It is a country where there is not enough water to drown a man, wood enough to hang one, nor earth enough to bury him...
The words of the Cromwellian general Edmund Ludlow, describing the area known as the Burren, are well known in Ireland. What is less well known is that he went on to say of the people there:
... and yet their cattle are very fat; for the grass growing in turfs of earth, of two or three foot square, that lie between the rocks, which are of limestone, is very sweet and nourishing.
This combination of bare-looking rock and flourishing plant growth is what has produced the unusual and interesting flora of the Burren1.
Where and What is the Burren?
The Burren is an area of County Clare, on the Atlantic coast of Ireland. The Barony of Burren was an old land division including the northwestern corner of the county, named from the Irish word boireann meaning 'barren, stony place'. The modern National Park covers a region of roughly 375 square miles, bordered by Galway Bay on the north, and the Atlantic on the west.
The northern and western sections of the Burren form a bare, hilly limestone plateau, while the southeast is a lower-lying limestone area with some woods and lakes. In the main area, the limestone pavement is divided into slabs called clints, divided by crevices known as grikes, which may be up to two metres deep. Rainwater quickly runs underground into cave river systems. In the eastern sections, there are many of the seasonal lakes known as turloughs, which are typically full of fresh water in winter, emptying in spring to give good plant growth in summer.
The Burren has a very temperate climate. The average air temperature ranges from 15°C in July to 6°C in January, while the soil temperature drops below 6°C for only a few weeks in winter. Since grass will grow once the temperature rises above 6°C, this means that the Burren has one of the longest growing seasons in Ireland or Britain. The yearly rainfall ranges from around 100cm on the coast to 140cm further inland (39 to 55 inches). The third notable climatic feature is the wind. A fairly steady westerly or southwesterly wind blows in over the Atlantic, strengthening to produce regular gales in winter. This constant wind has a stunting effect on many trees and shrubs.
This large limestone area can be considered as a mosaic of habitats.
Grikes - While the actual pavement may be bare, the grikes or crevices provide moist shelter and support a wide range of plants including dwarf shrubs.
Loose gravel - Where the surface of the pavement is shattered into gravel, many of the hardier Arctic or Alpine plants can be found.
Grassy meadows - Where the pavement is covered by a thin layer of soil, patches of grass will be found, interspersed with plants like the gentian and orchids.
Heathland - A confusing feature of some areas is the development of thin patches of peat, which support lime-hating plants like heathers.
Woodland and scrub - There are occasional areas of woodland in more sheltered areas, with ash, holly, hazel and yew trees. More typical is dense hazel scrub.
Turloughs - These areas of land which are underwater for roughly six months in the year support a number of unusual species.
The flora is a very unusual mixture; some species are Arctic plants which are here at the southern end of their range, others are Alpine plants which in the Burren can occur down to sea level. Other species are more usually found near the Mediterranean, and are here at the northern end of their range. A further group, while often locally common in the rest of the country, are especially abundant here, so that the massed effect of wild flowers is striking and unique.
Arctic and Alpine Flowers
Perhaps the most famous of all the Burren flowers is the spring gentian Gentiana verna2. This flower is usually associated with the high meadows of the Alps. It is instantly recognisable due to its deep blue five-petalled flowers, usually about 2cm across. It is normally in full bloom in mid-May.
The classic Arctic flower of the Burren is the mountain avens Dryas octopetala. This has a creamy-white flower, usually 3 or 4cm across. It looks almost like a rose, but has eight petals. Occasional flowers can be found from April to September, but to see full carpets in bloom the best time is the end of May.
The Spring sandwort, Minuartia verna is another Alpine plant, much less conspicuous than the gentian, with small white flowers (just 1cm across) in May and June. The hoary rockrose Helianthemum canum is also a mountain plant, though its range stretches closer to the Mediterranean than most of the other Alpines species listed here. It has yellow flowers, only 1cm across, which only open in the sun. It flowers in late May.
Southern or Mediterranean Plants
The most famous Burren plant normally found in warmer climates is not a flowering plant at all, but the maidenhair fern Adiantum capillus-veneris. A favourite with the Victorians, this plant at one time suffered from over-collection, and its distribution is now rather scattered. Even when present, it can be hard to find, since it grows deep in the grikes where the air is kept moist.
The classic Burren Mediterranean species is the dense-flowered orchid, dealt with below.
There are at least 15 orchid species which can be seen in the Burren. The dense-flowered orchid Neotinea maculata is a Mediterranean species, whose greenish-cream flowers can usually be found at the same time as the gentian. The bee orchid Ophrys apifera and fly orchid Ophrys insectifera both mimic the appearance of insects, though while the fly orchid is pollinated by the excited wasps it attracts, the bee orchid in Ireland is actually self-pollinated. The fly orchid can be seen in June, and the bee orchid later in June and into July. A Burren speciality is O'Kelly's spotted-orchid, a white variety of the common mauve spotted-orchid Dactylorhiza fuchsii which was first spotted by a local farmer called O'Kelly. Both forms flower in July. Another orchid rare in other parts of Ireland is the dark-red helleborine Epipactis atrorubens, found both in grikes and on the more exposed gravel-strewn pavements. It flowers in July and August. An orchid found particularly around turloughs is the flecked marsh-orchid Dactylorhiza cruenta which flowers in June.
Plants of the Turloughs
The most striking plant of turloughs is the shrubby cinquefoil Potentilla fruticosa, which is rare elsewhere in Ireland and in Britain. It forms a shrub up to 1m tall, with yellow flowers that are usually 2 to 3cm across. The plant is often underwater in winter. The fen violet Viola persicifolia grows near the low water mark of turloughs. While a rare and unusual plant it is actually very easy to confuse with the common dog violet Viola riviniana. A peculiarly spindly form of the blackthorn or sloe Prunus spinosa can be found occasionally. The marsh dandelion Taraxacum palustre, whose yellow dandelion flowers grow on horizontal red stems, is another not very spectacular plant which is of great botanical interest, since it is more locally abundant around turloughs than in any of its other European habitats.
Woodland Plants and Shrubs
Plants which are normally typical of shady woodland areas, such as wood sorrel Oxalis acetosella, wood anemone Anemone nemorosa and honeysuckle Lonicera periclymenum, can be found flourishing in grikes, since the conditions there are suitably sheltered. Juniper (Juniperis communis) is found forming low creeping mats rather than upright shrubs, and some ash (Fraxinus excelsior), holly (Ilex aquifolium), and hazel (Corylus avellana) trees can be found in grikes, grazed down almost to the level of the pavement by goats and hares.
Other Interesting Plants
One of the most spectacular wild flowers of the Burren is the bloody cranesbill Geranium sanguineum. While it also occurs in other parts of Ireland, on the Burren limestone pavements and meadow areas it forms huge brightly-coloured masses in June and July. The flowers are 4cm across, and of a strong magenta colour which rarely shows up accurately in photos.
A common shrub on limestone pavements is the burnet rose Rosa pimpinellifolia. This rarely reaches a height of more than 0.5m and is a remarkably spiny plant with white, cream or pink flowers. Other fairly common plants that all contribute to the overall effect of the Burren flora are the hare bell Campanula rotundifolia, oxeye daisies Leucanthemum vulgaris, marjoram Origanum vulgare, wild thyme Thymus praecox, hemp agrimony Eupatorium cannabinum, primrose Primula vulgaris and cowslip Primula veris.
Viewing the Burren Flora
Late May is probably the best time to view the flowers of the Burren; the spring gentians are just past their peak, while the mountain avens are nearing their best. Orchid enthusiasts will prefer midsummer, when a number of orchid species are in full bloom, along with the bloody cranesbill.
Visitors should be aware that these species are protected by law, and any interference with the plants is forbidden. The limestone pavement can be quite treacherous to walk on, especially in those areas covered in loose gravel. The Burren Code gives some useful advice to visitors on how to respect the countryside.
An interpretative centre has recently been opened for the Burren National Park in the nearby town of Kilfenora. This can make a useful place to begin a visit, but there are many good maps and guidebooks available, which provide detailed information about the most interesting locations. Two useful tourism websites are that of Shannon Region Tourism and that of GoIreland; both these websites can be used to find suitable accommodation in the area. The small town of Ballyvaughan on the coast of Galway Bay is a particularly good centre for visiting the Burren.