Parmelia saxatilis, commonly known as the salted shield lichen or crottle,[4] is a species of foliose lichen in the family Parmeliaceae. Several morphologically similar species, formerly lumped together, are now distinguished by their DNA.
The lichen has a greenish-gray to bluish-gray thallus that can turn brown in exposed locations. It typically grows on rock, although it is sometimes found on bark or wood. Parmelia saxatilis is used to make dyes with deep red-brown and rusty-orange colors.[4] Known as "crotal" in Scotland, it was used to dye traditional cloths including Harris tweed.[9][10] A somewhat similar species complex with a cosmopolitan distribution is the Parmelia sulcata group, generally growing on trees.
Conservation
In 2021, Parmelia saxatilis was assessed for the global IUCN Red List. Because the lichen is common, abundant, and widely distributed with a stable population size, it is considered of least concern.[1]
References
^ abYahr, R.; Allen, J.; Lymbery, C.; Batallas-Molina, R.; Bungartz, F.; Dal Forno, M.; Howe, N.; Lendemer, J.; McMullin, T.; Mertens, A.; Paquette, H.; Petix, M.; Reese Næsborg, R.; Roberts, F.; Sharrett, S.; Villella, J. (18 May 2021). "Parmelia saxatilis". The IUCN Red List of Threatened Species 2021. Retrieved 5 September 2021.
^Acharius E. (1803). Methodus qua Omnes Detectos Lichenes Secundum Organa Carpomorpha ad Genera, Species et Varietates Redigere atque Observationibus Illustrare Tentavit Erik Acharius (in Latin). Stockholm: Ulrich. p. 204.
^ abBrodo IM, Sharnoff SD, Sharnoff S (2001). Lichens of North America. New Haven and London: Yale University Press. p. 483. ISBN978-0-300-08249-4.
^Linnaeus, Carl (1753). Species Plantarum (in Latin). Vol. 2. Stockholm: Impensis Laurentii Salvii. p. 1142.
^Crespo, Ana; J. Rico, Víctor; Garrido, Elisa; Lumbsch, H. Thorsten; Divakar, Pradeep K. (2020). "A revision of species of the Parmelia saxatilis complex in the Iberian Peninsula with the description of P. rojoi, a new potentially relict species". The Lichenologist. 52 (5): 365–376. doi:10.1017/S0024282920000341. S2CID229038392.
^Corsie, Eleanor I.; Harrold, Paul; Yahr, Rebecca (2019). "No combination of morphological, ecological or chemical characters can reliably diagnose species in the Parmelia saxatilis aggregate in Scotland". The Lichenologist. 51 (2): 107–121. doi:10.1017/S0024282919000069. S2CID150128064.
^Beatrice Castellani, Maria; Bianchi, Elisabetta; Coppi, Andrea; Nascimbene, Juri; Benesperi, Renato (20 July 2021). "Revision of the Parmelia saxatilis group in Italy based on morphological, chemical, and molecular data". Phytotaxa. 512 (1). doi:10.11646/PHYTOTAXA.512.1.2. S2CID237667756.{{cite journal}}: CS1 maint: date and year (link)
^Fraser, Jean: Traditional Scottish Dyes, Canongate, 1983