphis* species may resemble *[Opegrapha](/source/Opegrapha)* species, but the latter can be differentiated by their distinctively structured asci and spore-bearing tissues.[3]

## Habitat and distribution

*Graphis* has a [cosmopolitan distribution](/source/Cosmopolitan_distribution), which includes most continents across the world.[8] This includes [Florida](/source/Florida) in North America.[9] Ecologically, *Graphis* lichens are mostly found [growing on bark](/source/Corticolous_lichen), though they are occasionally found [on rock](/source/Saxicolous_lichen). The genus is primarily distributed in [tropical](/source/Tropical) and [subtropical](/source/Subtropical) regions, with a few extending into [temperate](/source/Temperate) zones.[3]

## References

1. **[^](#cite_ref-urlMycoBank_1-0)** ["*Graphis* Adans. 1763"](http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=2131). *MycoBank*. International Mycological Association. Retrieved 2011-06-21.

1. **[^](#cite_ref-Wijayawardene_et_al._2020_2-0)** Wijayawardene, Nalin; Hyde, Kevin; Al-Ani, LKT; S, Dolatabadi; Stadler, Marc; Haelewaters, Danny; et al. (2020). ["Outline of Fungi and fungus-like taxa"](https://doi.org/10.5943%2Fmycosphere%2F11%2F1%2F8). *Mycosphere*. **11**: 1060–1456. [doi](/source/Doi_(identifier)):[10.5943/mycosphere/11/1/8](https://doi.org/10.5943%2Fmycosphere%2F11%2F1%2F8). [hdl](/source/Hdl_(identifier)):[10481/61998](https://hdl.handle.net/10481%2F61998).

1. ^ [***a***](#cite_ref-Aptroot_et_al._2023_3-0) [***b***](#cite_ref-Aptroot_et_al._2023_3-1) [***c***](#cite_ref-Aptroot_et_al._2023_3-2) [***d***](#cite_ref-Aptroot_et_al._2023_3-3) [***e***](#cite_ref-Aptroot_et_al._2023_3-4) [***f***](#cite_ref-Aptroot_et_al._2023_3-5) 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](https://britishlichensociety.org.uk/sites/default/files/Graphidaceae.pdf) (PDF). Revisions of British and Irish Lichens. Vol. 36. pp. 8–9.

1. **[^](#cite_ref-Adanson_1763_4-0)** Adanson, Michel (1763). [*Familles des plantes*](https://books.google.ca/books?id=3UZLzGwfahsC&vq=Graphis&pg=PA24-IA15#v=snippet&q=Graphis&f=false) (in French). Vol. 2. Paris: chez Vincent. p. 11.

1. ^ [***a***](#cite_ref-Staiger_2002_5-0) [***b***](#cite_ref-Staiger_2002_5-1) Staiger, B. (2002). *Die Flechtenfamilie Graphidaceae: Studien in Richtung einer natürlichen Gliederung* [*The lichen family Graphidaceae: studies towards a natural organization*]. Bibliotheca Lichenologica (in German). Vol. 85. Berlin/Stuttgart: J. Cramer. [ISBN](/source/ISBN_(identifier)) [978-3-443-58064-3](https://en.wikipedia.org/wiki/Special:BookSources/978-3-443-58064-3).

1. ^ [***a***](#cite_ref-Lücking_2009_6-0) [***b***](#cite_ref-Lücking_2009_6-1) [***c***](#cite_ref-Lücking_2009_6-2) [***d***](#cite_ref-Lücking_2009_6-3) [***e***](#cite_ref-Lücking_2009_6-4) [***f***](#cite_ref-Lücking_2009_6-5) [***g***](#cite_ref-Lücking_2009_6-6) Lücking, Robert (2009). "The taxonomy of the genus *Graphis* *sensu* Staiger (Ascomycota: Ostropales: Graphidaceae)". *The Lichenologist*. **41** (4): 319–362. [doi](/source/Doi_(identifier)):[10.1017/S0024282909008524](https://doi.org/10.1017%2FS0024282909008524).

1. **[^](#cite_ref-Wirth_&_Hale_1978_7-0)** Wirth, M.; Hale Jr., M.E. (1978). [*Morden-Smithsonian Expedition to Dominica: the lichens (Graphidaceae)*](https://repository.si.edu/server/api/core/bitstreams/71d93c12-ad4a-4a43-96b8-7779cb5ad43e/content). Smithsonian Contributions to Botany. Vol. 40. pp. 1–64.

1. **[^](#cite_ref-8)** ["*Graphis* Adans., 1763"](https://www.gbif.org/species/2602041). *www.gbif.org*. Retrieved 6 February 2023.

1. **[^](#cite_ref-9)** Seavey, Frederick; Seavey, Jean (2011). "The lichen genus Graphis (Graphidaceae) in Everglades National Park (Florida)". *The Bryologist*. **114** (4): 764–784. [doi](/source/Doi_(identifier)):[10.1639/0007-2745-114.4.764](https://doi.org/10.1639%2F0007-2745-114.4.764).

Taxon identifiers Graphis Wikidata: Q3740279 Wikispecies: Graphis (Graphidaceae) AusLichen: 30017667 CoL: 4QV4 EPPO: 1GRPSG FloraBase: 27467 GBIF: 2602041 iNaturalist: 117992 IndexFungorum: 2131 IRMNG: 1361721 MycoBank: 2131 NBN: NHMSYS0000079902 NCBI: 71599 NZOR: caaddd7c-772b-41ae-8858-a5bcc1ed56f6 Open Tree of Life: 163526 PLANTS: GRAPH2 SpeciesFungorum: 2131 Dyplolabia Wikidata: Q5319258 Wikispecies: Dyplolabia AusLichen: 30017481 CoL: 4925 EoL: 22872 FloraBase: 27460 GBIF: 2601855 iNaturalist: 462849 IndexFungorum: 1725 IRMNG: 1059188 MycoBank: 1725 NCBI: 297879 SpeciesFungorum: 1725 Diplographis Wikidata: Q64166187 GBIF: 7249753 IndexFungorum: 1612 IRMNG: 1073857 MycoBank: 1612 SpeciesFungorum: 1612

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Adapted from the Wikipedia article [Graphis (lichen)](https://en.wikipedia.org/wiki/Graphis_(lichen)) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Graphis_(lichen)?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.