Ben Bulben & The Dartry Mountains

Introduction

Browsing through my archive I rediscovered a variety of photos taken during 2009, my first year working in Ireland. That year I was based in Carrick-on-Shannon, Co. Leitrim. Our survey work ranged across the counties of Leitrim and Longford.

Much of that summer was spent surveying the endless rushy drumlins that make up the greater part of Co. Leitrim. While drumlins are pleasant enough the majority of the summer's botanical excitement was provided elsewhere. Namely in the small portion of the Dartry Mountains situated at the North West of Leitrim and in the the Northernmost edge of the Shannon Callows in Longford. For the purposes of this post I shall limit myself to the flora of the Dartry Mountains.

The Dartry range straddles the Leitrim / Sligo border with its most famous peak, Ben Bulben, lying at the south-west of the range near Sligo town. It reaches, at its highest, an altitude slightly greater than 500m. Despite their limited height these peaks have a impressive appearance the like of which I have not seen elsewhere. Neat, steep flanks of carboniferous limestone rise from the flat surrounds of the coastal plain and rapidly level off to broad summit plateaus. A series of deep glacial valleys dissect the range, hemmed by steep cliffs, crevasses and blocky boulder screes. These varied terrains are home to many interesting plants.

King's Mountain, Co. Sligo

Botanical History

The region supports a diverse and well studied flora. Its exploration began in 1700 when Edward  Lhuyd, mentioned previously in my post on Connemara, visited the area. He recorded a range of species including some of the local specialities such as the fern Polystichum lonchitis, known to him by the pre-binomial mouthful: Lonchitis Aspersa Matthioli  Sive Aspersa Major (1).

Edward  Lhuyd
Statue in AberystwythImage from www.vanderkrogt.net

Following this initial visit I can find little information of further botanical excursions to the area for over 180 years. Then, in 1883, two botanists meet their ends in atypically dramatic fashion for such a generally sedate pastime as botany. Thomas Hughes Corry and a friend were in the region carrying out fieldwork on the second year of a project to catalogue the flora of the Ben Bulben when disaster struck...

The accident is relayed with some panache in the preface to the 1888 work 'A Flora of The North-East of Ireland' co-authored by the late Mr Corry and his friend S. A. Stewart (2). Stewart describes the two botanists and their fateful decision to explore Lough Gill, a lake just to the south of King’s Mountain.

The morning of the trip dawns but is ‘not at all inviting. Heavy showers of rain [are] frequent, and [are] accompanied by [...] sudden and fierce squalls of wind.’ However the botanists ‘made light of the idea of incurring danger’ and ‘undeterred by the warnings of the boatmen […] put off in a light skiff, no doubt rejoicing in the thought that they could penetrate wherever it seemed desirable’. Their bravado is, however, ill-founded and when they do not return ‘[a] search, that night instituted, discovered the empty boat, and subsequently the bodies of the two unfortunate botanists’. As ‘no eye saw the occurrence, […] the exact details of the calamity will never be known’.

Despite their demise some of Corry's  notes on the region's flora were posthumously published in the Proceedings of the Royal Irish Academy, Science entitled 'On the Heights Attained by Plants on Ben Bulben' (3). This was quickly followed by a 1885 paper in the same journal by Richard M. Barrington and R. P. Vowell (a collaborator of Corry's during the initial survey)  entitled 'Report on the Flora of Ben Bulben and the Adjoining Mountain Range in Sligo and Leitrim' (4). This paper listed most of the species currently known from the range and included an addition to the Irish flora: Epilobium alsinifolium. This species can still be seen growing in a small flush near the wonderfully named Cloontyprughlish. A specimen from this (still the only known Irish population) collected by the great Irish botanist Lloyd Praeger can be viewed on Herbaria United web site.     

Personal Observations

The region supports a number of alpine species found nowhere else in Ireland including the previously mentioned Epilobium alsinifolium, as well as Saxifraga nivalis and one species found nowhere else in the British Isles: Arenaria ciliata.

Though currently restricted to these mountains A. ciliata once occurred more widely in the British Isles. A paper detailing preserved plant remains from a  Late  Devensian spring in Kent lists this species as present on the basis of a number of seeds. This shows that it did occur in the UK even if only about 10,000 years ago (5).

I did encounter this plant while on vascular diversion from a  bryological trip to the region a few years ago but, not having a camera at the time, was unable to take any pictures. However the Herbaria United page has a number of scanned images of material collected in the nineteenth and early twentieth century’s from Ben Bulben. Below is an image of an 1849 collection that seems to represent the earliest specimen on the site. It was collected by the prolific Somerset botanist Thomas Clarke.  

Arenaria ciliata specimen from Ben Bulben,
coll. Thomas Clarke, 1849
Image from Herbaria@home  

Many other, less rare, upland calcicoles are present. Some of these are particularly exciting for a Welsh botanist such as myself.  One of the most frequent of these is Saxifraga aizoides, the Yellow Mountain Saxifrage. Another species that is less common but still far more frequent here than in North Wales is Dryas octopetala. This species occurs in only two locations in Snowdonia with each of these populations amounting to but a couple of plants. Since 2009 the abundance of this plant I have encountered on the Galway limestone as well as in the Alps has somewhat dulled my excitement for it.

Saxifraga aizoides Glenade, Co. Leitrim, 2009

Dryas octopetalaGlenade, Co. Leitrim, 2009

Another species that is quite frequent here is the Irish speciality Euphrasia salisburgensis. The first unequivocal report of this species from Ireland is that of Nathaniel Colgan in 1897 (6). His paper details the confused history of the plant in Ireland dating back to a collection made in 1852 on Aran More. It is now known to be widespread on calcareous soils in the west of Ireland and is thought to be a obligate hemi-parasite of Thymus polytrichus (7). I have observed it in many places but it has a particularly fondness for the loose soil atop ant-hills.   

Euphrasia salisburgensis Glenade, Co. Leitrim, 2009

Finally a species that is very rare in Ireland, Arabis petra. This species is only known from Glenade (where the picture below was taken) and from the Galtee Mountains in Tipperary (8).   

Arabis petra Glenade, Co. Leitrim, 2009

------------------------------------

1. Mitchell, M. E. "Irish botany in the seventeenth century." Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science. Royal Irish Academy, 1975.
2. Stewart, S. A., and T. H. Corry. "A Flora of the north-east of Ireland." Belfast Naturalist's Field Club, Belfast (1888).
3. Corry, Thomas Hughes. "On the heights attained by plants on Ben Bulben." Proceedings of the Royal Irish Academy. Science 4 (1884): 73-77.
4. Barrington, Richard M., and Richard P. Vowell. "Report on the Flora of Ben Bulben and the Adjoining Mountain Range in Sligo and Leitrim." Proceedings of the Royal Irish Academy. Science 4 (1884): 493-517.
5. Kerney, Michael P., R. C. Preece, and C. Turner. "Molluscan and plant biostratigraphy of some Late Devensian and Flandrian deposits in Kent." Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences (1980): 1-43.
6. Colgan, Nathaniel. "Euphrasia Salisburgensis, Funk., in Ireland." The Irish Naturalist 6.4 (1897): 105-108.
7. Webb, David Allardice, and Mary JP Scannell. Flora of Connemara and the Burren. Cambridge University Press, 1983.
8. Stelfox, A. W. "The forms of Cardaminopsis petraea (L.) in Ireland." The Irish Naturalists' Journal 16.10 (1970): 308-309.