{{Short description|Species of lichen in the family Parmeliaceae}} {{Speciesbox | image = Hypogymnia physodes.jpeg | status = G5 | status_system = TNC | status_ref = <ref name=NS>{{cite NatureServe |id=2.121872 |title=''Hypogymnia physodes'' |access-date=17 September 2025}}</ref> | taxon = Hypogymnia physodes | authority = ([[Carl Linnaeus|L.]]) [[Nyl.]] (1896) | synonyms = *''Lichen physodes'' {{sm|L. (1753)}} }}
'''''Hypogymnia physodes''''', commonly known as the '''monk's-hood lichen''', is a species of [[foliose lichen]] in the family [[Parmeliaceae]]. It is a common and widespread species in [[boreal forest|boreal]] and [[temperate]] forests of the [[Northern Hemisphere]]. It has a grey to yellowish-green [[thallus]] that is loosely attached to its [[substrate (biology)|substrate]] and forms large irregular patches. Hollow lobes are 2–3mm wide. The outer edge turns up and is frequently covered with white powdery [[soredia]] underneath. Its lower surface is black, wrinkled and has some browning toward the lobe margins. The [[pycnidia]] are black and abundant, and their presence creates a pepper-like effect across the upper surface.<ref name="Brodo et al. 2001"/> Because of its abundance and its moderate sensitivity to [[sulphur dioxide]] and [[heavy metals]], ''Hypogymnia physodes'' is often used in [[bioindicator]] and [[biomonitoring]] studies that enable the assessment of [[air pollution]] and other environmental conditions.<ref name="Hauck et al. 2013"/><ref name="Herzig et al. 1989"/>
==Extract== ''Hypogymnia physodes'' extract is recognised as having pharmacological potential. Its major component is [[physodic acid]], which is able to cross the [[blood-brain barrier]].<ref name="Cancers2021">{{cite journal |last1=Studzińska-Sroka |first1=E |last2=Majchrzak-Celińska |first2=A |last3=Zalewski |first3=P |last4=Szwajgier |first4=D |last5=Baranowska-Wójcik |first5=E |last6=Żarowski |first6=M |last7=Plech |first7=T |last8=Cielecka-Piontek |first8=J |title=Permeability of ''Hypogymnia physodes'' Extract Component-Physodic Acid through the Blood-Brain Barrier as an Important Argument for Its Anticancer and Neuroprotective Activity within the Central Nervous System. |journal=Cancers |date=5 April 2021 |volume=13 |issue=7 |page=1717 |doi=10.3390/cancers13071717 |doi-access=free |pmid=33916370 |pmc=8038629 }}</ref>
==See also== * [[List of lichens named by Carl Linnaeus]]
==References== {{Reflist|colwidth=30em|refs=
<ref name="Brodo et al. 2001">{{cite book |first1=Irwin M. |last1=Brodo |first2=Sylvia Duran |last2=Sharnoff |first3=Stephen |last3=Sharnoff |title=Lichens of North America |year=2001 |publisher=Yale University Press |page=354 |isbn=978-0300082494}}</ref>
<ref name="Hauck et al. 2013">{{cite journal |last1=Hauck |first1=Markus |last2=Böning |first2=Janina |last3=Jacob |first3=Mascha |last4=Dittrich |first4=Sebastian |last5=Feussner |first5=Ivo |last6=Leuschner |first6=Christoph |title=Lichen substance concentrations in the lichen ''Hypogymnia physodes'' are correlated with heavy metal concentrations in the substratum|journal=Environmental and Experimental Botany |volume=85 |year=2013 |pages=58–63 |doi=10.1016/j.envexpbot.2012.08.011 |bibcode=2013EnvEB..85...58H }}</ref>
<ref name="Herzig et al. 1989">{{cite journal |last1=Herzig |first1=R. |last2=Liebendörfer |first2=L. |last3=Urech |first3=M. |last4=Ammann |first4=K. |last5=Cuecheva |first5=M. |last6=Landolt |first6=W. |title=Passive Biomonitoring with Lichens as a Part of an Integrated Biological Measuring System for Monitoring Air Pollution in Switzerland |journal=International Journal of Environmental Analytical Chemistry |volume=35 |issue=1 |year=1989 |pages=43–57 |doi=10.1080/03067318908028377 |bibcode=1989IJEAC..35...43H }}</ref>
}}
{{Taxonbar|from=Q881824}}
[[Category:Hypogymnia|physodes]] [[Category:Lichen species]] [[Category:Lichens described in 1753]] [[Category:Lichens of North America]] [[Category:Lichens of Asia]] [[Category:Lichens of Europe]] [[Category:Fungal taxa named by Carl Linnaeus]]