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Fly Orchid (Ophrys insectifera)

Narrow-bordered Bee Hawk Moth

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Poulnabrone Portal Tomb

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June 1st-6th - The Burren, County Clare.


More than 700 species of flowering plants, conifers and ferns occur in the Burren. The limestone pavements are the outstanding feature but there are also areas of acid soils, woodland, hazel scrub and the turloughs (lakes that disappear for part of the year, leaving a pasture with grasses, sedges and herbs), these plants have to be able to survive under water for half the year.  The first plants to arrive after the end of the Ice Ages were from the Arctic tundra and Mountain Avens still grows at sea level alongside Alpine Spring Gentians, the Mediterranean Dense-flowered Orchid and the tropical Maidenhair Fern.

On Saturday 2nd June, a geological stop gave us a first view of limestone plants – Bloody Cranesbill (Geranium sanguineum), Burnet Rose (Rosa spinosissima), and Mountain Avens (Dryas octopetala). Common Spotted Orchids (Dactylorhiza fuchsii) were examined in case the white specimens were the O’Kelly sub-species (ssp.okellyi) which normally flowers later in the summer and is named after the Burren farmer who first collected it in the 1890s. We picnicked by the marl-encrusted shores of Lough Bunny in an acid-area among Butterwort (Pinguicula vulgaris), the Burren speciality Shrubby Cinquefoil (Potentilla fruticosa) and Stone Bramble (Rubus saxatilis) which has red fruits later in the summer. Purple Early Marsh Orchids were Dactylorhiza incarnata var.pulchella with limestone and marl lake-shore varieties var.hyphaematodes and var.haematodes. The rain was coming on, so no one was enthusiastic enough to get down on their knees to examine the spots on the leaves to confirm the identifications.  The convoy of cars managed to keep together up and down narrow twisty roads with grass growing up the middle to arrive at the welcoming tea room of the Burren Perfumery, where we visited their herb garden.

On Sunday, after an low-tide transfer from Doolin onto small boats and then to the ferry heaving in the bay, we spent the day on Inisheer.  Bee Orchids (Ophrys apifera) were growing in profusion near the beach – Irish and British Bee Orchids are self-polllinating so do not need their elaborate shape to attract pollinators. The dust-like seeds can be carried for miles in the wind but take up to 8 years to reach the flowering stage. Sea Spurge (Euphorbia paralias), Yellow-wort (Blackstonia perfoliata), a Centaury (Centaurium erythraea) with pairs of leaves joined at the base, and Cowslips (Primula vulgaris)were growing nearby.  Babington’s Leek (Allium babingtonii) is common on the Aran Islands – the bulbils grow in clusters with the flowers. In hollows in the limestone pavements were large cushions of Irish Saxifrage (Saxifraga rosacea) which also grow in the mountains of central Europe and Iceland.
Monday was a botany day and the sun shone. Brian, our bus driver, always managed to stop at the exact spots to find Burren specialities near Black Head - Spring Gentians (Gentiana verna) were in flower, in seed and still in bud, Wild Madder (Rubia peregrina) and Maidenhair Fern (Adiantum capillus-veneris) in the grikes or scailps, at Murrough - Bloody Cranesbill (Geranium sanguineum), Hoary Rockrose (Helianthemum oelandicum/canum) which is a Mediterranean mountain plant, and a profusion of orchids.  We picnicked at Fanore but never reached the beach as the grassy machair-type area had more gentians, Irish Eyebright (Euphrasia salisburgensis), a parasite on thyme which, as the name implies, also occurs in the Austrian mountains, lots of Pyramidal Orchids (Anacamptis pyramidalis) and the strange thread-like parasite Dodder (Cuscuta epithymum). At Poulsallagh, Hemp Agrimony (Eupatorium cannabinum) was emerging from the grikes – Eupator was a King of Pontus and cannabinum because of its resemblance to hemp.  Mountain Everlasting (Antennaria dioica) was growing on rocks along with another mountain plant Spring Sandwort (Minuartia verna), at sea-level.

Next day was archaeology, but Liam found over 12 Twayblades (Neottia Listeraovata) in a grike beside the Poulnabrone Portal Tomb.  Several of us went to the Slieve Carron Nature Reserve where there were at least 50 Fly Orchids (Ophrys insectifera) in flower. These strange plants produce a scent which mimics the sex pheromone of a wasp and are pollinated by newly-hatched male wasps of the genus Gorytes. Their pseudo-copulation puts them in exactly the right position for pollinia removal and deposition, but once the female wasp emerges , the males transfer their interest away from the flowers.

As always the Burren provided a wonderful combination of interests botanical, geological, zoological and archaeological.

Some thoughts on Irish Orchids.

Including hybrids there are about 37 varieties of Orchids in Ireland. Ongoing molecular investigations are moving some orchids into different groups and changing names. The Dactylorchids have always been the most difficult to differentiate, but there are 3 basic groups :-

1.Common Spotted and Heath Spotted - Dactylorhiza fuchsii & maculata

2.Early Marsh Orchids - Dactylorhiza incarnata with subspecies coccinea, pulchella, hyphaematodes/cruenta,incarnata

3.Broad-leaved, Northern, Irish, Western, Narrow-leaved  Marsh Orchids – Dactylorhiza majalis with subspecies occidentalis, kerryensis, purpurella/brevifolia,traunsteinerioides. This group is a hybrid probably of D. Fuchsii and D.incarnata and has double sets of chromosomes (tetraploid).

“New Journal of Botany” Vol 2 number 1, 2012 Bateman & Denholm has 18 pages on ”The Taxonomic reassessment of the British& Irish tetraploid marsh-orchids”. This appears to reduce the Irish group to D.kerryensis, purpurella and traunsteineriodes with some variants. The authors admit that “remarkably little consensus is evident among specialists regarding the classification of the tetraploid marsh-orchids”, so we amateurs can be excused for having difficulties in our attempts to identify the orchids we encounter.


Margaret Marshall

Thanks to Liam McCAughey, Abigail Dunnes and Samuel Millar for the use of their photographs.

 

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