The species is well characterized by its saxicolous habit, umbilicate foliose thallus up to 12 cm diam. Upper surface is whitish to creamish grey, lower surface is dark brown to black with abundant rhizinomorphs, more or less branched. Apothecia with gyrose discs.
This is a well-known macrolichen that is only known from a few mountains in France and Spain. The genus is relatively well-known and is often collected, but this species was never found elsewhere. Species of the family Umbilicariaceae are often long-lived, and have a long generation time (in the order of magnitude of a century), and apothecia rarely contain viable ascospores. The chance that such a species with a very restricted range becomes accidentally extinct before being able to relocate to another place is very high. This species may be doomed already.
Criterion A: It does not apply as no population trends are known for the species, nor in the past neither inferred for the future.
Criterion B: Although the area of occupancy is likely less than 2000 km2, number of locations is higher than 10 and no decline or extreme fluctuations of populations have been oberved or estimated. This criterion does not apply.
Criterion C: No information about the actual number of individuals is known. This criterion does not apply.
Criterion D: The estimated total surface area globally <500 m2 (D. Mason, pers. comm, separate e-mail from 3 Feb 2015). Would qualify for VU D1 according to absolute estimated population size following criterion for saxicolous lichens of 1 individual = 1 m2 of occupied rock surface.
The species has been evaluated as Vulnerable according to criterion D1.
he species is currently known from 25 localities, 6 from Aigoual massif and 19 from central and eastern Pyrenees (cf. attached > map) (Didier Mason, pers. comm. by e-mail). The species is also known from the Spanish Pyrenees (Llimona 1991).
The total population is not exactly known but it is in the order of a square decameters, certainly below several square decameters. Not all stands may be accessible to man. Those that are suffer from collecting and trampling.
Population Trend: Deteriorating
Saxicolous in vertical or very steep surfaces, on acidic rocks, especially non calcareous schists. In humid or subhumid areas. Member of the Umbilicarion hirsutae.
Accesible stands suffer from trampling by climbers and from collecting by naturalists and lichenologists.
Accession to stands that are in view for the public should be made impossible. The species should be illustrated on park leaflets, dissueding people to collect these very old and slow-growing organisms with a very narrow distribution range.
The actual population sizes should be investigated and well as genetic connectivity and isolation of current populations.
Frey, E 1936: Vorarbeiten zu einer Monographie der Umbilicariaceen. - Berichte der schweizerischen botanischen Gesellschaft 45: 198-230.
Llimona, X. 1991 - Historia Natural dels Països Catalans. Vol. 5: Fongs i Líquens - Enciclopèdia Catalana, Barcelona.