Taxonomy

Sphagnum tenellum | Soft 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.

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

IUCN Conservation Status
Ireland (1)Least Concern
Europe (2)Not evaluated
Global (2)Not evaluated

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, 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.
  • 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 tenellum is one of a group of 6 Irish Sphagnum species that are often referred to collectively as section Cuspidata.

In this group the defining characteristics are primarily microscopic however there are other characteristics that may aid identification in the field.

  • Branch leaves are not conspicuously hooded at the apex.
  • Branch leaves not noticably toothed at edges.
  • Stem cortex makes up rather less than 1/4 of the stem diameter.
  • Stem leaves usually with a distinct border to the base.
  • Stem leaves may be appressed and orientated so the apex points down and away from  the capitulum, or may spread at an angle to the stem.
  • In some species ( bit not S. tenellum) branch leaves markedly alter appearance when dry, spreading at various degrees away from the branch.

In addition to most of the characteristics outlined above Sphagnum tenellum is distinctive for being the smallest of the Sphagnum species found in Ireland.

  • S. tenellum may vary in colour from yellow-orange  to a mix of green and yellow-orange or just green if submerged for long periods. S. tenellum usually occurs as low hummocks or mats or as separated groups of stems.
  • In good growing conditions S. tenellum will generally be under 1cm in diameter including fascicles.
  • S. tenellum also has very short branches, mostly under 10mm and often under 8mm in length.
  • Stem leaves are to a maximum of 1.4mm long and 0.7mm wide, but even when less than this, they can appear large relative to the overall size of the plant.
  • Stem leaves tongue shaped and may be slightly hooded at the tip.
  • Stem leaves spread from the stem.
  • Stems usually green.
  • Branch leaves are quite concave. and ovate and similar in length to stem leaves.
  • In S. tenellum, branch leaves do not markedly alter their degree of spread from the branch when dry.
  • Capitulum not as strongly defined as in other Sphagnum species.
  • S. tenellum has 2 spreading branches and 1 pendent branch although branch types not very different in appearance.
  • Pairs of leaves at the tip of some of the spreading branches may diverge, giving the appearance of a very small claw a the tip of those branches.
  • S. tenellum is surprsingly fragile for a Sphagnum and may easily fall apart while being examined.
  • Well grown shoots to only 10cms in height.

  • Capsules are frequent in the summer.

Sources: Atherton, I., Bosanquet, S., Lawley, M.,  2010; Lockhart, N., Hodgetts, N. & Holyoak, D. 2012a; Smith, A.J.E. 2004; Frey, W. et al 2006.

Adult habitat & habits


Habitat

A species very much associated with more acidic habitats.

Habitats may include but are not necessarily limited to;

  • Bogs (PB)
  • Poor fen and flush (PF2)
  • Wet Heath (HH3)
  • Montane Heath (HH4)
Sources: Atherton, I., Bosanquet, S., Lawley, M.,  2010; Rodwell, J.S. (ed.) 1991;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

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.

Distribution

World distribution(GBIF)

Mainly north hemisphere, and mainly in areas adjacent to oceans. Most European records from Ireland and Britain, Sweden, Norway, Denmark, the Netherlands. Records also from mountainous areas of central Europe and northern Iberia as well as southern Iceland and Greenland.

Records from eastern and western seaboards of North America as well as from central America and the north west of South America. Records also from Japan. In Hill M.O. et al (1992) reference is made to records from Kamchatka in the north eastern Russia.

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

As a species more likely to be found in areas of high rainfall, it is perhaps unsurprising that S. tenellum is widepread in Ireland, but perhaps less common in the south and east. It is common in suitable habitat.

Temporal change

Records submitted to Data Centre in 2019

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 tenellum 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., 1992. Sphagnum: A Field Guide, Revised by Hodgetts, N.G. & Payne, A.G., ISBN 1 87370 114 4

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 10 December 2014.