{{Short description|Species of lichen-forming fungus}} {{Use dmy dates|date=October 2025}} {{Use Oxford spelling|date=October 2025}} {{Speciesbox | image = | image_caption = | taxon = Pyxine philippina | authority = [[Vain.]] (1913) }}
'''''Pyxine philippina''''' is a species of [[foliose lichen]] in the family [[Caliciaceae]].<ref name="CoL_SCSVP"/> It was first discovered in the Philippines, growing on tree bark in the mountainous regions of [[Luzon]]. The lichen forms a thin to moderately thick, leaf-like body with a whitish upper surface and blackish underside, anchored by short root-like structures called [[rhizine]]s. Since its original description, it has been widely documented across Asia, including in Bhutan, India, Japan, Nepal, and Thailand.
==Taxonomy==
''Pyxine philippina'' was first [[species description|described scientifically]] by the Finnish lichenologist [[Edvard August Vainio]] in 1913. The [[botanical name|species epithet]] ''philippina'' refers to its [[type locality (biology)|type locality]] in the Philippine Islands. Vainio noted that this species is closely related to ''[[Pyxine denudatula]]'', from which it can be distinguished by differences in the colour of the {{lichengloss|epithecium}} (uppermost layer of the spore-producing tissue). The species also shows some similarities to ''[[Pyxine retirugella]]'', but differs in having a {{lichengloss|rugulose}} (wrinkled) rather than {{lichengloss|laciniate}} (deeply divided) [[thallus]] with a granular margin.<ref name="Vainio 1913"/>
==Description==
''Pyxine philippina'' is a [[foliose lichen]], meaning it has a leaf-like [[lichen growth forms|growth form]]. The thallus (the vegetative body of the lichen) is thin to moderately thick and lacks both [[soredia]] (powdery [[propagule]]s) and [[isidia]] (coral-like outgrowths). The upper surface is whitish, fairly opaque, and {{lichengloss|epruinosus}} (without a pruinose or frosted covering), appearing smooth. The [[medulla (lichenology)|medulla]] (inner layer) is white. When tested with [[potassium hydroxide]] solution (the [[K test]]), the upper surface turns lutescent (yellowish), followed by rubescent (reddish). The {{lichengloss|lobes}} (divisions of the thallus) measure 0.5–1.4 mm in width and are irregular in shape, somewhat contiguous (nearly touching), and confluent (flowing together), often very confluent. They are flat or partially convex, appearing blackish beneath. The [[rhizine]]s (root-like attachment structures) are short and blackish in colour.<ref name="Vainio 1913"/>
The [[apothecia]] (disc-shaped [[fruiting bodies]] that produce spores) measure 1–4 mm in width and are {{lichengloss|lecideine}} in form (lacking a distinct {{lichengloss|thalline margin}} formed by thallus tissue). The margin is blackish or occasionally ashy-blackish in colour, fairly slender or of moderate thickness, whilst the {{lichengloss|disc}} is flat, black, and nude (bare in texture). The {{lichengloss|excipulum}} (outer rim of the apothecium) has an interior that is [[verdigris]] to sooty coloured and reacts strongly to potassium hydroxide, or occasionally appears whitish to ashy.<ref name="Vainio 1913"/>
The {{lichengloss|hypothecium}} is distinctly brownish above and shows no reaction to potassium hydroxide, whilst appearing whitish below or occasionally becoming ashy. The spores, which number eight per [[ascus]], are arranged in two rows, appearing brownish, oblong, and blunt to {{lichengloss|polarilocular}} (with polar thickenings separated by a thick septum containing a connecting channel). The spores are divided by a single [[septum|cross-wall]] (1-septate) with membranes that are unequally thickened, particularly in the apices and at the septum, measuring 15–23 [[micrometre]]s (μm) in length and 6–8 μm in width.<ref name="Vainio 1913"/>
==Habitat and distribution==
''Pyxine philippina'' was originally described from specimens collected at two locations in the Philippines. The type material includes collections from [[Luzon]] (Subprovince [[Bontoc, Mountain Province|Bontoc]], Vanoverbergh 780) and from Subprovince [[Benguet]] (Merrill 7934), both growing on tree bark.<ref name="Vainio 1913"/> ''Pyxine philippina'' is one of 14 ''[[Pyxine]]'' species that have been recorded from the Philippines,<ref name="Paguirigan 2020"/> and one of nine in the genus that was first described from specimens collected in the country.<ref name="dela Cruz et al. 2024"/> The lichen has since been widely documented across Asia, including Bhutan,<ref name="Aptroot & Feijen 2002"/> India,<ref name="Singh et al. 2018"/> Japan,<ref name="Harada 2004"/> Nepal,<ref name="Baniya & Bhatta 2021"/> and Thailand.<ref name="Buaruang et al. 2017"/>
==References== {{Reflist|colwidth=30em|refs=
<ref name="Aptroot & Feijen 2002">{{cite journal |last1=Aptroot |first1=A. |last2=Feijen |first2=F.J. |year=2002 |title=Annotated checklist of the lichens and lichenicolous fungi of Bhutan |journal=Fungal Diversity |volume=11 |pages=21–48 |url=https://www.researchgate.net/publication/280979595}}</ref>
<ref name="Baniya & Bhatta 2021">{{cite journal |last1=Baniya |first1=Chitra Bahadur |last2=Bhatta |first2=Pooja |year=2021 |title=Exploration of Lichen in Nepal |journal=Journal of Plant Resources |volume=19 |issue=1 |pages=19–54 [50] |url=https://dpr.gov.np/wp-content/uploads/2021/08/5.-Exploration-of-Lichen-.pdf}}</ref>
<ref name="Buaruang et al. 2017">{{cite journal |last1=Buaruang |first1=Kawinnat |last2=Boonpragob |first2=Kansri |last3=Mongkolsuk |first3=Pachara |last4=Sangvichien |first4=Ek |last5=Vongshewarat |first5=Kajohnsak |last6=Polyiam |first6=Wetchasart |last7=Rangsiruji |first7=Achariya |last8=Saipunkaew |first8=Wanaruk |last9=Naksuwankul |first9=Khwanruan |last10=Kalb |first10=Jutarat |last11=Parnmen |first11=Sittiporn |last12=Kraichak |first12=Ekaphan |last13=Phraphuchamnong |first13=Phimpisa |last14=Meesim |first14=Sanya |last15=Luangsuphabool |first15=Theerapat |last16=Nirongbut |first16=Phimpha |last17=Poengsungnoen |first17=Vasun |last18=Duangphui |first18=Natwida |last19=Sodamuk |first19=Mattika |last20=Phokaeo |first20=Supatra |last21=Molsil |first21=Muthita |last22=Aptroot |first22=André |last23=Kalb |first23=Klaus |last24=Luecking |first24=Robert |last25=Lumbsch |first25=Thorsten |title=A new checklist of lichenized fungi occurring in Thailand |journal=MycoKeys |issue=23 |year=2017 |doi=10.3897/mycokeys.23.12666 |pages=1–91 [72] |doi-access=free}}</ref>
<ref name="CoL_SCSVP">{{Catalogue of Life |id=SCSVP |title=''Pyxine philippina'' Vainio |access-date=30 October 2025}}</ref>
<ref name="dela Cruz et al. 2024">{{cite journal |last1=dela Cruz |first1=Thomas Edison |last2=Llames |first2=Lloyd Christian |last3=Glori |first3=Patricia Jhoanna |last4=Sanvictores |first4=Raphael |last5=Cabales |first5=Jaius Emmanuel |last6=Aldover |first6=Glen Carlo |last7=Rejano |first7=Jomar Hebrews |last8=Akmad |first8=Bainadzma |last9=Lopez |first9=Sam |last10=Esmundo |first10=Harvy Jay |last11=Arbes |first11=Ralph Kenneth |last12=Morato |first12=Maria Katrina |last13=Agustin |first13=Angeli |last14=Nohay |first14=Jennifer Anne |last15=Cortes |first15=Brennan |last16=Bellen |first16=John Joshua |last17=Lagman |first17=Jerry |last18=Sabado |first18=Jamille |last19=Martin |first19=Kathleen Olivia |last20=Bennett |first20=Reuel |title=Checklist of novel microbes discovered in the Philippines |journal=Philippine Journal of Science |volume=153 |issue=1 |year=2024 |doi=10.56899/153.01.24 |pages=257–297 [280] |url=https://www.researchgate.net/publication/378846585}}</ref>
<ref name="Harada 2004">{{cite journal |last1=Harada |first1=H. |last2=Okamoto |first2=T. |last3=Yoshimura |first3=Y. |year=2004 |title=日本産の地衣類および関連菌類のチェックリスト |trans-title=Checklist of lichens and allied fungi of Japan |journal=Lichenology |volume=2 |pages=49–165}}</ref>
<ref name="Paguirigan 2020">{{cite journal |last=Paguirigan |first=J.A.G. |title=A checklist of lichens known from the Philippines |journal=Current Research in Environmental & Applied Mycology |volume=10 |issue=1 |year=2020 |doi=10.5943/cream/10/1/29 |doi-access=free |pages=319–376 [362–363]}}</ref>
<ref name="Singh et al. 2018">{{cite journal |last1=Singh |first1=K.P. |last2=Singh |first2=Pushpi |last3=Sinha |first3=G.P. |title=Lichen diversity in the Eastern Himalaya biodiversity hotspot region, India |journal=Cryptogam Biodiversity and Assessment |issue=1 |year=2018 |page=71–114 [97] |url=https://www.researchgate.net/publication/322740727}}</ref>
<ref name="Vainio 1913">{{cite journal |last=Vainio |first=Edvard August |title=Lichenes insularum Philippinarum. II |journal=The Philippine Journal of Science |year=1913 |volume=8 |issue=2 |pages=99–137 [110] |url=https://www.biodiversitylibrary.org/page/51382087 |language=la}}</ref>
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{{Taxonbar|from=Q10647723}}
[[Category:Caliciales]] [[Category:Lichen species]] [[Category:Lichens described in 1913]] [[Category:Lichens of the Indian subcontinent]] [[Category:Lichens of Japan]] [[Category:Lichens of Malesia]] [[Category:Lichens of Thailand]] [[Category:Taxa named by Edvard August Vainio]]