Taxonomy

Sphagnum strictum | Pale Bog-moss

Distribution

Status

Conservation status

HABITATS DIRECTIVE ARTICLE 17 REPORTING*
RangeN/A
PopulationN/A
HabitatN/A
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)Data deficient
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

Native.

Species Biology

Identification

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
  • 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.
  • Rather than the seta (stalk) seen in other mosses, in Sphagnum species the spore bearing capsule is borne on a pseudopodium.
  • 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 strictum is one of two Sphagnum  species (the other is Sphagnum compactum) that are referred to collectively as section Rigida. Characteristics that may aid identification in the field are;

  • Branch leaves are not very conspicuously hooded at the apex.
  • Stem cortex makes up less than 1/4 of the stem diameter.
  • Stem leaves, apart perhaps from compact forms, are oriented with the apex pointing away from capitulum.
  • Stem leaves are very small actually and in comparison to branch leaves.

  • When branches are dense and erect these two species might be overlooked as non-sphagnum species.
  • Pendent and spreading branches are very different

Within this section Sphagnum strictum leaves are usually a pale, almost whitish green, sometimes with hints of peach or tan.

  • Stem leaves are very small (to 0.7mm in length) and triangular.
  • Stems are green, or a very pale brown.
  • Branch leaves (to 2.7mm in length) are ovate, but tapering to the apex which is truncate and bears small teeth.
  • Branch leaves are generally curved away from branch stem, giving a slightly 'spiky' look.
  • S. strictum has 2 to 3 spreading branches and 1 to 3 hanging branches.
  • Spreading branches are distinctly more robust than pendent branches.
  • Well grown shoots to 15cm long.
  • Capsules are frequent in the summer.
  • Grows in looser mats or patches than S. compactum and individual capitula more easily distinguished.

Sources: Atherton, I., Bosanquet, S., Lawley, M.,  2010; Lockhart, N., Hodgetts, N. & Holyoak, D. 2012a; Smith, A.J.E. 2004.

Habitat

There appears to be quite a strong association between Sphagnum strictum and the grass species Molinia caerulea in some of the habitats listed below.

Habitats may include but are not necessarily limited to;

  • Upland Blanket bog (PB2)
  • Lowland Blanket Bog (PB3)
  • Wet Heath (HH3)
  • Exposed Siliceous rock (ER1)

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

Reproduction

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.

Rare and Threatened Bryopthytes of Ireland list threats such as;

  • Drainage
  • Afforestation
  • Peat cutting
  • Wetland reclamation

Source: Lockhart, N. et al 2012a.

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.

While no Conservation Actions are listed in Rare and Threatened Bryopthytes of Ireland, or in the 2012 Irish Bryophyte Red List, it is suggested that in order to proerly assess the Conservation status of Sphagnum strictum it is necessary that there be;

  • Research on population size, distribution and trends.
Sources: Lockhart, N. et al 2012; Lockhart, N. et al 2012a.

Distribution

World distribution(GBIF)

In Europe, Sphagnum strictum is most recorded in Norway, Britain (particularly Scotland) and Ireland, with records also from Iceland, Sweden and Denmark.

In Hill et al (1992) rare records from Switzerland and Germany are mentioned.

Scarce records also from North Amercia, South America, Africa and Papua New Guinea.

In Hill et al (1992) records from Madagascar and south-east Asia are mentioned.

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

It is generally rare in Ireland and Britain apart from areas of high rainfall.

Source: Atherton, I., Bosanquet, S., Lawley, M., 2010.

Records for Ireland indicate a particularly western and northern distribution.

Temporal change

Records submitted to Data Centre in 2024

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 strictum 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:

http://records.biodiversityireland.ie/

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 llysaght@biodiversityireland.ie

References

Publications

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. <www.iucnredlist.org>. Downloaded on 21 November 2014

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