Northern Ireland's Priority Species

Euphrasia anglica – glandular eyebright

 

Distribution map

Click here to view an interactive map of the Northern Ireland dataset as currently collated by CEDaR.
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Euphrasia anglica Pugsley
Family: Scrophulariaceae

The genus Euphrasia in Britain and Ireland consists (at the moment of writing) of 27 named microspecies of annual herbs with fibrous roots. The very wide variation in Euphrasia populations makes it difficult to decide what exactly is a species in this genus. Notoriously, most of the forms that are named and described as microspecies do not behave as 'good species'. Rather, they vary widely in response to their local environment and they cross with neighbouring microspecies. Both diploid and tetraploid forms occur crossing to produce triploids offspring. Unusually, even the triploid Euphrasia crosses are not totally sterile: they can form euploid gametes that contribute to gene flow through introgression with diploids and tetraploids (Stace 1993; Sell & Murrell 2009). Hybrids are found growing with or without their parent species. Seasonal dimorphism may also occur: early summer and late autumn flowering plants differ from one another, some described as varieties or subspecies (Briggs & Walters 1997).
The Euphrasia complex is a collection of more or less selfing lines, with varying degrees of reproductive isolation. They require careful expert examination and comparison of multiple specimens to resolve and name the forms present. Certainty in this quest is illusory. Even the experts qualify their determinations with a query (Webb & Scannell 1983). Some currently named forms will probably eventually be recognised as mere ecotypes (Karlsson 1976).

In brief

  • Glandular Eyebright is very poorly known and there are very few definite records of it in Northern Ireland
  • Elsewhere in Ireland it is rare, local or occasional, mainly recorded in Connemara and the Burren Co.Clare, and in Cos. Cork, Wicklow and Dublin
  • Records are also very thinly scattered in Central Ireland
  • It is a species of grazed, damp grasslands on acidic soils of moors, heaths, roadsides and old quarries
  • Flowering occurs in mid- to late summer
  • Imperfectly recorded in many regions, but as far as we can tell, this species appears to be nationally rare and declining throughout most of the UK
  • There are a total of just seven records of Euphrasia anglica in Northern Ireland in the CEDaR database, only three of which have been critically determined by experts in the genus
  • It is almost certainly under-recorded here
  • In northern Britain and Ireland E. anglica appears to intergrade with E. rostkoviana.

Species description
A rather distinctive annual, the upper and middle leaves are covered with long gland-tipped hairs. The glandular hairs are easily visible to the naked eye, appearing like a greyish or whitish, somewhat crisped down spread over the upper leaves, bracts and flower petals. Grazed plants are dwarfed, but otherwise it is a straggling, ascending, irregularly branched plant, often not more than 20 cm long with a flexuous stem. The flowers are stalkless in the axils of bracts, in a loose terminal spike. The lowest flower is borne at node 5 to 8 on the stem (Sell & Murrell 2009). The species is most readily distinguished in SW England: elsewhere material is very difficult to name (Silverside 1991).

Life cycle
All species of Euphrasia in Britain and Ireland are hemi- or semi-parasitic annuals. Their roots are attached and partially dependent upon those of host plants of a different species. Seed germinates in spring and attaches to a suitable perennial host whenever root contact is made. No information is available on host plants, but as it occurs in a range of habitats it is unlikely to be host specific. It generally grows in permanent grassland communities. Flowering occurs from June to August and pollination is by small insects, e.g., hoverflies. Populations show marked fluctuations in abundance from year to year. Euphrasia species are not strongly competitive and grazing prevents accompanying vegetation becoming tall and rank (A.J. Silverside in: Wigginton, M.J. (ed) (1999)).

Similar species
The most similar species is E. rostkoviana which also possesses the long glandular hairs that characterises E. anglica. E. rostkoviana is a more upright plant with slightly larger flowers. In northern parts of these islands these species intergrade with one another. This phenomenon occurs when closely related forms approach the limits of their overlapping tolerances and distribution. In SE England E. anglica is easily distinguished from E. rostkoviana, but in Ireland this is not the case. Reseach on Irish Euphrasia material is urgently required.

How to see this species
There is nowhere in Northern Ireland where E. anglica can be readily seen. Recognition is difficult as significant plant parts are small and other Eyebrights are very similar. The best approach might be to visit the Burren and SE Connemara in summer, or better still visit SW England.

Habitat

Despite the reservations noted, the most frequent and widespread Euphrasia species tend to occur in characteristic habitats. Thus E. anglica is a mainly lowland plant of damp heaths and old, unimproved, moorland pastures over acidic substrates, especially when these are tightly grazed. It also occurs in disturbed artificial habitats, such as disused quarries, roadsides and field margins.

Current status
Listed as a Northern Ireland Priority Species of Conservation concern, E. anglica is extremely rare or possibly extinct in Northern Ireland. The last definite, expertly determined record of E. anglica in Northern Ireland was made in 1939. All the habitat types favoured by this species are widespread in Ireland, but the taxonomic uncertainty surrounding the genus creates difficulties in designing Biodiversity Action Plans for threatened and endangered microspecies. There are serious practical difficulties with identifying some of the local or endemic microspecies that have been given high priority conservation status both here and in Britain. Further genetic research on Euphrasia is needed.

Why is this species a priority in Northern Ireland?
This species is extremely rare in Northern Ireland. It appears to have declined by up to 62% in Britain, where it is now listed as a Red Data endangered species of high conservation priority.

Threats/Causes of decline
Essentially a pasture species, E. anglica is sensitive to both excessive grazing pressure which prevents it seeding, and abandonment of grassland management leading to the growth of taller, competing grasses and herbs. Nutrient enrichment or herbicide pollution could also oust the species.

Conservation of this species

Current action
Implementation of the Northern Ireland Habitat Action Plan for Grasslands, especially the Purple moor-grass and rush pastures.
For many priority species conservation action will be undertaken through UK species action plans, the management of designated sites, or as a part of Northern Ireland Habitat Action Plans.

Proposed objectives/actions

  • Increase recording effort to locate viable populations of the species by surveying suitable sites
  • If refound ensure the population is maintained

What you can do
Records of new sites and estimates or counts of the sizes of populations are always valuable. Send information (including photographs, if obtained) to The Botanical Society of the British Isles c/o of Botany Department or CEDaR, at National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU, Tel: 028 9039 5256, cedar.info@magni.org.uk.

Further information

Links
Glandular eyebright species page on UK BAP

Northern Ireland Habitat Action Plans

Photo of Glandular eyebright

Literature
Briggs, D. and Walters, S.M. (1997). Plant Variation and Evolution, 3rd edition, Cambridge University Press, Cambridge.
Karlsson, T. (1976). Euphrasia in Sweden: hybridization, parallelism and species concep. Bot. Notiser. 129: 49-60.
Sell, P. and Murrell, G. (2009). Flora of Great Britain and Ireland, Volume 3, Mimosaceae - Lentibulariaceae, Cambridge University Press, Cambridge.
Silverside, A.J. (1991). The identify of Euphrasia officinalis L. and its nomenclatural implications. Watsonia 18: 343-350.
Stace, C.A. (1993). The importance of rare events in polyploid evolution. In Evolutionary patterns and processes ed. D.R. Lees & D. Edwards, Linnean Society Symposium Series 14, pp. 157-69. London: Published for the Linnean Society by Academic Press.
Webb, D.A. and Scannell, MJ.P. (1983). Flora of Connemara and the Burren, Royal Dublin Society and Cambridge University Press, Cambridge.
Wigginton, M.J. (ed) (1999). British Red Data Books 1 Vascular Plants, 3rd edition, Joint Nature Conservation Committee, Peterborough.

Text written by:
Ralph Forbes