{{Short description|Genus of lichen-forming fungi}} {{Use dmy dates|date=June 2025}} {{Use Oxford spelling|date=June 2025}} {{Automatic taxobox | image = | taxon = Sarcographina | authority = [[Müll.Arg.]] (1887) | type_species = Sarcographina cyclospora | type_species_authority = Müll.Arg. (1887) | subdivision_ranks = Species | subdivision = ''[[Sarcographina contortuplicata|S. contortuplicata]]''<br /> ''[[Sarcographina cyclospora|S. cyclospora]]''<br /> ''[[Sarcographina farinulenta|S. farinulenta]]''<br /> ''[[Sarcographina heterospora|S. heterospora]]''<br /> ''[[Sarcographina maculata|S. maculata]]''<br /> ''[[Sarcographina sandwicensis|S. sandwicensis]]'' }}
'''''Sarcographina''''' is a [[genus]] of [[script lichen]]s in the family [[Graphidaceae]].<ref name="CoL"/> It comprises six species.<ref name="Wijayawardene et al. 2022"/> Established in 1887 by the Swiss lichenologist [[Johannes Müller Argoviensis]], these [[corticolous lichen|bark-dwelling lichens]] are distinguished by their star-burst colonies of short, curved fruiting structures with jet-black borders and [[ascospore]]s that [[staining|stain]] violet when treated with [[iodine]]. Found in humid [[tropical]] and warm [[temperate]] forests worldwide, they serve as [[bioindicator|indicators]] of [[disturbance (ecology)|undisturbed]] woodland habitats due to their sensitivity to [[canopy (botany)|canopy]] opening and drought.
==Taxonomy==
The genus was [[circumscription (taxonomy)|circumscribed]] by the Swiss lichenologist [[Johannes Müller Argoviensis]] in 1887, with ''[[Sarcographina cyclospora]]'' assigned as the [[type species]]. In his original description, Müller characterised ''Sarcographina'' by its crustaceous [[thallus]] and chrome-coloured {{lichengloss|photobiont}}, with {{lichengloss|lirellae}} densely aggregated in spot-like {{lichengloss|stromata}} that are immersed in the thallus surface. He distinguished the genus from ''[[Sarcographa]]'' by noting that the lirellae are arranged in dense clusters rather than radiating patterns, and described the [[perithecium]] as having its own distinct boundary that is brownish-black and internally indistinct. Müller noted the linear [[ascus|asci]] contain simple [[paraphyses]] and both dark and pale [[ascospore]]s. The genus name reflects its close relationship to ''Sarcographa'', with the suffix "-ina" indicating a diminutive or related form.<ref name="Müller 1887"/>
==Description==
''Sarcographina'' forms a smooth, chalk-white to pale grey crust ([[thallus]]) that grows flush with the bark and lacks a true {{lichengloss|cortex}}. Its fruit bodies are arranged in neat, star-burst colonies of short, curved {{lichengloss|lirellae}} whose walls are jet-black and wholly {{lichengloss|carbonised}}. A colourless to pale brown {{lichengloss|excipulum}} lines each slit, overhung by a yellow-brown {{lichengloss|epithecium}} often dusted with a fine {{lichengloss|pruina}}. The [[hymenium]] is densely {{lichengloss|inspersed}} with oil droplets, and the thin-walled ''Graphis''-type [[ascus|asci]] contain eight hyaline [[ascospore]]s that are relatively small (roughly 15–35 × 5–10 [[μm]]), transversely 3–9-septate, and [[staining|stain]] deep violet in iodine (I+). Many species synthesise the [[ultraviolet]]-fluorescent pigment [[lichexanthone]], together with traces of [[norstictic acid]] or [[stictic acid]], giving the {{lichengloss|discs}} a dull [[ochre]] tint in reflected light and a bright yellow glow under long-wave ultraviolet.<ref name="Lücking & Rivas Plata 2008"/>
The combination of [[rosette (botany)|rosette]]-forming lirellae, a strongly inspersed hymenium and I+ (violet), small-segmented spores separates ''Sarcographina'' from its sister genus ''[[Sarcographa]]'', whose hymenium is clear and whose larger spores remain iodine-negative. Other script lichens with carbonised margins—such as ''[[Glyphis (lichen)|Glyphis]]'', ''[[Hemithecium]]'' and ''[[Redingeria]]''—lack the star-burst architecture, the persistent inspersion or the lichexanthone fluorescence that diagnose ''Sarcographina''.<ref name="Lücking & Rivas Plata 2008"/>
==Ecology==
The genus has a [[pantropical]] to warm-[[temperate]] distribution, with records from lowland [[Amazonian rainforest]], West-Central African evergreen stands, Indo-Malayan [[dipterocarp]] forest and humid coastal woodlands of [[Queensland]]. All known species are [[corticolous lichen|corticolous]], [[colonisation (biology)|colonising]] shaded [[trunk (botany)|boles]] and large branches where high ambient humidity prevails; some taxa, particularly those rich in [[lichexanthone]], also tolerate intermittent [[sunfleck]]s on [[mangrove]] trunks and creek bank trees. Field surveys show that populations decline rapidly after [[canopy (botany)|canopy]] opening or prolonged [[desiccation]], so the presence of ''Sarcographina'' is a practical [[bioindicator|indicator]] of long-established, moisture-rich [[woodland]] habitat.<ref name="Lücking & Rivas Plata 2008"/>
==Species== [[Species Fungorum]] (in the [[Catalogue of Life]]) accepts six species of ''Sarcographina'':<ref name="CoL"/> * ''[[Sarcographina contortuplicata]]'' {{au|Müll.Arg. (1891)}}<ref name="Müller 1891"/> * ''[[Sarcographina cyclospora]]'' {{au|Müll.Arg. (1887)}}<ref name="Müller 1887"/> * ''[[Sarcographina farinulenta]]'' {{au|Zahlbr. (1928)}}<ref name="Zahlbruckner 1928"/> * ''[[Sarcographina heterospora]]'' {{au|(Nyl.) Z.F.Jia & Lücking (2017)}}<ref name="Jia & Lücking 2017"/> * ''[[Sarcographina maculata]]'' {{au|Kr.P.Singh & G.P.Sinha (1994)}}<ref name="Singh & Sinha 1994"/> * ''[[Sarcographina sandwicensis]]'' {{au|Zahlbr. (1912)}}<ref name="Zahlbruckner 1912"/>
==References== {{Reflist|colwidth=30em|refs=
<ref name="CoL">{{Catalogue of Life |id=63RPX |title=''Sarcographina'' |access-date=22 June 2025}}</ref>
<ref name="Jia & Lücking 2017">{{cite journal |last1=Jia |first1=Ze-Feng |last2=Lücking |first2=Robert |title=Resolving the genus ''Phaeographina'' Müll. Arg. in China |journal=MycoKeys |issue=21 |year=2017 |doi=10.3897/mycokeys.21.11986 |doi-access=free |pages=13–32}}</ref>
<ref name="Lücking & Rivas Plata 2008">{{cite journal |last1=Lücking |first1=Robert |last2=Rivas Plata |first2=Eimy |year=2008 |title=Clave y guía ilustrada para géneros de Graphidaceae |trans-title=Key and illustrated guide to genera of Graphidaceae |journal=GLALIA |language=es |volume=1 |issue=1 |pages=1–39 |url=https://archive.org/details/2008_Glalia_1_1}}</ref>
<ref name="Müller 1887">{{cite journal |last=Müller |first=J. |year=1887 |title=Lichenologische Beiträge XXVI |trans-title=Lichenological contributions XXVI |journal=Flora (Regensburg) |volume=70 |issue=26/27 |pages=423–429 [425] |language=la |url=https://www.biodiversitylibrary.org/page/70321}}</ref>
<ref name="Müller 1891">{{cite journal |last=Müller |first=J. |year=1891 |title=Lichenes Tonkinensis a cl. B. Balansa lecti |trans-title=Lichens of Tonkin collected by the renowned B. Balansa |journal=Hedwigia |volume=30 |pages=181–189 |language=la}}</ref>
<ref name="Singh & Sinha 1994">{{cite book |last1=Singh |first1=K.P. |last2=Sinha |first2=G.P. |year=1994 |title=Lichen Flora of Nagaland |page=114}}</ref>
<ref name="Wijayawardene et al. 2022">{{cite journal |display-authors=6 |last1=Wijayawardene |first1=N.N. |last2=Hyde |first2=K.D. |last3=Dai |first3=D.Q. |last4=Sánchez-García |first4=M. |last5=Goto |first5=B.T. |last6=Saxena |first6=R.K. |last7=Erdoğdu |first7=M. |last8=Selçuk |first8=F. |last9=Rajeshkumar |first9=K.C. |last10=Aptroot |first10=A. |last11=Błaszkowski |first11=J. |last12=Boonyuen |first12=N. |last13=da Silva |first13=G. |last14=de Souza |first14=F.A. |last15=Dong |first15=W. |last16=Ertz |first16=D. |last17=Haelewaters |first17=D. |last18=Jones |first18=E.B. |last19=Karunarathna |first19=S.C. |last20=Kirk |first20=P.M. |last21=Kukwa |first21=M. |last22=Kumla |first22=J. |last23=Leontyev |first23=D.V. |last24=Lumbsch |first24=H.T. |last25=Maharachchikumbura |first25=S.S.N. |last26=Marguno |first26=F. |last27=Martínez-Rodríguez |first27=P. |last28=Mešić |first28=A. |last29=Monteiro |first29=J.S. |last30=Oehl |first30=F. |last31=Pawłowska |first31=J. |last32=Pem |first32=D. |last33=Pfliegler |first33=W.P. |last34=Phillips |first34=A.J.L. |last35=Pošta |first35=A. |last36=He |first36=M.Q. |last37=Li |first37=J.X. |last38=Raza |first38=M. |last39=Sruthi |first39=O.P. |last40=Suetrong |first40=S. |last41=Suwannarach |first41=N. |last42=Tedersoo |first42=L. |last43=Thiyagaraja |first43=V. |last44=Tibpromma |first44=S. |last45=Tkalčec |first45=Z. |last46=Tokarev |first46=Y.S. |last47=Wanasinghe |first47=D.N. |last48=Wijesundara |first48=D.S.A. |last49=Wimalaseana |first49=S.D.M.K. |last50=Madrid |first50=H. |last51=Zhang |first51=G.Q. |last52=Gao |first52=Y. |last53=Sánchez-Castro |first53=I. |last54=Tang |first54=L.Z. |last55=Stadler |first55=M. |last56=Yurkov |first56=A. |last57=Thines |first57=M. |year=2022 |title=Outline of Fungi and fungus-like taxa – 2021 |journal=Mycosphere |volume=13 |issue=1 |pages=53–453 [161] |doi=10.5943/mycosphere/13/1/2 |url=https://www.researchgate.net/publication/358798332|hdl=10481/76378 |hdl-access=free }}</ref>
<ref name="Zahlbruckner 1912">{{cite journal |last=Zahlbruckner |first=A. |year=1912 |title=Neue Flechten – VI |trans-title=New lichens – VI |journal=Annales Mycologici |volume=10 |issue=4 |pages=359–384 |language=la}}</ref>
<ref name="Zahlbruckner 1928">{{cite journal |last=Zahlbruckner |first=A. |year=1928 |title=Neue und ungenügend beschriebene javanische Flechten |trans-title=New and inadequately described Javanese lichens |journal=Annales de Cryptogamie Exotique |volume=1 |page=152 |language=de}}</ref>
}}
{{Taxonbar|from=Q21215982}}
[[Category:Graphidaceae]] [[Category:Lichen genera]] [[Category:Graphidales genera]] [[Category:Taxa described in 1887]] [[Category:Taxa named by Johannes Müller Argoviensis]]