{{Short description|Species of lichen}} {{Use mdy dates|date=February 2021}} {{Use American English|date=February 2021}} {{Species box | image = Punctelia caseana - Flickr - pellaea.jpg | image_caption = in the Delmarva Peninsula, USA | taxon = Punctelia caseana | authority = Lendemer & B.P.Hodk. (2010) | status = LC | status_system = IUCN3.1 | status_ref = <ref name="IUCN: Punctelia caseana"/> | status2 = G5 | status2_system = TNC | status2_ref = <ref name=NS>{{cite NatureServe |id=2.857817 |title=''Punctelia caseana'' |access-date=3 November 2025}}</ref> }}

'''''Punctelia caseana''''' is a species of foliose lichen in the family Parmeliaceae. Its range covers eastern North America, extending south to central and northern Mexico, where it grows on the bark of many species of hardwood and conifer trees.

==Taxonomy== ''Punctelia caseana'' was described as a new species in 2010 by lichenologists James Lendemer and Brendan Hodkinson. The type was collected in the Nature Conservancy reserve in Atlantic County, New Jersey. The specific epithet ''caseana'' honors Martha A. Case, who was an undergraduate professor of Hodkinson and encouraged his interest in lichenology.<ref name="Lendemer & Hodkinson 2010"/>

==Description== The color of the upper surface of the thallus of ''Punctelia caseana'' is grey-blue, while the undersurface is pale to off-white, sometimes light brown. The size of the thallus is quite variable, depending largely on the microhabitat conditions. There are many soralia, which are mostly located along the margins of the lobes. The soredia are coarse and large. Ascospores produced by the lichen are hyaline, measuring 14–17 by 10–12&nbsp;μm.<ref name="Lendemer & Hodkinson 2010"/> It contains the secondary compounds atranorin, chloroatroanorin, and lecanoric acid. The standard lichen spot test results are K+ (yellow), C−, KC−, P−, and UV− in the upper cortex; in the medulla they are K−, KC+ (red), C+ (red), P−, and UV−.<ref name="Egan & Lendemer 2016"/>

''Punctelia caseana'' can be readily distinguished from the common North American species ''Punctelia rudecta'' because the latter has isidia rather than soredia.<ref name="Tripp & Lendemer 2020"/> Two lookalikes, ''Punctelia perrituculata'' and ''P.&nbsp;subrudecta'', both produce medullary gyrophoric acid and have a pale lower surface, like ''Punctelia caseana''. However, they have short conidia, and ''P.&nbsp;perrituculata'' has a surface texture covered with small round pits or grooves (''scrobiculae'').<ref name="Egan & Lendemer 2016"/>

==Habitat and distribution== It is found in the eastern United States on many types of hardwood trees, as well as conifers, and occasionally on rotting logs.<ref name="Tripp & Lendemer 2020"/> Its distribution in the eastern US is similar to that of ''Punctelia subrudecta''.<ref name="Lendemer & Hodkinson 2010"/> The range of ''Punctelia caseana'' was later extended to include eastern and central Mexico.<ref name="Egan & Lendemer 2016"/>

==Conservation== In 2021, ''Punctelia caseana'' was assessed for the global IUCN Red List. Because it has an abundant and widespread population in North America with no sign of decline, it is considered a species of least concern.<ref name="IUCN: Punctelia caseana"/>

==References== {{Reflist|refs=

<ref name="Egan & Lendemer 2016">{{cite book |last1=Egan |first1=R.S. |last2=Lendemer |first2=J. |chapter=''Punctelia'' in Mexico |year=2016 |editor-last1=Herrera-Campos |editor-first1=Maria |editor-last2=Pérez-Pérez |editor-first2=Rosa Emilia |editor-link3=Thomas Hawkes Nash III |editor-last3=Nash III |editor-first3=Thomas H. |title=Lichens of Mexico. The Parmeliaceae – Keys, distribution and specimen descriptions |pages=453–480 |publisher=J. Cramer |location=Stuttgart |isbn=978-3-443-58089-6}}</ref>

<ref name="IUCN: Punctelia caseana">{{cite iucn |last1=Scott |first1=T. |year=2021 |title=''Punctelia caseana'' |volume=2021 |article-number=e.T194662148A194678174 |doi=10.2305/IUCN.UK.2021-2.RLTS.T194662148A194678174.en |access-date=5 September 2021}}</ref>

<ref name="Lendemer & Hodkinson 2010">{{cite journal |last1=Lendemer |first1=James C. |last2=Hodkinson |first2=Brendan P. |title=A new perspective on ''Punctelia subrudecta'' (Parmeliaceae) in North America: previously rejected morphological characters corroborate molecular phylogenetic evidence and provide insight into an old problem |journal=Lichenologist |volume=42 |issue=4 |year=2011 |pages=405–421 |doi=10.1017/S0024282910000101}}</ref>

<ref name="Tripp & Lendemer 2020">{{cite book |last1=Tripp |first1=Erin A. |last2=Lendemer |first2=James C. |year=2020 |title=Field Guide to the Lichens of Great Smoky Mountains National Park |page=389 |publisher=The University of Tennessee Press |location=Knoxville |isbn=978-1-62190-514-1}}</ref>

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caseana Category:Lichen species Category:Lichens described in 2010 Category:Lichens of Mexico Category:Lichens of the United States Category:Taxa named by Brendan Paul Hodkinson Category:Taxa named by James Lendemer