Identification Information: A macrolichen that is recognizeable also to non-specialists. Thallus saxicolous, opaque, pale green-grey, up to I cm high, forming dense. compacted, irregularly spreading colonies without a distinct. delimited holdfast. Laciniae fragile. simple or sparingly branched, up to I mm broad. fistulose, at first more or less terete, but soon flattening as the lower tissue layers split open almost to the base. exposing the medulla. Apices often revolute. Soredia absent. Cortex indistinct, chondroid tissue of uneven thickness, medulla dense. Apothecia and pycnidia not seen. TLC: divaricatic acid & usnic acid (+/-).
This macrolichen belongs to a genus with (for fungi) surprisingly many species with narrow distributions. This species is only known from two volcanoes on the small island of Porto Santo. Described in 1980 and never found anywhere else, but always observed by lichenologists visiting the type locality. Criterion A: There is not enough information to assess against this criterion. Criterion B: There is not enough information to assess against this criterion. Criterion C: There is not enough information to assess against this criterion. Criterion D: There are less than 250 individuals estimated, this has been calculated using the definition that 1 individual = 1 m² (see Guideline drafts for fungal red-listing 20140415), fulfilling criteria of D1; AOO is less than 20 km² and number of locations is 1.
Assessor/s: Aptroot, A. & Thor, G.; Reviewer/s: Scheidegger, C.; Contributor(s): Weerakoon, G. & Spribille, T.
Bibliography:
Aptroot, A. & Schumm, F. (2008) Key to Ramalina species known from Atlantic islands, with two new species from the Azores. Sauteria15: 21-57.
IUCN (2018) The IUCN Red List of Threatened Species. Version 2018-2. Available at: www.iucnredlist.org. (Accessed: 15 November 2018).
Krog, H. & Oesthagen, H. (1980) Two new Ramalina species from Porto Santo, the Madeira Islands. Norwegian journal of Botany27: 185-188.
Sérusiaux, E. (1989) Liste Rouge des macrolichen dans la Communauté Europeenne. Département de Botanique, Liège.
Sparrius, L.B. et al. (2017) Estimating the population size of the endemic lichens Anzia centrifuga (Parmeliaceae) and Ramalina species (Ramalinaceae) on Porto Santo (Madeira archipelago). The Bryologist119 (in press).
Find out more about the IUCN Red List Categories and Criteriahere.