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Ramalina portosantana Krog

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Scientific name
Ramalina portosantana
Author
Krog
Common names
 
IUCN Specialist Group
Lichens
Kingdom
Fungi
Phylum
Ascomycota
Class
Lecanoromycetes
Order
Lecanorales
Family
Ramalinaceae
Assessment status
Published
Assessment date
2022-02-11
IUCN Red List Category
VU
IUCN Red List Criteria
D1+2
Assessors
André Aptroot (ABL Herbarium, The Netherlands); Paula Matos (Universidade de Lisboa); Laurens Sparrius; Harrie J.M. Sipman; Israel Pérez-Vargas; Alice Gerlach; Maaike Vervoort
Reviewers
Rebecca Yahr

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/70380974/213346631

Justification

Ramalina portosantana is a rock-dwelling species that is narrowly endemic to Porto Santo in the Madeira archipelago where it occurs at three locations. Threats from trampling or wildfire could rapidly impact the whole population. There are only 500–1,000 individuals of this species (Sparrius et al. 2017), thus it is listed as Vulnerable under criteria D1+2.

Taxonomic notes

This is a large, shrubby lichen species growing on volcanic rock. The strap-like thallus is yellowish-green and has a reticulate pattern of ridges, 5-15 cm long. The fruiting bodies are disc-shaped and located on the ends on the straps.

Geographic range

This species is found only on the small island of Porto Santo in the Madeira archipelago, and known only in three locations, each on a separate rock outcrop/volcano, with an area of occupancy of 12 km2.  

Population and Trends

The total population is estimated as 500-1,000 individuals, representing reproductively mature individuals at each site where they have been observed during fieldwork. The numbers are corrected for suitable habitat that could not be reached or visited during the survey (Sparrius et al. 2017).

Population Trend: Unknown

Habitat and Ecology

It is saxicolous, found on basalt volcanic rockfaces at higher elevation. It avoids calcareous rocks, which occur mainly at lower elevations and along the coast, and is found growing together with other endemic macrolichens.

Threats

This species occurs only on one small island. It could be threatened by extinction from wildfire, or trampling (rock climbing, tourism) if development of tourism occurred in the vicinity of the locations. The past impact of these threats has not been documented. Most sites are at quiet places at higher elevation and at some distance from paths and roads.

Conservation Actions

The sites are partially within the Natura 2000 site Pico Branco. The species grows at higher elevations and sites can only be reached by hiking trails. The geology limits development of infrastructure. The rocky cliffs are sparsely vegetated, making them less susceptible to changes in grazing regime and fires.

Source and Citation

Sparrius, L., Aptroot, A., Sipman, H., Pérez-Vargas, I., Matos, P., Gerlach, A. & Vervoort, M. 2024. Ramalina portosantana. The IUCN Red List of Threatened Species 2024: e.T70380974A213346631. Accessed on 23 November 2025.

Country occurrence