Taxonomic Source(s): Haugan, R. (1992) Anzia centrifuga, a new lichen species from Porto Santo, Madeira. Mycotaxon44(1):45-50.
Taxonomic Notes: The species is easy to recognize in the field by specialist lichenologists. The species' taxonomy is well defined and it is the only species of this genus in Macaronesia. The species grows over rocks, is adnate to loosely attached to the substrate. The thallus is orbicular up to 30 cm in diameter, dying at the center of the thallus; the colour is pale grey. The thallus has numerous apothecia. Lobes are 1-2 mm wide, dichotomously branched, more or less imbricate, lobe tips showing calcium oxalate deposits. The medulla has a chondroid axis. The lower side is with a felt like layer of short rhizines characteristic of this genus. Secondary metabolites include atranorin and several unknown terpenoids.
This species occurs only with two small subpopulations on one volcano. It is threatened by accidental extinction from trampling, grazing and possibly collecting.
Criterion A: There are no reports about the trends of population size over long time periods, so it is notpossible to apply this criterion.
Criterion B: Both B1 and B2 could be applied as the extent of occurrence (EOO) is 10 km2 and the area ofoccupancy (AOO) is 1 km2. However, the species does not fit the condition of also meeting two subcriteria. It only fits B1a or B2a as there is a single location. However no information is available regarding continuing declines and extreme fluctuations.
Criterion C: No information is available about the total number of individuals of this species. Thus, subcriteria C1 and C2 are not applicable.
Criterion D: The total number of individuals is unknown but the area of occupancy (AOO) is smaller than 20 km2 and the number of locations is one. Development of tourism is a plausible threat to this species. Therefore, it qualifies for Vulnerable D2.
Criterion E: No quantitative analyses have been carried out.
The species is assessed as VU D2 until more research on the species, particularly the population size, is carried out.
Assessor/s: Aptroot, A., Perez-Ortega, S & Scheidegger, C.; Reviewer/s: Dahlberg, A. & Nimis, P.L.
Bibliography:
Haugan, R. (1992) Anzia centrifuga, a new lichen species from Porto Santo, Madeira. Mycotaxon44(1): 45-50.
IUCN (2014) The IUCN Red List of Threatened Species. Version 2014.3. Available at: www.iucnredlist.org. (Accessed: 13 November 2014).
Jayalal U., Wolseley P., Gueidan C. C., Aptroot A., Wijesundara S. & Karunaratne V. (2012) Anzia mahaeliyensis and Anzia flavotenuis, two new lichen species from Sri Lanka. The Lichenologist 44: 381-389.
Find out more about the IUCN Red List Categories and Criteriahere.