{{Short description|Genus of lichen-forming fungi}} {{Use British English|date=September 2023}} {{Use dmy dates|date=May 2023}} {{Automatic taxobox | image = Caloplaca arizonica - Flickr - pellaea.jpg | image_caption = ''Opeltia arizonica'' growing on juniper wood near Canyonlands National Park, Utah | taxon = Opeltia | authority = S.Y.Kondr. & Lőkös (2017) | type_species = Opeltia neobaltistanica | type_species_authority = (S.Y.Kondr., Lőkös & Hur) S.Y.Kondr. & Lőkös (2017) | subdivision_ranks = Species | subdivision = ''O. arizonica''<br /> ''O. flavorubescens''<br /> ''O. juniperina''<br /> ''O. neobaltistanica'' }}

'''''Opeltia''''' is a genus of lichen-forming fungi in the family Teloschistaceae. It has four species of corticolous (bark-dwelling), crustose lichens.<ref name="CoL"/>

==Taxonomy== The genus was circumscribed in 2017 by lichenologists Sergey Kondratyuk and Laszlo Lőkös, with ''O.&nbsp;neobaltistanica'' assigned as the type species. The genus name honours lichenologist Josef Poelt, "in recognition of his enormous contribution to lichenology".<ref name="Kondratyuk et al. 2017"/>

''Opeltia'' occupies a distinct monophyletic branch within the ''Mikhtomia'' clade, a phylogenetically related group of taxa that also includes the genera ''Hanstrassia'', ''Laundonia'', and ''Oxneriopsis''. This clade is in the subfamily Caloplacoideae of the family Teloschistaceae.<ref name="Kondratyuk et al. 2017"/>

==Description==

''Opeltia'' shares similarities with ''Blastenia''. However, it can be distinguished by certain key characteristics. The thallus of ''Opeltia'' has a crustose form, appearing {{lichengloss|areolate}} to {{lichengloss|squamulose|subsquamulose}} with an abrupt margin. Its colouration varies, typically presenting in shades of whitish, dirty white, and occasional yellowish tones. ''Opeltia'' lacks asexual propagules or soredia.<ref name="Kondratyuk et al. 2017"/>

The apothecia of ''Opeltia'' are {{lichengloss|biatorine}}, occasionally manifesting as {{lichengloss|zeorine}}, biatorine, or {{lichengloss|lecanorine}}. The distinctive feature is the dark reddish-orange to rusty brown colouration of the apothecial {{lichengloss|disc}}. The {{lichengloss|true exciple}} in ''Opeltia'' has a {{lichengloss|paraplectenchymatous}} structure in the basal portion, transitioning into a mesodermatous paraplectenchymatous form with a well-developed matrix. A noteworthy trait is the presence of oil in the hymenium and subhymenium. Reproduction in ''Opeltia'' is characterized by eight-spored asci and {{lichengloss|polarilocular}} ascospores that can be quite variable in shape.<ref name="Kondratyuk et al. 2017"/>

==Habitat and distribution==

''Opeltia neobaltistanica'', and ''O.&nbsp;juniperina'' occur in Eurasia, while ''O.&nbsp;arizonica'' occurs in southern North America.<ref name="Kondratyuk et al. 2017"/>

==Species==

* ''Opeltia arizonica'' {{au|(H.Magn.) S.Y.Kondr. & Lőkös (2017)}} * ''Opeltia flavorubescens'' {{au|(Huds.) S.Y.Kondr. & Hur (2020)}}<ref name="Mishra et al. 2020"/> * ''Opeltia juniperina'' {{au|(Tomin) S.Y.Kondr. & Lőkös (2017)}} * ''Opeltia neobaltistanica'' {{au|(S.Y.Kondr., Lőkös & Hur) S.Y.Kondr. & Lőkös (2017)}}

==References== {{Reflist|refs=

<ref name="CoL">{{Catalogue of Life |id=68N9 |title=''Opeltia'' |access-date=20 September 2023}}</ref>

<ref name="Kondratyuk et al. 2017">{{cite journal |last1=Kondratyuk |first1=S.Y. |last2=Lőkös |first2=L. |last3=Upreti |first3=D.K. |last4=Nayaka |first4=S. |last5=Mishra |first5=G.K. |last6=Ravera |first6=S. |last7=Jeong |first7=M.-H. |last8=Jang |first8=S.-H. |last9=Park |first9=J.S. |last10=Hur |first10=J.S. |year=2017 |title=New monophyletic branches of the Teloschistaceae (lichen-forming Ascomycota) proved by three gene phylogeny |journal=Acta Botanica Hungarica |volume=59 |issue=1–2 |pages=71–136 [112–113] |doi=10.1556/034.59.2017.1-2.6 |hdl=10447/414429|hdl-access=free }}</ref>

<ref name="Mishra et al. 2020">{{cite journal |last1=Mishra |first1=G.K. |last2=Upreti |first2=D.K. |last3=Nayaka |first3=S. |last4=Thell |first4=A. |last5=Kärnefelt |first5=I. |last6=Lőkös |first6=L. |last7=Hur |first7=J.-S. |last8=Sinha |first8=G.P. |last9=Kondratyuk |first9=S.Y. |title=Current taxonomy of the lichen family Teloschistaceae from India with descriptions of new species |journal=Acta Botanica Hungaricae |volume=62 |issue=3–4 |year=2020 |doi=10.1556/034.62.2020.3-4.5 |pages=309–391 |s2cid=228982203|doi-access=free }}</ref>

}}

{{Taxonbar|from=Q43616736}}

Category:Teloschistales Category:Teloschistales genera Category:Lichen genera Category:Taxa described in 2017 Category:Taxa named by Sergey Kondratyuk