{{Short description|Single-species fungal genus}} {{Use dmy dates|date=November 2025}} {{Use Oxford spelling|date=November 2025}} {{Speciesbox | image = Melaspileella proximella 1621259532.jpg | image_caption = ''Melaspileella proximella'' | grandparent_authority = D.Q.Dai & K.D.Hyde (2018) | parent_authority = (P.Karst.) Vain. (1921) | taxon = Melaspileella proximella | authority = (Nyl.) Ertz & Diederich (2015) | synonyms_ref = <ref name="Species Fungorum synonymy"/><ref name="MycoBank"/><ref name="Olariaga"/> | synonyms = {{Collapsible list|bullets=on |''Arthonia proximella'' {{au|Nyl. (1861)}} |''Catillaria proximella'' {{au|(Nyl.) Th.Fr. (1861)}} |''Buellia proximella'' {{au|(Nyl.) Rabenh. (1870)}} |''Caldesia proximella'' {{au|(Nyl.) Trevis. (1871)}} |''Coniangium proximellum'' {{au|(Nyl.) Hellb. (1871)}} |''Melaspilea proximella'' {{au|(Nyl.) Nyl. (1873)}} |''Celidium proximellum'' {{au|(Nyl.) P.Karst. (1885)}} }} }}
'''''Melaspileella''''' is an ascomycete genus in the family '''Melaspileellaceae''', placed in the order Asterinales (class Dothideomycetes). The family was established in 2018 to accommodate the single genus ''Melaspileella'', which contains only '''''M. proximella''''', a species originally described in 1861. Long misclassified as a lichen and moved through various genera, molecular studies confirmed it is actually a non-lichenised saprophyte living on tree bark. The fungus is characterised by minute black fruiting bodies and distinctive ascospores bearing slender appendages that are visible when wet but disappear upon drying. Found across temperate and boreal regions of the Northern Hemisphere on both conifers and broad-leaved trees, it remains rarely encountered, likely due to its tiny size and inconspicuous appearance.
==Taxonomy==
Melaspileellaceae was established in 2018 by Dong-Qin Dai, Kevin D. Hyde and co-authors, who used DNA sequence data to show that ''Melaspileella'' forms a distinct clade within Asterinales, sister to Hemigraphaceae, and therefore merits recognition as a separate family.<ref name="Dai et al. 2018"/> Recent classification summaries treat Melaspileellaceae as containing a single genus, ''Melaspileella'', and regard that genus as monospecific with only ''Melaspileella proximella'' accepted.<ref name="FoF"/><ref name="Dothideomycetes.org"/>
The generic name was originally introduced by Petter Karsten as a subgenus,<ref name="Karsten 1885"/> ''Melaspileella'' (as a subdivision of ''Celidium''), to accommodate three species: ''Celidium nephromiarium'', ''C. neglectulum'' and ''C. proximellum''.<ref name="Dothideomycetes.org"/> Edvard Vainio later raised ''Melaspileella'' to generic rank in 1921, applying it to two species that had previously been included in ''Melaspilea'' in the loose sense (''M. microspilota'' and ''M. pandani'') and treating ''M. proximella'' as the type species of the genus.<ref name="Dothideomycetes.org"/> Around the same period, other authors created combinations such as ''Melaspileella nephromiaria'' for species originally described in ''Arthonia'' and related genera, which contributed to a heterogeneous and taxonomically unstable concept of ''Melaspileella''.<ref name="Dothideomycetes.org"/><ref name="SF_nephromiaria"/>
The fungus now known as ''Melaspileella proximella'' was first described by William Nylander in 1861 as ''Arthonia proximella'', reflecting an early assumption that it was a lichenised member of Arthoniaceae.<ref name="FoF"/> It was subsequently moved through several genera and families, at various times placed in ''Catillaria'', ''Melaspilea'', and ''Buellia'', or segregated in the genus ''Banhegyia'', which illustrates the long-standing uncertainty about its true relationships.<ref name="CLH"/> A molecular study by Damien Ertz and Paul Diederich, published in 2015,<ref name="Ertz & Diederich 2015"/> showed that ''Melaspilea'' (in the loose sense) and related "melaspileoid" fungi belong to several unrelated lineages within Dothideomycetes and demonstrated that ''Melaspileella proximella'' is not part of Arthoniomycetes but rather belongs in Asterinales.<ref name="Dai et al. 2018"/> In that work they lectotypified the genus with ''M. proximella'', transferred ''Banhegyia setispora'' to ''Melaspileella'' as a synonym of ''M. proximella'' on morphological grounds, and moved the genus to Asterinales without assigning it to a family.<ref name="Dai et al. 2018"/><ref name="Dothideomycetes.org"/>
Subsequent phylogenetic analyses by Dai and co-authors confirmed that sequences of ''M. proximella'' form an independent lineage in Asterinales, leading to the formal introduction of Melaspileellaceae to accommodate this single genus.<ref name="Dai et al. 2018"/> At the same time, modern treatments have not retained the other historical combinations in ''Melaspileella'': Vainio's species ''M. microspilota'' and ''M. pandani'' are treated as former ''Melaspilea'' sensu lato species that have not been included in the current, sequence-based circumscription of the genus, while ''Melaspileella nephromiaria'' is now regarded in Species Fungorum as an alternative name for ''Arthonia patellulata'' var. ''nephromiaria'' and placed in Arthoniaceae rather than in Melaspileellaceae.<ref name="Dothideomycetes.org"/><ref name="SF_nephromiaria"/> As a result, recent phylogenetic and classification works consider ''Melaspileella'' to be a monotypic genus containing only ''M. proximella''.<ref name="Dai et al. 2018"/><ref name="FoF"/><ref name="Dothideomycetes.org"/>
==Description==
''Melaspileella'' produces tiny, black fruiting bodies that appear as solitary, rounded stromatic ascomata on the surface of bark. The outer wall (peridium) of each ascoma consists of two layers: an external layer of thick-walled, black cells and an inner layer of lighter brown to nearly hyaline cells of a {{language|la|textura angularis}} type. Inside the ascomata, numerous filamentous pseudoparaphyses (sterile filaments) are present; they are hyaline and mostly unbranched, but have brownish pigmented tips around the asci. The asci are eight-spored, {{lichengloss|bitunicate}} (having a double wall), and broadly club-shaped ({{lichengloss|clavate}}) to almost spherical in shape, with a rounded apex and a short stalk (pedicel). Each ascus contains eight ascospores that are hyaline, one-septate (two-celled), with the upper cell slightly larger than the lower cell. A distinctive feature of the spores is that they bear 2–3 slender appendages ({{lichengloss|setulae}}) at the poles; these appendages are visible in fresh or wet spores but tend to disappear when the spore dries. No asexual reproductive stage is known for ''Melaspileella'' (the fungus is only known from its sexual morph).<ref name="Dai et al. 2018"/>
==Habitat and distribution==
''Melaspileella proximella'' is a saprobic fungus that grows on the bark of living or dead woody plants.<ref name="Dai et al. 2018"/> It does not form a lichen thallus (no {{lichengloss|photobiont}} is present), although it may superficially resemble a thin crust on bark (a "crustose, {{lichengloss|endophloedal}}" growth).<ref name="CLH"/> This species has been recorded on the trunks and branches of a variety of trees and shrubs, including conifers like pine (''Pinus'') and juniper (''Juniperus''), as well as broad-leaved trees such as linden (''Tilia''). The species is interpreted as a saprobe of bark tissues rather than a pathogen of the host plant.<ref name="Hongsanan et al. 2020"/> In terms of distribution, ''Melaspileella proximella'' is known from temperate regions of the Northern Hemisphere. It has been documented in multiple parts of Europe (for example, Scandinavia and central Europe) and in eastern North America.<ref name="CLH"/> Recent records also indicate its presence in Asia (e.g. Siberia, Russia), suggesting a broad boreal-temperate distribution across Eurasia and North America.<ref name="Muchnik & Konoreva 2017"/><ref name="Perlmutter et al. 2015"/> However, it is generally considered a rarely encountered fungus, likely overlooked due to its minute size and inconspicuous appearance on bark.<ref name="Dai et al. 2018"/>
==References== {{Reflist|colwidth=30em|refs=
<ref name="CLH">{{cite web |title=''Melaspileella proximella'' (Nyl.) Ertz & Diederich |website=Consortium of Lichen Herbaria |url=https://lichenportal.org/portal/taxa/index.php?taxon=197411 |access-date=16 November 2025}}</ref>
<ref name="Dai et al. 2018">{{cite journal |last1=Dai |first1=Dong-Qin |last2=Tang |first2=Li-Zhou |last3=Liu |first3=Chao |last4=Wang |first4=Hai-Bo |last5=Hyde |first5=Kevin D. |title=Studies on Parmulariaceae I. A phylogeny based on available sequence data; introducing Parmulariales ord. nov., and Hemigraphaceae, Melaspileellaceae and Stictographaceae fam. nov. |journal=Phytotaxa |volume=369 |issue=2 |year=2018 |doi=10.11646/phytotaxa.369.2.1 |pages=63–79}}</ref>
<ref name="Dothideomycetes.org">{{cite web |title=Melaspileella |website=Dothideomycetes.org |publisher=Mushroom Research Foundation |url=https://dothideomycetes.org/eremithallales/melaspileaceae/melaspileella/ |access-date=16 November 2025}}</ref>
<ref name="Ertz & Diederich 2015">{{cite journal |last1=Ertz |first1=Damien |last2=Diederich |first2=Paul |title=Dismantling Melaspileaceae: a first phylogenetic study of ''Buelliella'', ''Hemigrapha'', ''Karschia'', ''Labrocarpon'' and ''Melaspilea'' |journal=Fungal Diversity |volume=71 |issue=1 |year=2015 |doi=10.1007/s13225-015-0321-1 |pages=141–164}}</ref>
<ref name="FoF">{{cite web |last=Chethana |first=Thilini |title=Facesoffungi number: FoF 03911 |website=Faces Of Fungi |date=8 June 2022 |url=https://www.facesoffungi.org/melaspileellaceae/ |access-date=16 November 2025}}</ref>
<ref name="Hongsanan et al. 2020">{{cite journal |display-authors=6 |last1=Hongsanan |first1=Sinang |last2=Hyde |first2=Kevin D. |last3=Phookamsak |first3=Rungtiwa |last4=Wanasinghe |first4=Dhanushka N. |last5=McKenzie |first5=Eric H. C. |last6=Sarma |first6=V. Venkateswara |last7=Lücking |first7=Robert |last8=Boonmee |first8=Saranyaphat |last9=Bhat |first9=Jayarama D. |last10=Liu |first10=Ning-Guo |last11=Tennakoon |first11=Danushka S. |last12=Pem |first12=Dhandevi |last13=Karunarathna |first13=Anuruddha |last14=Jiang |first14=Shu-Hua |last15=Jones |first15=Gareth E. B. |last16=Phillips |first16=Alan J. L. |last17=Manawasinghe |first17=Ishara S. |last18=Tibpromma |first18=Saowaluck |last19=Jayasiri |first19=Subashini C. |last20=Sandamali |first20=Diana |last21=Jayawardena |first21=Ruvishika S. |last22=Wijayawardene |first22=Nalin N. |last23=Ekanayaka |first23=Anusha H. |last24=Jeewon |first24=Rajesh |last25=Lu |first25=Yong-Zhong |last26=Phukhamsakda |first26=Chayanard |last27=Dissanayake |first27=Asha J. |last28=Zeng |first28=Xiang-Yu |last29=Luo |first29=Zong-Long |last30=Tian |first30=Qing |last31=Thambugala |first31=Kasun M. |last32=Dai |first32=Dongqin |last33=Samarakoon |first33=Milan C. |last34=Chethana |first34=K. W. Thilini |last35=Ertz |first35=Damien |last36=Doilom |first36=Mingkwan |last37=Liu |first37=Jian-Kui (Jack) |last38=Pérez-Ortega |first38=Sergio |last39=Suija |first39=Ave |last40=Senwanna |first40=Chanokned |last41=Wijesinghe |first41=Subodini N. |last42=Niranjan |first42=Mekala |last43=Zhang |first43=Sheng-Nan |last44=Ariyawansa |first44=Hiran A. |last45=Jiang |first45=Hong-Bo |last46=Zhang |first46=Jin-Feng |last47=Norphanphoun |first47=Chada |last48=de Silva |first48=Nimali I. |last49=Thiyagaraja |first49=Vinodhini |last50=Zhang |first50=Huang |last51=Bezerra |first51=Jadson D. P. |last52=Miranda-González |first52=Ricardo |last53=Aptroot |first53=André |last54=Kashiwadani |first54=Hiroyuki |last55=Harishchandra |first55=Dulanjalee |last56=Sérusiaux |first56=Emmanuël |last57=Abeywickrama |first57=Pranami D. |last58=Bao |first58=Dan-Feng |last59=Devadatha |first59=Bandarupalli |last60=Wu |first60=Hai-Xia |last61=Moon |first61=Kwang Hee |last62=Gueidan |first62=Cecile |last63=Schumm |first63=Felix |last64=Bundhun |first64=Digvijayini |last65=Mapook |first65=Ausana |last66=Monkai |first66=Jutamart |last67=Bhunjun |first67=Chitrabhanu S. |last68=Chomnunti |first68=Putarak |last69=Suetrong |first69=Satinee |last70=Chaiwan |first70=Napalai |last71=Dayarathne |first71=Monika C. |last72=Yang |first72=Jing |last73=Rathnayaka |first73=Achala R. |last74=Xu |first74=Jian-Chu |last75=Zheng |first75=Jiesheng |last76=Liu |first76=Gang |last77=Feng |first77=Yao |last78=Xie |first78=Ning |title=Refined families of Dothideomycetes: orders and families incertae sedis in Dothideomycetes |journal=Fungal Diversity |volume=105 |issue=1 |year=2020 |doi=10.1007/s13225-020-00462-6 |doi-access=free |pages=17–318}}</ref>
<ref name="Karsten 1885">{{cite journal |last=Karsten |first=P.A. |year=1885 |title=Revisio monographica atque synopsis Ascomycetum in Fennia hucusqve detectorum |trans-title=A Monographic Revision and Synopsis of Ascomycetes Found in Finland to Date |journal=Acta Societatis pro Fauna et Flora Fennica |volume=2 |issue=6 |page=163 |language=la}}</ref>
<ref name="MycoBank">{{cite web |title=''Melaspileella proximella'' |website=MycoBank |publisher=Westerdijk Fungal Biodiversity Institute |url=https://www.mycobank.org/page/Name%20details%20page/field/Mycobank%20%23/811374 |access-date=16 November 2025}}</ref>
<ref name="Muchnik & Konoreva 2017">{{cite journal |last1=Muchnik |first1=Eugenia E. |last2=Konoreva |first2=Liudmila A. |title=New and noteworthy records of lichens and allied fungi from Central European Russia |journal=Herzogia |volume=30 |issue=2 |year=2017 |doi=10.13158/heia.30.2.2017.509 |pages=509–514 |url=https://www.researchgate.net/publication/321749867}}</ref>
<ref name="Olariaga">{{cite web |last=Olariaga |first=I. |title=''Melaspileella proximella'' |website=Micología Ibérica |url=https://micologiaiberica.org/en/services/melaspileella-proximella/ |access-date=16 November 2025}}</ref>
<ref name="Perlmutter et al. 2015">{{cite journal |last1=Perlmutter |first1=Gary B. |last2=Tucker |first2=Shirley C. |last3=Rivas Plata |first3=Eimy |last4=Clerc |first4=Philippe |last5=Lücking |first5=Robert |title=''Melaspilea demissa'' (Tuck.) Zahlbr. (lichenized Ascomycota) in eastern North America with a key to North American species of ''Melaspilea'' s. lat. |journal=The Lichenologist |volume=47 |issue=3 |year=2015 |doi=10.1017/S0024282915000080 |pages=167–182}}</ref>
<ref name="Species Fungorum synonymy">{{cite web |title=GSD Species Synonymy. Current Name: ''Melaspileella proximella'' (Th. Fr.) Boud., Hist. Class. Discom. Eur. (Paris): 182 (1907) |url=https://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=636682 |publisher=Species Fungorum |access-date=16 November 2025}}</ref>
<ref name="SF_nephromiaria">{{cite web |title=''Melaspileella nephromiaria'' |website=Index Fungorum |publisher=Royal Botanic Gardens, Kew |url=https://www.indexfungorum.org/names/namesrecord.asp?RecordID=239825 |access-date=16 November 2025}}</ref>
}}
{{Taxonbar |from1=Q23073007 |from2=Q23057453 |from3=Q106626195 |from4=Q59539232 |from5=Q106626326 |from6=Q106640934 |from7=Q106640372 |from8=Q10580994 |from9=Q106647510}}
Category:Dothideomycetes Category:Dothideomycetes genera Category:Taxa described in 1921 Category:Taxa named by Petter Adolf Karsten