Northern Ireland's Priority Species

Carex elongata – elongated sedge

 

Distribution map

Click here to view an interactive map of the Northern Ireland dataset as currently collated by CEDaR.
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Carex elongata L.
Family: Cyperaceae

A scarce plant of wet woodlands that was first discovered in Ireland beside Lough Neagh in the early nineteenth century, but was presumed extinct there for nearly a century. It is now known to be sparsely scattered around most of Lough Neagh (apart from the County Down shore), and also to be present in south Fermanagh.

In brief

  • A sedge of seasonally flooded woodlands
  • Known from lakeside woodlands around Lough Neagh and south Upper Lough Erne, but nowhere in abundance
  • A distinctive species flowering early in the summer
  • It is a scarce species with Northern Ireland being a stronghold of the Irish population
  • Any action which may compromise the wet woodland habitat will adversely impact upon this species.

Species description
With only short underground rhizomes, this species forms dense tufts of slender upright bright yellow-green, grass-like leaves usually with persistent light brown dead leaves at the base. The flower heads, borne on rough, three-angled stems are typically around 50cm, and up to 90cm tall but do not extend much beyond the leaves. Each flower head comprises oval bundles formed of many flowers which have pale red-brown scales with the midrib contributing a green stripe. The English name of this plant refers to the elongated nature of these flower bundles up to 1.8cm long, they are discretely spaced along the stem forming a flower head of 3-7cm. Although narrow and upright at first, characteristically the mature flower bundles lean away from the stem to angles approaching 90°. The fruits when they are formed are a narrow flask-shape and ribbed.

Life cycle
The tussocks persist year round, but in the winter appear largely dead. New green shoots appear early in the growing season and the flowers are produced in May. These are wind pollinated, and viable seed is readily produced, although some English populations are reported to have a poor seed set. By the time the fruits mature, the leaf tips have already started to brown.

Similar species
Although sedges can present difficulties in identification, this one is reasonably distinct. When mature flowers are present the brown flower bundles leaning outwards from the stem are indicative. The most common superficially similar species which may occupy similar habitats in Northern Ireland is brown sedge (Carex disticha) which has more bulky flower bundles oriented upwards to form a much denser flower head. Less common species of different habitats, spiked sedge (Carex spicata) and prickly sedge (Carex muricata ssp. lamprocarpa) have smaller, less elongate flower bundles comprising fewer flowers. The very oblique junction where the leaves sheath around the stem, and the accumulation of dead leaves and sheaths at the base of the tussock, are further confirmation if required.

How to see this species
This is a plant of alder and willow woodlands that are subject to winter flooding but which dry in summer, such as those found at lake edges. In the wetter areas it will perch above the summer flood level on fallen decayed timber. The easiest place to see this species is on the Crom estate, owned by the National Trust and always an interesting place to visit. Look either on the main shore or beside Derrymacrow Lough. It flowers early in the summer.

Current status
When records were compiled for the BSBI Atlas2000 Project, this species was refound at most of its known locations around Lough Neagh and Crom.

The first record of this species in Ireland was made by Dr David Moore in 1838 in a woodland near Gawley’s Gate — subsequent searches by Samual Stewart less than 50 years later found the woodland destroyed so the plant was then believed lost from the area but was subsequently rediscovered at six different places around Lough Neagh between 1971 and 1973 by John Harron, though nowhere in abundance. In the mean time it was confirmed around Crom in South Fermanagh by Desmond Meikle in 1947 and is now known from several woodlands adjacent to the main Upper Lough Erne shore and in satellite lakes.

Why is this species a priority in Northern Ireland?

  • It is a scarce species with Northern Ireland being a stronghold of the Irish population.

Threats/Causes of decline
Any action which may compromise the wet woodland habitat will adversely impact upon this species — this includes not only clearance and infilling, but also drainage, summer overgrazing, and increasing nutrient status favouring other species — elongated sedge does not prosper amongst other tall vegetation. Elsewhere, wash from boats, and bank stabilisation has caused the loss of canal side colonies.

Conservation of this species

Current action

  • All but one known sites for this species fall within designated Areas of Special Scientific Interest, with Upper Lough Erne, and Reas Wood/Farr’s Bay additionally designated a Special Area of Conservation, and Lough Neagh a Special Protection Area.

Proposed objectives/actions

  • The status of elongated sedge will be surveyed and monitored and appropriate conservation action undertaken if required.

What you can do
Keep an eye out for this distinctive sedge in suitable habitats, although be aware that wet woodlands at lake edges are dangerous places. Should the species be seen or suspected, provide notes, including the exact location and an estimate of the population size to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU. Tel. 028 9039 5256, email cedar.info [at] magni.org.uk.

Further information

Links
Flora of Northern Ireland

NI Habitat Action Plan for Wet Woodland

Craigavon Local Biodiversity Action Plan Wet Woodland

Designated Sites

Literature
Meikle, R.D. and Moon, J.McK. (1947). Carex elongata in County Fermanagh. Irish Naturalists’ Journal 9: 30.

Harron, J. (1974). Carex elongata refound on Lough Neagh Shores. Irish Naturalists’ Journal 18 (3): 91-92.

Text written by:
Shaun Wolfe-Murphy