Cladonia portentosa



Conservation status

Future ProspectsN/A
Overall  Assessment of Conservation StatusInadequate
Overall Trend in Conservation StatusStable
*A particular subset of Cladonia species, the subgenus Cladina, is identified as requiring assessment under the Habitats Directive. Guidelines on reporting for the Habitats Directive indicate that these species are required to be reported on as a group, unless a member state is of the opinion that individual species within the group may require special attention. In the Article 17 Habitats Directive reporting for the period 2007-2012 none of the Cladonia species of the Habitats Directive occurring in Ireland were identified as requiring special attention.

The Conservation Status in the table above is then for the entire subgenus Cladina as found in Ireland rather than for the individual species.

Source: NPWS 2013; European Topic Centre on Biological Diversity.

IUCN Conservation Status
Not evaluated
Europe (1)
Not evaluated
Global (1)Not evaluated

Source: (1) The IUCN Red List of Threatened Species. Version 2014.2 2014.

There is no current, published, IUCN Red Data List for Irish lichen species. While the conservation status of individual lichen species in Ireland can not be inferred from their status in Wales or England, the results of recent assessments within those jurisdictions are provided here for information.

In both the 2012 Conservation Evaluation of British Lichens and Lichenicolous Fungi, and the 2010 Lichen Red Data List for Wales Cladonia portentosa is listed as Least Concern.

Sources: Woods, R. G. 2010; Woods, R.G. & Coppins, B. J. 2012

Legal status

Protected by the following legal instruments:

  • Habitats Directive [92/42/EEC] Annex V

Native status


Species Biology


The species in Cladonia subgenus Cladina are popularly known as 'reindeer moss', and these species are the much branched lichens that in Ireland are often found as balls, tufts or mats among low vegetation such as heather on blanket bogs, raised bogs and heaths or for some species among vegetation on dunes.

Although the morphology of the subgenus is distinctive, identification to species or variety level can be difficult and may involve microscopic examination and the use of chemicals in order to be certain.

In subgenus Cladina the distinctive branched, fruticose (tree- or shrub-like) growth form is preceded by a crustose stage from which the hollow, branched podetia develop. This crustose stage does not persist after the podetia have been formed.

Brown apothecia, when formed, are found at the apices of podetia.

Apart from the characteristics mentioned above, Cladonia portentosa also has the following characteristics;

  • Ultimate branching of podetia up to three times.
  • Overall branching is rather coarser than in other species e.g. Cladonia azorica.

  • Podetia may grow up to 10cm in height.
  • Colouration may be from grey-green to a yellow-green.
  • Ultimate branchlet tips are not strongly oriented in one direction.
  • Branch axils are often perforated.

  • Pycnidial jelly is colourless.

Chemical reactions:

  • K-    (Potassium hydroxide negative)
  • C-    (Sodium hypochlorite negative)
  • KC+ (Potassium hydroxide, followed by Sodium hypochlorite positive reaction giving yellow colour)
  • P-    (Paraphenylenediamine [caution-caracinogenic] negative)
Examination of the medulla under UV light gives a pale blue fluorescence.

Sources: Smith C. W. et al 2009; Dobson Frank S. 2005.


Habitats may include but are not necessarily limited to;

  • Wet heath (HH3)
  • Montane Heath (HH4)
  • Bogs (PB)
  • Bog woodland (WN7)

  • Fixed dunes (CD3)

Sources: NPWS 2007 (a&b); Dobson Frank S. 2005; Fossitt, J.A. 2001.


Lichens are a mutualistic association between a fungal and algal partner and lichens do not reproduce sexually as such, however the lichenized fungal partner may do so.

In lichenized fungi the organs involved in reproduction are the same as in the non-lichenized forms of the fungi.

For Cladonia species the fungal partner is an ascomycete fungus. In these fungi the fruiting body in which spores are produced sexually is termed an apothecium. On dispersal the haploid 'ascospores', in order to produce another lichen, will need to come in contact with a suitable algal partner.

Asexually produced spores are produced in a flask-like structure, a pycnidium. When present these are located at the tips of podetia of lichens in Cladonia subgenus Cladina.

For species in Cladonia subgenus Cladina with many delicate, protruding branches fragmention provides a useful vegetative method of asexual reproduction.

Sources: Whelan, Paul 2011; Smith C. W. et al 2009.

Threats faced

In the Article 17 Habitats Directive reporting for the period 2007-2012 no current threats were listed for this species. In that reporting period the named Cladonia species of the Habitats Directive occurring in Ireland were given an 'Overall Assessment of Conservation Status' of 'Inadequate' due to;

  • Ongoing pressures on the habitats where they occur.
Source: NPWS 2013.

Conservation actions

In the Article 17 Habitats Directive reporting for the period 2007-2012 no Conservation Measures in place or in the process of being implemented during the period were listed for this species.

Source: NPWS 2013.


World distribution(GBIF)

Records for this subspecies appear concentrated in Britain and Ireland, the Netherlands, Denmark, the West Coast of Sweden. Scattered records from the rest of western Europe. Records also from the Canary Islands, Cameroon and South Africa.

There is another concentration of records on the west coast of North America from northern California to British Columbia and across the Aleutian Island chain, with a very few records from the eastern seaboard of North America.

Accuracy of world distribution shown in the Global Biodiversity Information Facility (GBIF) map below will be constrained by, amongst other factors, data held but not shared by countries and organizations not participating in the GBIF.

Irish distribution

Recorded from every vice-county on the island.

Source: Seaward M.R.D., 2010.

Temporal change

Records submitted to Data Centre in 2022

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

The National Biodiversity Data Centre is trying to improve our knowledge of the distribution of Cladonia portentosa in Ireland. Should you observe this species, please submit sightings to add to the database. Detailed observations will assist us gaining a better insight into where the species is most abundant in Ireland and we might also be able to detect regional variations. Please submit any sightings and photographs at:

All records submitted online can be viewed on Google Maps – once checked and validated these will be added to the database and made available for conservation and research.

Further information

For further information contact Dr. Liam Lysaght



Dobson Frank S.  Lichens: An Illustrated Guide to the British and Irish Species 2005. Richmond Press, Slough

NPWS (2013) The Status of EU Protected Habitats and Species in Ireland.  Species Assessments Volume 3. Version 1.0. Unpublished Report, National Parks & Wildlife Services. Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland

NPWS (2007a) The Status of EU Protected Habitats and Species in Ireland. Backing Documents, Article 17 forms, Maps. Volume 3

NPWS (2007b) The Status of EU Protected Habitats and Species in Ireland. Backing Documents, Article 17 forms, Maps. Volume 1

Seaward M.R.D.2010 Census Catalogue of Irish Lichens (3rd Edition).  National Museums of Nothern Ireland.

eds. Smith C. W., Aptroot A., Coppins B. J., Fletcher A., Gilbert O. L., James P. W. and Wolseley P. A. (2009). The Lichens of Great Britain and Ireland. The British Lichen Society, London.

Woods, R. G. (2010) A Lichen Red Data List for Wales, Plantlife, Salisbury.

Woods, R.G. & Coppins, B. J. 2012. A Conservation Evaluation of British Lichens and Lichenicolous Fungi. Species Status 13. Joint Nature Conservation Committee, Peterborough