Taxonomic Notes: Hue (1899) described Parmelia pachyderma from Montevideo, Uruguay. Hale (1976) combined it in the genus Everniastrum, and Culberson and Culberson (1981) described it in the new endemic genus Concamerella. In 2005, based on genetic evidence from Concamerellafistulata (Tayl.) W Culb. & C. Culb., the Parmotrema pachydermum species was finally placed in the genus Parmotrema (Blanco et al. 2005).
This species is endemic to Rio Grande do Sul State (southern Brazil) and Uruguay, and is suffering habitat loss for extensive soy plantations, associated with fires. Recent reports of it are rare and the biggest subpopulation known from field observations (at Piratini Municipality, Rio Grande do Sul State) during the years 2011-2019 is becoming heavily threatened from the surrounding soy plantations and use of fire, being restricted to only some rocks that are not at the border with the soy plantations. Due to the small population size (up to 157 mature individuals) with up to 50 mature individuals in the biggest subpopulation (considering the lower end of the population size estimate), the species is precautionarily assessed as Critically Endangered under criterion C2a(i).
Assessor/s: Spielmann, A., Costa-Rezende, D.H., Kossmann, T., Drechsler-Santos, E.R. & Gumboski, E.L.; Reviewer/s: Allen, J.; Facilitator(s) and Compiler(s): Leimbach-Maus, H.
Bibliography:
Blanco, O., Crespo, A., Divakar, P.K., Elix, J.A. and Lumbsch, H.T. (2005) Molecular phylogeny of parmotremoid lichens (Ascomycota, Parmeliaceae). Mycologia97(1): 150-159.
Culberson, W.L. & Culberson, C.F. (1981) The genera Cetrariastrum and Concamerella (Parmeliaceae): a chemosystematic synopsis. The Bryologist 84(3): 273-314.
Hale, M.E. (1976) Synopsis of a new lichen genus, Everniastrum Hale (Parmeliaceae). Mycotaxon3(3): 345-353.
Hue, A. (1899) Lichenes extra-Europaei a pluribus collectoribus ad Museum Parisiensi missi. Nouvelles Archives du Muséum d'Histoire Naturelle de Paris4(1): 27-220.
IUCN (2022) The IUCN Red List of Threatened Species. Version 2022-1. Available at: www.iucnredlist.org. (Accessed: 21 July 2022).
Spielmann, A.A. (2006) Checklist of lichens and lichenicolous fungi of Rio Grande do Sul (Brazil). Caderno de Pesquisas Série Biologia18(2): 7-126.
Find out more about the IUCN Red List Categories and Criteriahere.