Identification Information: Thallus saxicolous, ascending, becoming subpendulous on steep rock faces, rigid, up to 6 cm long, with a number of branches from a holdfast up to 5 mm wide. Branches greyish yellow, sometimes partly pale brown, solid, simple or sparingly branched, subterete or more or less complanate, 1-2 mm wide, tapering gradually towards blunt apices, surface rugulose, with shiny corticate areas interspersed with low, irregularly reticulate ridges which here and there develop pseudocyphellae. Cortex up to 80 umthick, of thick-walled, mainly anticlinal hyphae. Chondroid tissue well-developed, occasionally adjoining the cortex but mostly forming numerous strands embedded in a dense medulla. Soredia absent. Apothecia not seen. Pycnidia mostly with black ostioles. Chemistry (TLC): Salazinic acid, usnic acid (trace).
This macrolichen occurs only on one volcano on a small island. It was described in 1990 by H. Krog and has never been found anywhere else, but is always found by lichenologists visiting its only site. With aseverely restricted range and continuing decline in habitat quality at its single location, it is assessed as Critically Endangered B1ab(i,ii,iii)+2ab(i,ii,iii).
Assessor/s: Aptroot, A. & Thor, G.; Reviewer/s: Scheidegger, C.; Contributor(s): Weerakoon, G. & Perez-Ortega, S.; Facilitator(s) and Compiler(s): Allen, J.
Bibliography:
Aptroot, A. & F. Schumm (2008) Key to Ramalina species known from Atlantic islands, with two newspecies from the Azores. Sauteria15: 21-57.
Krog, H. (1990) New Ramalina species from Porto Santo, Madeira. Lichenologist22: 241-247.
IUCN (2019) The IUCN Red List of Threatened Species. Version 2019-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2019).
IUCN (2020) The IUCN Red List of Threatened Species. Version 2020-2. Available at: www.iucnredlist.org. (Accessed: 13 June 2020).
Sparrius, L.B., Aptroot, A., Sipman, H.J.M., Pérez-Vargas, I., Matos, P., Gerlach, A. & Vervoort, M. (2017) Estimating the population size of the endemic lichens Anzia centrifuga (Parmeliaceae) and Ramalina species (Ramalinaceae) on Porto Santo (Madeira archipelago). The Bryologist120(3), 293-301.
Find out more about the IUCN Red List Categories and Criteriahere.