Sphagnum girgensohnii | Girgensohn's Bog-moss



Conservation status

Future ProspectsN/A
Overall  Assessment of Conservation StatusInadequate
Overall Trend in Conservation StatusStable
*All E.U. Sphagnum species  are 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 named Sphagnum 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 Sphagnum genus in Ireland rather than for the individual species.

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

IUCN Conservation Status
Ireland (1)Near Threatened
Europe (2)**Not evaluated
Global (2)Not evaluated

*Although not published separately, an evaluation of 'Least Concern' at a European level is indicated in the Ireland Red List No.8: Bryophytes. This evaluation was carried out under the auspices of the European Committee for Conservation of Bryophytes.

Sources: (1) Lockhart, N., Hodgetts, N. & Holyoak, D. 2012; (2) The IUCN Red List of Threatened Species. Version 2014.3.

Legal status

Protected by the following legal instruments:

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

Native status


Species Biology


Members of the Sphagnum genus are distinguished from other moss species by the combination of the following, amongst other, characteristics;

  • The absence of rhizoids in the gametophyte, and the presence of groups of spreading and / or pendent branches (these groups referred to as fascicles) arranged at intervals along the main stem.
  • As well as chlorophyllose cells (chlorocysts) Sphagnum leaves have adapted large dead cells, 'hyaline' cells, that allow Sphagnum species plants to retain water in relatively large amounts.
  • The sporangium lacks the peristome seen in many other moss genera.
  • The top end of the plant, where new fascicles are formed, contain many young compact fascicles which give Sphagnum species a distintive 'mop-head' look. This terminal head is termed a capitulum.
  • The lack of a leaf mid-rib or 'costa'.

Sphagnum girgensohnii is one of a group of twelve Irish Sphagnum taxa (including 4 subspecies) that are often referred to collectively as section Acutifolia. In this group the defining characteristics are primarily microscopic e.g. that branch leaves have up to 3 large pores (between 8µm and 30µm) on the underside, and that chlorocyst shape is approximately triangular, the base of the triangle most visible from the upperside of branch leaves.

There are other characteristics that may aid identification in the field.

  • Branch leaves are not conspicuously hooded at the apex.
  • Stem cortex makes up less than 1/4 of the stem diameter.

  • Stem leaves, depending on species and / or conditions will have patches of narrow cells in the angles at the base of the leaves across between 20% and 80% of the width of the leaf base (apart from Sphagnum molle where these patches are absent).

  • All species in this section (apart from Sphagnum molle) have stem leaves appressed with the leaf apex directed towards the capitulum in normal growing conditions.
Within this section Sphagnum girgensohnii is green with no trace of red colour on stem or leaves.

  •  Stem leaves are lingulate i.e. rather tongue shaped, with parallel sides.
  • These stem leaves have a tattered fringe toward the centre of the top edge only, although sometimes the fringing may be absent entirely, or a notch may replace the fringing.

  • The stem leaves may also often have a brown staining in cells at corner angles of the leaf base.
  • Branch leaves are ovate.
  • Viewed from above, the capitulum is more often than not distinctly star shaped, although this is not so noticable in compact forms in exposed sites. Single developing branches may be seen between the rays of the ''star'.
  • The terminal bud at the centre of the capitulum does not appear large in comparison to overall capitulum width, although it is readily distinguishable by eye.
  • Stem is usually quite stiff by comparison with S. fimbriatum, and will stay upright if held up between thumb and forefinger (however S. teres can also appear 'stiff' however it has stem leaves oriented in different directions and will most usually have some ginger colouration and does not have 'tattered' leaf apex.).

  • S.girgensohnii has 2 or 3 spreading branches and 1 or 2 pendent branches.
  • Well grown shoots to 20cm long.
  • Capsules rare, when developed, they are found in Summer.
Sources: Atherton, I., Bosanquet, S., Lawley, M.,  2010; Lockhart, N., Hodgetts, N. & Holyoak, D. 2012a; Smith, A.J.E. 2004


Associated with more base rich environments, or at least base rich flushes in otherwise base poor environments. Particularly at low altitudes it is a shade loving species, and may occur on shaded banks or rocks within habitats and may be more likely to occur on northern or eastern facing slopes at higher altitudes.

Habitats may include but are not necessarily limited to;

  • Upland blanket bog (PB1)
  • Poor fen and flush (PF2)
  • Transition mire and quaking bog (PF3)
  • Wet heath (HH3)
  • Montane heath (HH4)
  • Oak-birch-holly woodland (WN1) particularly damp, peaty hollows within this habitat
  • Wet pedunculate oak-ash woodland (WN4)
  • Bog woodland (WN7)
  • Highly modified / non-native woodland (WD) On wet or flushed moderately nutrient enriched to acid soils.

Sources: Atherton, I., Bosanquet, S., Lawley, M.,  2010; Rodwell, J.S. (ed.) 1991; Hill, M.O. et al 1992; Fossitt, J.A. 2001.


Classic alternation of generations with diploid sporophyte and haploid gametophyte generations. In mosses the haploid gametophyte is the longer lived and obvious plant seen in the field.

The sporophyte is the capsule which is borne on a pseudopodium produced from tissue of the gametophyte.

Fertilization of female gametes by male gametes produces the diploid sporophyte. Meiosis of spore mother cells produce haploid spores, which are disseminated when the capsule opens. Spores germinate into a filamentous 'protonema' which will eventually produce the familiar moss gametophyte.

Sources: Porley, R. Hodgetts N. 2005.

Sphagnum species can also spread vegetatively through the development of new stems from branches and may also spread via plant fragments.

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 Sphagnum species of the Habitats Directive occurring in Ireland were given an 'Overall Assessment of Conservation Status' of 'Inadequate' due to;

  • 'The poor conservation status of the peatland habitats within which the majority of Sphagnum species 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)

Northern hemisphere, boreal but extending to the arctic and also into temperate zones.

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

Records are scattered, but not very frequent on the island as a whole.

Temporal change

Records submitted to Data Centre in 2020

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 Sphagnum girgensohnii 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



Atherton, I., Bosanquet, S., Lawley, M.,  2010. Mosses and Liverworts of Britain and Ireland a field guide. British Bryological Society.

Fossitt, J.A. 2001 A Guide to Habitats in Ireland. The Heritage Council.

Frey, W.,  Frahm, J.P., Fischer E., and Lobin W. 2006.  The Liverworts, Mosses and Ferns of Europe. Harley Books, Colchester.

Hill, M.O., Preston C.D., and Smith A.J.E., 1992. Atlas of the Bryophytes of Britain and Ireland Vol. 2 Mosses (except Diplolepideae). Harley Books, Colchester.

Holyoak, D. T. (ed.). 2003. The distribution of bryophytes in Ireland: An annotated review of the occurrence of liverworts and mosses in the Irish vice-counties baseed mainly on the records of the British Bryological Society. Broadleaf Books, Wales.

Lockhart, N., Hodgetts, N. & Holyoak, D. 2012. Ireland Red List No.8: Bryophytes. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.

Lockhart, N., Hodgetts, N. & Holyoak, D. (2012a) Rare and Threatened Bryophytes of Ireland. National Museums of Northern Ireland.

Porley, R. and Hodgetts N. 2005 Mosses & Liverworts, Collins.

Rodwell, J.S. (ed.) 1991. British Plant Communities Vol.2 Mires and Heaths.Cambridge University Press.

Smith, A.J.E. 2004. The Moss Flora of Britain. Cambridge University Press.

The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 19 November 2014