Northern Ireland's Priority Species

Cochlearia officinalis subsp. scotica – scottish scurvy-grass

 

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.

 

Cochlearia officinalis subsp. scotica (Druce) P.S. Wyse Jacks.
Family: Brassicaceae

In most ways this is a small form of the common scurvy-grass (Cochlearia officinalis) but is regarded by many botanists as sufficiently distinct to justify it being treated as a separate species or subspecies. It is endemic to Great Britain and Ireland.

In brief

  • Found in coastal areas in Counties Antrim and Down

  • Widely distributed on rocks and dry ground by the sea

  • Flowers from April to June

  • Listed as a UK Priority Species

  • Main threats are coastal development

  • Taxonomic status is uncertain.

Species description
A biennial or perennial herbaceous species with a low rosette or tuft of long-stalked leaves, the leaf blade being kidney-shaped or roughly triangular. The flowering stems also tend to lie flat against the rock or soil. The stems have leaves which are unstalked, and the flowers are small, with four white or pale mauve petals. The general appearance and form of the plant is like a miniature of common scurvy-grass (Cochlearia officinalis) with which it usually grows.

Life cycle
The flowers are probably insect-pollinated and are succeeded by the fruits which are oval, flattened pod-like structures called siliquas. The seeds within are released by the fruits splitting. Germination of the seed produces a non-flowering rosette in the first year, followed by the plant flowering in the second year. Some individuals may be short-lived perennials which continue to flower for several seasons, but the precise details of the life cycle have not been the subject of detailed study in Ireland.

Similar species
Common scurvy-grass is similar but larger in all parts, including the seeds.

How to see this species
This plant has only been recorded rarely in recent years but may be a lot commoner than such lack of records suggest. Look for it on rocky outcrops close to the sea in Counties Antrim and Down from April to June. The most recent reports (from 2000 onwards) come from the County Down coast south of Newcastle and from Whitepark Bay in County Antrim. Relevant access permissions should always be sought prior to visiting any sites.

Current status
Problems arise in assessing the distribution or abundance of this plant because it is unclear if it is a separate species, that is, really distinct from common scurvy-grass. This has led many botanists to ignore recording it and thus giving rise to the view that it is rare and declining.

Why is this species a priority in Northern Ireland?

  • Listed as a UK priority species which appears to be endemic to Great Britain and Ireland

  • This species is also rare.

Threats/Causes of decline
The decline of this species may be apparent only, resulting from a lack of conviction by modern field recorders that this is a valid species. This accords with the position reported in the UK Biodiveristy Action Plan. The only threat to the loss of this species would appear to be coastal devlopment and an attendant loss of habitat, but this has been insufficient to account for any decline in Northern Ireland.

Conservation of this species

Current action

  • Some of its sites are designated as ASSIs

  • At least two sites are managed by the National Trust

  • Implementation of the Northern Ireland Habitat Action Plans for Maritime Cliff and Slopes.

Proposed objectives/actions

  • Clarify the taxonomy, range and abundance of Scottish scurvy-grass

  • If confirmed as a species endemic to Great Britain and Ireland, populations should be monitored

  • Its importance as a distinct variant of common scurvy-grass should otherwise be recognised in the protection and management of the sites on which it occurs

  • Maintain the plant's current range.

What you can do
Records of this plant are needed to aid an assessment of its range and abundance. Report any records to The Botanical Society of the British Isles c/o Department of Botany, 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 5251 or Email: cedar.info [at] magni.org.uk.

Further information

Links
Flora of Northern Ireland

UK Biodiversity Action Plan

Northern Ireland Habitat Action Plans

Literature
Hackney, P. ( 1992). Stewart & Corry's Flora of the North-east of Ireland. 3rd Edition. Institute of Irish Studies, Belfast.

Rich, T.C.G. (1991). Crucifers of Great Britain and Ireland. BSBI Handbook No. 6. Botanical Society of the British Isles, London.

Text written by:
Paul Hackney