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Ramalina timdaliana Krog

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Scientific name
Ramalina timdaliana
Common names
IUCN Specialist Group
Assessment status
Assessment date
IUCN Red List Category
IUCN Red List Criteria
Perez-Ortega, S.
Scheidegger, C.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/70384543/70384546


There only exists a single small population on one volcano mountain in the world. It is threatened by accidental extinction by trampling, grazing and possibly collecting.

Criterion A:  There is no current information about the trends of population size over long time periods, so it is not possible to apply this criterion.

Criterion B: Both B1 and B2 subcriteria could be applied as the extent of occurrence is smaller than 100 km² and the area of occupancy is likely smaller than 10 km². However, the species does not fit the two necessary conditions for this criterium. It only satisfy subcriterion B1a (or B2a) as it occurs in a single population worldwide. However, no available information support the application of subcriteria a or b.
Criterion C. No information is available about the total number of individuals of this species. 
Criterion D. The total number of individuals is unknown, considering 1m²= 1 ind, it is likely the number of individuals is less than 250. Actually 250 m² is occupied by the species, which is known from a single mountain top. 

Taxonomic notes

This is shrubby species growing saxicolous on volcanic rocks. It stands up to 5 cm high, and it adheres to the substrate surface through a holdfast 2-4 mm diam. It is richly branched. Branches are solid, subterete to somewhat complanate, 0-8-1-2(-2) mm wide, often with shortly linear pseudocyphellae, especially near the base, apices with several branching points close together. Soredia absent. Cortex c. 25 um thick, chondroid tissue forming a discontinuous cylinder with a few chondroid strands interconnected across the medulla. Apothecia numerous, lateral, up to 3 mm diam.; spores (few seen) bilocular,
13-14x6 um. Chemistry: Divaricatic acid, triterpenoids, usnic acid. The species belongs to the Ramalina decipiens group (Krog & Osthagen 1980), a group of Macaronesian endemic species.
The species is very morphologically very similar to the also endemic R. jamesii. Main differences are anatomical and chemical. Chondroid tissue is discontinous in R. timdaliana and continuous in R. jamesii filling most of the branches.  Further, different terpenoid patterns are found in both species and salazinic acid is only found in R. jamesii.

Geographic range

The species is known from a single peak -old volcano- Pico do Castello on the small Island of Porto Santo in the Madeira Archipelago (Portugal). This peak also hosts other endemic Ramalina species also assessed as R. erosa, R. confertula, R. jamesii and the recently IUCN red listed species Anzia centrifuga.

Population and Trends

The species is restricted to one locality on a volcano. Population size was not assessed. Population size is, considering 1 individual =1 m², likely to be less than 250 individuals.

Population Trend: unknown

Habitat and Ecology

Saxicolous, on volcanic acidic rocks. During a visit to Pico do Castelo in May 2015, specimens that seem to belong to this species were also found on dry branches of living and dead Pinus halepensis (Sparrius et al. 2017)


The most important threats are related to its small population size, and its single island endemic character. Due to the small population size there is a high risk of extinction due to single catastrophic event such as a fire.
It is very likely that the species may be grazed by goats during dry periods as it occurs with other Ramalina species in the Macaronesia.
There is also a high risk of population reduction due to collection by lichenologists.
Finally, trampling by touristic activities may represent a risk for this species.

Conservation Actions

The most important action to be taken is the whole protection of the area where this and other threatened species occur.
Urgent need to establish the actual population size as well as population dynamics. Research on the biology of the species (reproduction, generation time,...) is also needed. Phylogenetic studies to infer its phylogenetic affinities are being carried out.

Source and Citation

Perez-Ortega, S. 2017. Ramalina timdaliana. The IUCN Red List of Threatened Species 2017: e.T70384543A70384546. https://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T70384543A70384546.en .Accessed on 6 February 2024

Country occurrence