{{Short description|Species of lichen-forming fungus}} {{Use dmy dates|date=February 2026}} {{Use Oxford spelling|date=February 2026}} {{Speciesbox | image = | image_caption = | taxon = Xylographa erratica | authority = T.Sprib. (2014) }}

'''''Xylographa erratica''''' is a species of lichen-forming fungus in the family Xylographaceae.<ref name="CoL_5CLD8"/> It is a wood-inhabiting lichen that grows on conifer logs in boreal forests and on coastal driftwood, known from scattered localities across northern Europe, northeastern Asia, and western North America. The species was described in 2014 and is named for its irregularly oriented fruiting bodies, which point in different directions rather than following the wood grain.

==Taxonomy== ''Xylographa erratica'' was described as a new species by Toby Spribille in 2014. The original material (holotype) was collected in Russia's Khabarovsk Krai ({{ill|Bureinskiy Zapovednik|nl|Zapovednik Boereinski}}) from conifer logs in a ''Larix gmelinii'' forest near a stream at about 880&nbsp;m elevation. The epithet ''erratica'' refers to the species' fruiting bodies, whose tips point in irregular directions rather than aligning with the wood grain.<ref name="Spribille et al. 2014"/> The type specimen is kept in the collections of the mycological herbaria of the botanical museum of the Finnish Museum of Natural History.<ref name="Piirainen et al. 2018"/>

==Description== The species is a wood-inhabiting lichen whose sterile fungal threads (hyphae) grow through the wood and become lichenized by forming internal plugs of algal cells. As these plugs merge and expand, they can swell when wet and push apart the wood fibres, producing a cracked, "unkempt" surface appearance. The algal partner ({{lichengloss|photobiont}}) is a green, rounded ({{lichengloss|chlorococcoid}}) alga about 9–20 μm in diameter. The fruiting bodies (ascomata) are small, narrowly to broadly oval (ellipsoid), and typically develop singly, elongating in one direction. The {{lichengloss|disc}} may be exposed or partly hidden and can appear flat to concave and brown, with a pale to dark brown margin that is not strongly differentiated from the surrounding tissue. Under the microscope, the asci are 55–75&nbsp;μm long and mostly 12–15&nbsp;μm wide, each containing eight oval ascospores that are typically 11–12&nbsp;μm long and 5–6&nbsp;μm wide, though occasional spores fall outside this range. Adjacent asexual fruiting structures (conidiomata) produce long, curved, thread-like ({{lichengloss|filiform}}) conidia (asexual spores) about 15–20 × about 0.5&nbsp;μm. The thallus chemistry is characterized by stictic acid as the major lichen substance, with norstictic acid reported as trace or absent.<ref name="Spribille et al. 2014"/>

==Habitat and distribution== ''Xylographa erratica'' grows on conifer wood, including both coastal driftwood in the intertidal zone and inland wood in forest habitats. It has been reported from humid boreal conifer forests and along coastal beaches up to about 880&nbsp;m elevation, and is known from scattered localities in northern Europe, northeastern Asia, and western North America between roughly 51° and 60°N latitude. In the continental boreal forests of the Russian Far East it may be locally abundant, and it can occur in the same maritime driftwood habitats as the similar species ''X.&nbsp;opegraphella''.<ref name="Spribille et al. 2014"/>

==References== <references>

<ref name="CoL_5CLD8">{{Catalogue of Life |id=5CLD8 |title=''Xylographa erratica'' T. Sprib. |access-date=1 March 2026}}</ref>

<ref name="Piirainen et al. 2018">{{cite journal |first1=Mikko |last1=Piirainen |first2=Pertti |last2=Salo |first3=Saara |last3=Velmala |year=2018 |title=Accessions to the Botanical Museum of the Finnish Museum of Natural History, University of Helsinki, in 2017 |journal=Memoranda Societas Pro Fauna et Flora Fennica |volume=94 |pages=109–112 |url=https://helda.helsinki.fi/bitstream/handle/10138/293605/77427_Article_109988_1_10_20181228.pdf?sequence=1}}</ref>

<ref name="Spribille et al. 2014">{{cite journal |last1=Spribille |first1=Toby |last2=Resl |first2=Philipp |last3=Ahti |first3=Teuvo |last4=Pérez-Ortega |first4=Sergio |last5=Tønsberg |first5=Tor |last6=Mayrhofer |first6=Helmut |last7=Lumbsch |first7=H. Thorsten |title=Molecular systematics of the wood-inhabiting, lichen-forming genus ''Xylographa'' (Baeomycetales, Ostropomycetidae) with eight new species |journal=Acta Universitet Uppsala Symbolae Botanicae Upsalienses |year=2014 |volume=37 |issue=1 |pages=1–87 |pmid=26953522 |pmc=4747110}}</ref>

</references>

{{Taxonbar|from=Q23057469}}

Category:Baeomycetales Category:Lichen species Category:Lichens described in 2014 Category:Lichens of Northern Europe Category:Lichens of the Russian Far East Category:Lichens of North America Category:Taxa named by Toby Spribille