Northern Ireland's Priority Species

Calamagrostis stricta – narrow small-reed

 

Distribution map

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Calamagrostis stricta (Timm) Koeler
Family: Poaceae

Narrow small-reed (Calamagrostis stricta) is a grass species that has never been recorded in the island of Ireland apart from on the shores of Lough Neagh and Lough Beg. It is thought to have disappeared from most of its former sites around these important lakes due primarily to drainage, and is now very much a threatened species here.

In brief

  • A plant of wet meadows
  • Formerly found around much of Lough Neagh and Lough Beg, but extinct from many of its former sites
  • Flowers through the summer
  • Threatened as an Irish species and is restricted to Northern Ireland within Ireland
  • The main cause for its decline has been drainage, but it is also sensitive to site management
  • The Irish population is recognised as a distinct variety

Species description
This is a patch-forming, reed-like, perennial grass with erect stems from 30 to 100cm tall and with narrow leaves after which it is named. It has much branched and bushy, but narrow flower heads of spikelets which, like the bent grasses (Agrostis spp.), have only one flower per spikelet. The outer flower scales (glumes) are closed early in the year, but are persistent and gape later in the summer after maturation.

It has elongated slender rhizomes, but where the plants arise it forms tufted tussocks. Leaf sheaths are smooth. The leaves vary in width from 1.5 to 5mm and may be slightly rolled. They are sparsely downy above, smooth below and rough to the touch along the edges.

This is a variable species, but our Irish plants are distinct enough to have been recognised as a variety (var. hookeri), presumably the result of long genetic isolation.

Life cycle
Little detail is known of the life cycle or ecology of this species. It is a perennial species – plants persist for several years. Leaf and stem growth occurs in early May to mid-June followed by significant growth of shoots. Plants flower from June to August, after which the aerial parts begin to die back. Presumably seeds require suitably damp and open conditions to germinate, but this grass can also spread vegetatively through the extension of rhizomes.

Similar species
Calamagrostis is a large genus of plants with about 230 species which occur in the temperate zone across the Northern Hemisphere. Whilst narrow small-reed can be confused with purple small-reed (Calamagrostis canescens) in mainland Britain, this is unlikely to be a problem here. Five native species occur in Great Britain, but only two of these occur in Ireland, wood small-reed (Calamagrostis epigejos) and narrow small-reed (Calamagrostis stricta) – both species of conservation concern in Northern Ireland (wood small-reed has wider and hairless leaves). Some erect forms of creeping bent (Agrostis stolonifera) may resemble narrow small-reed at certain times of the year, but in narrow small-reed the inner flower scales known as lemmas have conspicuous tufts of white hairs arising from the base of the outer face of the scale.

How to see this species
This is a species of wet meadows close to lake shores. The only confirmed contemporary site for this species in Northern Ireland is in the extensive wet meadowland along the western shore of Lough Beg. This is within Lough Beg NNR but the land is privately owned. Access to Lough Beg NNR to see the plant is best arranged through EHS, Tel: 028 3885 3950.

There are former twentieth-century records from various localities along the Londonderry and Antrim shorelines, especially between Toome and Antrim, such as Masserene Park and Shane’s Castle Park. The plant may possibly be hanging on in some of these sites. There are much older records from Washing Bay, Scawdy Island and the mouth of the Lagan Canal, but the plant has long been considered extinct from the southern side of Lough Neagh.

Like most grasses it is less likely to be noticeable and harder to identify when it is not in flower. It is best looked for in ungrazed or lightly grazed vegetation between June and August. Relevant access permissions should always be sought prior to visiting any sites.

Current status
The first Irish record for this species was on a small island in Lough Neagh by David Moore in 1836 whilst working as a botanist attached to the Ordnance Survey. He sent a specimen to William Jackson Hooker who identified it incorrectly at first as Lapland reedgrass (Calamagrostis lapponica) (a painting of this original specimen by George Victor Du Noyer can be found at the Botanic Gardens, Glasnevin, Dublin). By 1852, however, Hooker had revised his opinion and re-identified the plant as narrow small-reed.

By 1864, George Dickie in his Flora of Ulster correctly predicted the extinction of this species in several sites due to drainage works. The present water level in the lake is around 1m lower than it was prior to the start of several successive schemes, starting with the McMahon scheme in 1847. David Moore’s work was mainly on the Antrim and Londonderry shores and this was where he subsequently found several other sites for this grass; it was only decades later that the plant was found elsewhere on Lough Neagh, by which time it is possible that some colonies had already disappeared.

It was not refound on the Lough Neagh shore during the BSBI’s Atlas 2000 surveys. The population on Lough Neagh also is known to have declined significantly, and the entire Irish population of this species is therefore distinctly threatened.

All wild plants are given some measure of protection in Northern Ireland under the Wildlife (NI) Order, 1985, but narrow small-reed is amongst the fifty-six species, listed in Schedule 8, which are given special protection. The order has the effect that you may not: intentionally pick, uproot or destroy, or even collect the flowers or seeds unless specifically licensed by the Environment and Heritage Service.

Why is this species a priority in Northern Ireland?

  • Decline (1 per cent per year) and rare – population restricted to Northern Ireland within Ireland
  • Listed in the Irish Red Data Book as ‘Vulnerable’.

Threats/Causes of decline
Drainage is obviously the main threat to this species and indeed its habitat. Even if the wet meadows where it grows are maintained, the species remains vulnerable to other factors such as over-grazing (it is a grass palatable to livestock) and nutrient-enrichment.

Conservation of this species

Current action

  • The entire known contemporary population is included within the designated site of Lough Beg ASSI and NNR
  • The Lough Neagh Advisory Committee has produced a management strategy for Lough Neagh and Lough Beg
  • Implementation of the Northern Ireland Habitat Action Plan for Floodplain Grazing Marsh.

Proposed objectives/actions

  • Maintain the number of known viable populations of the species
  • If refound ensure that the population is maintained.

What you can do
Records of this species are important. There are opportunities to search for this species in any wet/damp meadow area close to Lough Neagh’s shore. This should be undertaken over the summer when the species is in flower. If plants resembling this species are found, identification must rely upon examining the flowers on the plant to check that there is a small beard of hairs within the solitary flower in the spikelet. This being the case, make careful notes on the site and the plants location within it, and send any records (including photograph if possible) to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU, Tel: 028 9039 5256 or email: CEDaR.info [at] magni.org.uk.

Further information

Links
Lough Beg ASSI

Flora of Northern Ireland

Northern Ireland Habitat Action Plans

Lough Neagh and Lough Beg Management Strategy

Literature
Crackles, F.E. (1997). Variation in some populations of Calamagrostis stricta (Timm) Koeler in the British Isles and the putative past hybridization with C. canescens (Wigg.) Roth. Watsonia 21(4): 341-354.

Harron, J. (1986). The Flora of Lough Neagh. The University of Ulster, Belfast.

Text written by:
Shaun Wolfe-Murphy