• 1Proposed
  • 2Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Caloplaca rinodinae-albae Poelt & Nimis

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Scientific name
Caloplaca rinodinae-albae
Poelt & Nimis
Common names
IUCN Specialist Group
Assessment status
IUCN Red List Category
Proposed by
Sonia Ravera
Sonia Ravera
Comments etc.
Anders Dahlberg

Assessment Notes

Taxonomic notes

The species is easy to recognize in the field by specialist lichenologists by its parasitic growth on Rinodina alba Arnold. The species’ taxonomy is well defined. The species grows over rocks, its growth in isolated patches on the host suggests obligate parasitism. The thallus is rounded up to 8 cm in diameter, sometimes thalli confluent forming larger patches; the colour is pale orange. Apothecia are sparse or clustered to 1 mm diam., lecanorine with a plane disc red-orange. It is characterized by thick swollen cells of the paraphyses and the broadly elliptical to globose spores.

Why suggested for a Global Red List Assessment?

The global distribution of this species is limited to only one locations in Sardinia (Italy) with an area of occupancy (AOO) of 0,432 km².
Criterion A: There are no reports about the trends of population size over long time periods, so it is not possible to apply this criterion.
Criterion B: Criterion B2 could be applied as the area of occupancy (AOO) is <10 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.

Geographic range

This species occurs only with one small subpopulations on the little island Isola dei cavoli (Sardinia, Italy).

Population and Trends

The species is restricted to steep north facing slopes. Population size was not assessed.

Population Trend: Uncertain

Habitat and Ecology

Parasitic on Rinodina alba Arnold, the species grows on sun-exsopsed rocks.

Sea Cliffs and Rocky Offshore Islands


This species occurs only on one island. It could be threatened by accidental extinction from tourism or fire, if development of tourism occurred in the vicinity of the population.

Recreational activities

Conservation Actions

The location is within the borders of a protected area.
No conservation plan is available.

Research needed

There is an urgent need for a detailed assessment of population size, the extent of occurrence and trend. 

Population size, distribution & trends

Use and Trade


Nimis P.L., Poelt J., 1987. The lichens and lichenicolous fungi of Sardinia (Italy). An annotated list.Studia Geobotanica 7,
Nimis P.L., Martellos S., 2008: ITALIC - The Information System on Italian Lichens. Version 4.0. University of Trieste, Dept. of Biology, IN4.0/1 (http://dbiodbs.univ.trieste.it/).

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted