Northern Ireland's Priority Species

Saxifraga hirculus – marsh saxifrage

 

Distribution map

Click here to view an interactive map of the Northern Ireland dataset as currently collated by CEDaR.
The map is generated through the NBN Gateway using their Interactive Mapping Tool.

 

Saxifraga hirculus L.
Family: Saxifragaceae

A very rare and local yellow-flowered saxifrage of flushes in mountain bogs or moor; recorded from two distinct areas in County Antrim. It was first found in the county in 1841.

In brief

  • Now only known from one small area on the Garron Plateau
  • Restricted to a flushed site on a hillside covered by blanket peat and heather moor
  • Best seen when in flower (mainly August)
  • Listed as a UK priority species
  • Threatened by habitat degradation and overgrazing.

Species description
This is a perennial herbaceous plant with leafy flowering shoots reaching about 10cm in height. The flowers are about 25mm across, with yellow petals. The leaves are long and narrow.

Life cycle
The flowers are protandrous to promote cross-pollination, which appears to be mainly by Diptera, but it is doubtful that seed set is very high in the Northern Ireland plants because of the tiny size of the population and probably low genetic diversity. The maintenance of the population is most likely by vegetative means — there is no evidence of spread beyond the limited confines of the only known remaining site to others of a seemingly suitable nature nearby.

Similar species
The only other saxifrage with yellow flowers in Northern Ireland is the yellow mountain saxifrage (Saxifraga aizoides), but these two plants do not grow at the same sites. Tiny forms of lesser spearwort (Ranunculus flammula) might be mistaken for the yellow marsh saxifrage at first glance.

How to see this species
The plant has been lost from all sites except one small flushed area on the Garron Plateau, where it flowers mainly in August. It is very difficult to locate this site without assistance. Relevant access permissions should always be sought prior to visiting any sites.

Current status
The yellow marsh saxifrage was formerly known from sites about Lough Naroon and two sites on the Garron Plateau, but since 1955 has been known only from one of its Garron sites. It is protected under the Wildlife Order (NI) 1985.

Why is this species a priority in Northern Ireland?

  • Listed as a UK Priority Species.

Threats/Causes of decline
The causes of the loss of the Lough Naroon sites at some time in the late nineteenth century are unknown — perhaps drainage or habitat degradation. The loss of one of the two Garron Plateau sites after 1920 may be apparent only, that is, the site cannot be identified from the description available. Also the plant cannot be readily identified if nibbled off by grazing sheep.

Over-grazing by sheep may represent the greatest threat to the sole known remaining site.

Conservation of this species

Current action
There is a UK Species Action Plan which was published in 1995.

  • The only site is situated within the Garron Plateau Special Area of Conservation
  • Implementation of the Northern Ireland Habitat Action Plan for Blanket Bog.

Proposed objectives/actions

  • Maintain population at the site
  • Seek to ensure that appropriate levels of grazing are maintained for the benefit of the species
  • Following feasibility assessment and identification of suitable sites, seek to restore populations to sites within the former range
  • Ensure landowners and managers are aware of the presence, legal status and importance of conserving this species, and appropriate methods of habitat management for its conservation
  • Monitor extant populations regularly and seek to identify further threats to the species
  • Survey all former, current and potential sites to confirm the current status of the species
  • Promote ecological research to understand the habitat requirements of this species, particularly the impact of grazing, to underpin management advice and to assess the suitability of this species for reintroduction or translocation.

What you can do
There may be additional unreported sites for this plant in other suitable areas of blanket peat or moorland. Report any finds to The Botanical Society of the British Isles (BSBI), c/o Botany Department, National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU or to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU, Tel: 028 9039 5256, CEDaR.info [at] magni.org.uk.

Further information

Links
Garron Plateau Special Area of Conservation

Northern Ireland Habitat Action Plan, Blanket Bog – April 2003

UK Species Action Plan for Saxifraga hirculus

Literature
Beesley, S. (2006). County Antrim Scarce, Rare and Extinct Vascular Plant Register. Ulster Museum. Belfast.

Hackney, P. (1992). Stewart and Corry’s Flora of the North-east of Ireland, 3rd edn. Inst. Of Irish Studies, Belfast.

Preston, C.D., Pearman, D.A. and Dines, T.D. (2002). New Atlas of the British and Irish Flora. Oxford University Press/DEFRA.

Text written by:
Paul Hackney