Northern Ireland's Priority Species

Cryptogramma crispa – parsley fern

 

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.

 

Cryptogramma crispa (L.) R.Br. ex Hook.
Family: Adiantaceae

Parsley fern is a very rare species in Ireland, with the main centre of occurrence in the north and east. The Irish plants are generally small and stunted; they grow in small tufts in crevices in non-calcareous rock at high altitudes.

In brief

  • Found in hilly districts of Counties Down, Antrim and Londonderry

  • It grows in crevices of acid rocks

  • It can be found at all times of the year

  • A priority species because Northern Ireland most of the recently recorded Irish sites lie inside Northern Ireland and it is apparently declining.

Species description
The English name is a reflection of the general appearance of the plants, which have leaves much divided into small segments somewhat like parsley. Leaves are of two sorts, sterile and fertile. Fertile leaves are longer than sterile leaves with the edges of the segments turned over and almost hiding the sori where the spores are produced.

Irish plants are generally very small and poorly developed compared with plants in Great Britain.

Life cycle
The spores ripen and are shed between June and August and they germinate to produce the sexual stage of the species. Parsley fern has a typical fern life cycle involving the alternation of the asexual spore-producing plants (sporophytes) with a sexual stage which is tiny and is rarely seen – in fact there appear to be no records of any sightings of the sexual stage from Ireland. The sexual stage produces a fertilised egg which forms the embryo of the sporophyte. The habitat preferences of the plant will be partly determined by the habitat requirements of the sexual phase – in particular shelter from dessication and the presence of some free moisture for the crucial stage of fertilisation.

Similar species
There are no similar species which could be mistaken for this plant.

How to see this species
This is a very difficult plant to find in Northern Ireland, partly because of its rarity and partly because of its generally small size. Before searching for parsley fern in Ireland, it is probably advisable to familiarise yourself with the well-grown plants found in Great Britain where it is locally abundant, for example, in the English Lake District or in the old slate quarries in Snowdonia in Wales. In contrast to the luxuriant growths of parsley fern in these districts, in Ireland the plant is usually stunted and poorly-developed, making it difficult to see. It also grows in small numbers, often as isolated plants. Some of the best-known sites are on the Trosks above Carnlough in County Antrim and on and near Pigeon Rock in the Mourne Mountains in County Down.

Current status
Since 1980, this plant has been seen at sites in the Mourne Mountains of County Down, the Garron Plateau area above Carnlough in County Antrim and Benbradagh and Mullaghmore in County Londonderry. The total number of sites from Counties Down and Antrim total about 26. At about two-thirds of these it has not been seen since 1980 and of these there are about 11 sites where it has not been seen since the 1800s. There is a single report from Slieve Gullion in County Armagh, dated 1965 and an old report from Cuilcagh in County Fermanagh from 1866. In County Londonderry the plant has been seen a number of times in the 1980s and 1990s around Mullaghmore and Benbradagh. Based on the historical and recent records, it appears that parsley fern has declined by about 50 per cent since 1900, but the difficulty of finding this species may mean that the decline is more apparent than real.

Parsley fern is not subject to any specific legal protection in Northern Ireland at present.

Why is this species a priority in Northern Ireland?

  • More than 50% of the Irish population occurs in Northern Ireland and apparently declining.

Threats/Causes of decline
Although apparently declining, this may be a function of under-recording. It is difficult to see what might threaten parsley fern in its Irish sites, which are usually remote and at fairly high altitudes well beyond areas subject to damage by urbanisation or agricultural change. Grazing by sheep may affect some sites and limit the ability of the plant to expand, but this seems an unlikely explanation bearing in mind the difficulty of access of some of the sites even for sheep.

The poor quality of the Irish plants suggests that this species is at the edge of its natural range in Ireland at present and perhaps climatic changes have adversely affected it, but the factors involved are unclear.

Conservation of this species

Current action

  • The Garron Plateau and Mournes sites lie within Special Areas of Conservation and ASSIs

  • Other sites lie within areas designated as ASSIs, for example, Slieve Gullion ASSI

  • Sites are monitored on an ad hoc basis by botanists.

Proposed objectives/actions

  • Maintain the number of viable populations of this species

  • Maintain the range of the species

  • Establish appropriate management on appropriate historic sites

  • If refound, ensure that the population is maintained.

What you can do
Keep an eye out for parsley fern in suitable sites, especially in the old areas where it formerly appeared. The plant may still occur at some of these. If found report to the Botanical Society of the British Isles, 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
Flora of Northern Ireland

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

Text written by:
Paul Hackney