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Diorygma

{{Short description|Genus of lichens}}

{{Use dmy dates|date=June 2025}}

{{Use Oxford spelling|date=June 2025}}

{{Automatic taxobox

| image = Diorygma antillarum - Flickr - pellaea.jpg

| image_caption = Diorygma antillarum found in Fakahatchee Strand Preserve State Park, Florida

| taxon = Diorygma

| authority = Eschw. (1824)

| type_species = Diorygma tinctorium

| type_species_authority = Eschw. (1824)

| subdivision_ranks = Species

| subdivision = See text

| synonyms_ref =

| synonyms = *Cyclographina {{au|D.D.Awasthi (1979)}}

}}

Diorygma is a genus of lichen-forming fungi in the family Graphidaceae. The genus was circumscribed by Franz Gerhard Eschweiler in 1824. Species of the genus are widely distributed in tropical and subtropical regions of the world. These lichens form paint-like crusts on bark and rock that range from chalky white to light green, with elongated, pencil-like slits containing their spores that may flex and branch across the surface. The genus was established in 1824 for tropical script lichens with large, many-celled spores, but molecular studies in the 2000s and 2010s expanded it significantly by transferring species from other genera and revealing new diversity.

Taxonomy

The name Diorygma was coined by Franz Gerhard Eschweiler in 1824 for a group of neotropical script lichens in the family Graphidaceae that have large, many-celled ({{lichengloss|muriform}}) spores and a thin, naked hymenium. Elias Fries accepted the genus in 1825—likening it to what is now Arthonia—but made no additional combinations. Eschweiler himself broadened the concept in 1833 by adding several species that subsequent work has reassigned to Fissurina and Platythecium. Towards the end of the nineteenth century, Johannes Müller Argoviensis erected the genus Graphina for {{lichengloss|muriform}}-spored taxa, retaining a handful of Diorygma species within his sections Platygraphina and Platygrammina, thereby narrowing the scope of Eschweiler's original taxon.{{sfn|Kalb|Staiger|Elix|2004|page=134}}

Interest in the group revived in the twentieth century. Dharani Dhar Awasthi and Mamta Joshi, while revising Helminthocarpon in 1979, recognised that these lirellate lichens formed a discrete lineage, but instead of resurrecting Eschweiler's name they introduced Cyclographina. In a comprehensive monograph of 2002, Bettina Staiger restored Diorygma for this assemblage and, on the basis of its rather unusual tissue organisation, suggested that it might fall outside the core Graphidaceae. Subsequent molecular analyses have confirmed that Diorygma does indeed belong within that family and have expanded its limits to include species with either single-spored, muriform asci or with spores divided only by transverse walls.{{sfn|Kalb|Staiger|Elix|2004|page=134}}

Description

Species of Diorygma form a crustose (tightly adherent, paint-like) thallus that ranges in hue from chalky white or cream to light olive-grey or green. The surface is generally dull and may be uneven, slightly wrinkled, or minutely warted; fine cracks are common. Unlike many other script lichens, the thallus lacks special powdery propagules (soralia or isidia). A true outer "skin" ({{lichengloss|pseudocortex}}) is poorly developed or absent, while the interior medulla is white and often riddled with conspicuous crystal deposits. The embedded partner alga is Trentepohlia, a filamentous green alga that imparts a faint orange tinge when exposed.{{sfn|Kalb|Staiger|Elix|2004|page=141}}

The sexual fruit-bodies are {{lichengloss|lirellae}}—elongate, pencil-like slits that may flex and branch across the thallus. Their margins can be thick and swollen or remain almost flush with the surface, and the exposed {{lichengloss|disc}} is usually brown, sometimes dusted with a whitish or yellowish bloom ({{lichengloss|pruina}}). Internally, the lateral wall ({{lichengloss|exciple}}) may be pale or blackened ("{{lichengloss|carbonised}}") and often shows fine striations produced by repeated regrowth events. The hymenium—the spore-producing layer—is clear and oil-free but stains bluish-violet in iodine at its upper and outer portions. At its roof lies a tangle of gelatinous, net-like paraphyses that carry nodular tips and brown or colourless {{lichengloss|granules}}. Club-shaped asci have the so-called "Graphis-type" apex with a thickened inner cap, and they bear one to eight colourless ascospores. These spores are oblong with rounded ends, occasionally spindle-shaped, and show transverse walls (sometimes with additional vertical walls to give a brick-like, {{lichengloss|muriform}} pattern); they measure roughly 15–250 × 5–60 μm and may turn blue-violet in iodine.{{sfn|Kalb|Staiger|Elix|2004|page=141}}

Asexual reproduction is rare and takes place in tiny pycnidia embedded in wart-like swellings about 0.1 mm across. These structures release minute, sausage-shaped to rod-shaped conidia 3.5–6 × 1–1.5 μm. Chemically, most species contain compounds of the norstictic or stictic acid families, while others produce protocetraric-series substances—secondary metabolites that can aid in species identification through chemical spot tests and thin-layer chromatography.{{sfn|Kalb|Staiger|Elix|2004|page=141}}

Species

{{As of|2025|June}}, Species Fungorum accepts 80 species of Diorygma.

File:Graphina (10.3897-mycokeys.25.13154) Figure 1D.jpg of Diorygma isabellinum]]

File:Diorygma poitaei - Flickr - pellaea (2).jpg

References

{{Reflist|refs=

{{cite journal |last1=Aptroot |first1=André |last2=Feuerstein |first2=Shirley |year=2020 |title=New Graphidaceae from South and Central Brazil |journal=Archive for Lichenology |volume=16 |pages=1–10 |url=http://www.fschumm.de/Archive/Vol16_Aptroot_&_Feuerstein_Graphidaceae_S_Brazil.pdf}}

{{cite journal |last1=Aptroot |first1=André |last2=Lücking |first2=Robert |last3=Cáceres |first3=Marcela Eugenia da Silva |title=New species and records of Graphidaceae and Gomphillaceae (lichenized fungi) from Brazil |journal=Plant and Fungal Systematics |volume=68 |issue=2 |year=2023 |doi=10.35535/pfsyst-2023-0010 |doi-access=free |pages=249–261}}

{{cite journal |last1=Archer |first1=A.W. |last2=Elix |first2=J.A. |year=2008 |title=Three new species in the Australian Graphidaceae (lichenized Ascomycota) |journal=Australasian Lichenology |volume=63 |pages=26–29}}

{{cite journal |last1=Archer |first1=A.W. |last2=Elix |first2=J.A. |year=2017 |title=A new species of Diorygma (Graphidaceae, lichenized Ascomycota) from Australia containing neotricone |journal=Australasian Lichenology |volume=81 |pages=93–95}}

{{cite book |last1=Cáceres |first1=M.E.S. |year=2007 |title=Corticolous crustose and microfoliose lichens of northeastern Brazil |series=Libri Botanici |volume=22 |page=67}}

{{cite web |author=Source dataset. Species Fungorum Plus: Species Fungorum for CoL+ |title=Diorygma |url=https://www.catalogueoflife.org/data/taxon/62R4N |work=Catalog of Life Version 2021-12-18 |access-date=17 June 2025}}

{{cite journal |last1=de Lima |first1=Edvaneide Leandro |last2=Maia |first2=Leonor Costa |last3=Aptroot |first3=André |last4=da Silva Cáceres |first4=Marcela Eugenia |title=New lichen species from Vale do Catimbau, Pernambuco, Brazil |journal=The Bryologist |volume=116 |issue=4 |year=2013 |doi=10.1639/0007-2745-116.4.327 |pages=327–329}}

{{cite journal |last1=de Lima |first1=Edvaneide Leandro |last2=Maia |first2=Leonor Costa |last3=Barroso Martins |first3=Mônica Cristina |last4=da Silva |first4=Nicácio Lima |last5=Lücking |first5=Robert |last6=da Silva Cáceres |first6=Marcela Eugenia |title=Five new species of Graphidaceae from the Brazilian Northeast, with notes on Diorygma alagoense |journal=The Bryologist |volume=122 |issue=3 |year=2019 |doi=10.1639/0007-2745-122.3.414 |pages=414–422}}

{{cite book |last=Eschweiler |first=FG. |title=Systema Lichenum, Genera Exhibens rite distincta, Pluribus Novis Adaucta |publisher=J. L. Schrag |year=1824 |pages=13, 24 |language=la}}

{{cite journal |last1=Feuerstein |first1=Shirley Cunha |last2=Cunha-Dias |first2=Iane Paula Rego |last3=Aptroot | first3=André |last4=Eliasaro |first4=Sionara |last5=Cáceres |first5=Marcela Eugenia da Silva |title=Three new Diorygma (Graphidaceae) species from Brazil, with a revised world key |journal=The Lichenologist |volume=46 |issue=6 |year=2014 |doi=10.1017/s002428291400036x |pages=753–761}}

{{cite journal |last1=Joshi |first1=Santosh |last2=Jayalal |first2=Udeni |last3=Oh |first3=Soon-Ok |last4=Koh |first4=Young Jin |last5=Nguyen |first5=Thi Thuy |last6=Dzung |first6=Nguyen Anh |last7=Hur |first7=Jae-Seoun |title=New species and new records in the family Graphidaceae (Ascomycota: Ostropales) from Vietnam |journal=The Lichenologist |volume=45 |issue=5 |year=2013 | doi=10.1017/s002428291300025x |pages=599–609}}

{{cite journal |last1=Kalb |first1=K. |year=2020 |title=New or otherwise interesting lichens. VII, including a world key to the lichen genus Heiomasia |journal=Archive for Lichenology |volume=15 |pages=1–18}}

{{cite journal |last1=Li |first1=Jian |last2=Jia |first2=Ze-Feng |title=Diorygma fuscum sp. nov. from China |journal=Mycotaxon |volume=131 |issue=3 |year=2016 |doi=10.5248/131.717 |pages=717–721 |doi-access=free}}

{{cite journal |last1=Makhija |first1=U. |last2=Chitale |first2=G. |last3=Sharma |first3=B. |year=2009 |title=New species and new records of Diorygma (Graphidaceae) from India: species with convergent exciples |journal=Mycotaxon |volume=109 |pages=379–392 |doi=10.5248/109.379 |doi-access=free}}

{{cite journal |last1=Mohabe |first1=S. |last2=Nayaka |first2=S. |last3=Reddy |first3=A.M. |last4=Anjali |first4=B.D. |year=2015 |title=Diorygma kurnoolensis (Graphidaceae), a new saxicolous lichen species from Andhra Pradesh, India |journal=Geophytology |volume=45 |issue=1 |pages=47–50}}

{{cite journal |last1=Papong |first1=Khwanruan Butsatorn |last2=Lücking |first2=Robert |last3=Kraichak |first3=Ekaphan |last4=Parnmen |first4=Sittiporn |last5=Konrat |first5=Matt Von |last6=Lumbsch |first6=H. Thorsten |title=Twenty-three new species in the lichen family Graphidaceae from New Caledonia (Ostropales, Ascomycota) |journal=Phytotaxa |volume=189 |issue=1 |year=2014 |doi=10.11646/phytotaxa.189.1.15 |pages=204–231}}

{{cite journal |last1=Plata |first1=Eimy Rivas |last2=Lücking |first2=Robert |title=High diversity of Graphidaceae (lichenized Ascomycota: Ostropales) in Amazonian Perú |journal=Fungal Diversity |volume=58 |issue=1 |year=2012 |doi=10.1007/s13225-012-0172-y |pages=13–32}}

{{cite journal |last1=Sharma |first1=B. |last2=Makhija |first2=U. |title=Four new species in the lichen genus Diorygma |journal=Mycotaxon |year=2009 |volume=107 |pages=87–94 |doi=10.5248/107.87 |url=http://www.cybertruffle.org.uk/cyberliber/59575/0107/0087.htm |doi-access=free}}

{{cite journal |last1=Sharma |first1=B.O. |last2=Makhija |first2=U. |year=2009 |title=New species and new reports of Diorygma (lichenized Ascomycotina, Graphidaceae) from India |journal=Mycotaxon |volume=109 |pages=209–217|doi=10.5248/109.209 |doi-access=free }}

{{cite journal |last1=Sharma |first1=B.O. |last2=Khadilkar |first2=P. |year=2012 |title=Four new species of Diorygma from India |journal=Mycotaxon |volume=119 |pages=1–10|doi=10.5248/119.1 |doi-access=free }}

{{cite journal |last=Sipman |first=Harrie J.M. |title=New species of Graphidaceae from the Neotropics and Southeast Asia |journal=Phytotaxa |volume=189 |issue=1 |year=2014 |doi=10.11646/phytotaxa.189.1.21 |pages=289–311 |doi-access=free}}

{{cite journal |last=Sipman |first=H.J.M. |year=2018 |title=Diorygma upretii spec. nov., a poleotolerant lichen in the tropics |journal=Cryptogam Biodiversity and Assessment |volume=Special volume (2018 |pages=1–5}}

{{cite web |title=Synonymy. Current Name: Diorygma Eschw., Syst. Lich.: 25 (1824) |url=http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=1593 |publisher=Species Fungorum |access-date=30 June 2022}}

{{cite journal |last1=Sutjaritturakan |first1=Jutarat |last2=Saipunkaew |first2=Wanaruk |last3=Boonpragob |first3=Kansri |last4=Kalb |first4=Klaus |year=2014 |title=New species of Graphidaceae (Ostropales) Lecanoromycetes) from southern Thailand |journal=Phytotaxa |volume=189 |issue=1 |pages=312–324 |doi=10.11646/PHYTOTAXA.189.1.22}}

}}

=Cited literature=

  • {{cite journal |last1=Kalb |first1=K. |last2=Staiger |first2=B. |last3=Elix |first3=J.A. |year=2004 |title=A monograph of the lichen genus Diorygma – a first attempt |journal=Symbolae Botanicae Upsalienses |volume=34 |issue=1 |pages=133–181}}

{{Taxonbar|from=Q5279571}}

Category:Graphidales genera

Category:Lichen genera

Category:Taxa named by Franz Gerhard Eschweiler

Category:Taxa described in 1824