Bog Orchid Hammarbya paludosa found on North Uist

Lee Thickett

The Bog Orchid has a circumpolar distribution scattered through Eurasia and North America. In Europe it has been recorded from the Faeroe Islands and up to 69° N in Scandinavia to as far south as France, the Alps and Romania.

In Britain it has a presence in West Wales, the Lake District, the Scottish Borders, and scattered sites elsewhere, but is much more common in Dorset and Hampshire. In Scotland it is widespread, more especially in the north-west, where it can be locally common. In the Western Isles in the years since 1930, it has been recorded in scattered localities from Lewis south to Barra. From 2000 to date it has been recorded in just 6 10 km squares on Lewis, Harris, North Uist and Barra. This article is about the discovery of Bog Orchids in the North Uist 10 km square in July 2003, and subsequent visits to the sites.

Bog Orchid is our tiniest orchid being 2 – 15 cm high, but usually in the range of 4 – 8 cm, which compares with 5 – 10 cm for Lesser Twayblade Listera cordata. Indeed some of the plants we have found on North Uist have been shorter and more slender than a match-stick.

Over the years we have managed to find most British orchids, but Bog Orchid had eluded us. Looking at the distribution map on the BSBI web site we noticed the widespread scattering of records in North-West Scotland and the Western Isles and decided it would fun and realistic to look for it on Uist, which we had visited 11 times by 2003, and which had for us become a ‘home from home’. Our first attempts were centred around the walk past Rueval over to the East coast of Benbecula. We did not find any here, despite much peering into soggy bogs. The next day on the 11th July 2003 we set off from where we stayed in Sidinish and headed across the moor on the ‘Eaval Track’. We headed north from this track and hiked up and over the northern shoulder of the wee hill called Burabhal, and it was during the descent on the eastern side that we spotted our first Bog Orchid. This was all the more remarkable for the fact that at the time we were not diligently searching for Bog Orchids as we were descending a series of muddy steps with a patchwork of stones, heather, mud and moss ; a sheep- and deer-track in fact, and not a classic Bog Orchid habitat. Our goal that day was simply to reach the East coast of North Uist for the first time, so spotting the orchids was a stroke of the most wonderful good luck. We found 28 Bog Orchids in this unlikely looking site, in 2007 we found 10, and in 2011, just 1. This illustrates one of the fundamental mysteries of Bog Orchids. In one year you may find many, and at the same site in following years find none or very few.

On the way back to Sidinish, as we descended the west side of Burabhal’s northern shoulder, we encountered a mossy runnel that curved northwards towards Loch Eport. This looked more like the habitat mentioned in the orchid books; wet, lots of sphagnum moss and a decent slope so that the water is always moving. As we walked down alongside the runnel, bent double, searching for these elusive plants, suddenly here was one, and over there another. We counted 18 here, and a few days later, 17. Our tally on the 11th of July was 46 Bog Orchids in two sites. To say we were elated does not describe our feelings, we were overjoyed. At the same time we were a little rueful as we had stayed as Sidinish for two weeks in each of the previous two years and had roamed over the west slopes of Burabhal many times without noticing the diminutive treasures that were almost certainly there. Later in the same holiday we found another site near Loch Obisary and yet another near the famous Druim na h-Uamh. This latter site is interesting as it is the only site we have found so far that is not on the slopes of Burabhal.

In total, from 2003 to 2011 we have found 10 sites on Burabhal and counted the following flowering spikes:

2003	2004	2007	20010	2011
53	38	40	41	38

In the years missing from the list above we visited Uist either too late or too early for Bog Orchid, apart from 2008 which we concluded was too dry for them. Our conclusion may be mistaken as there are sites which we have since found that may have held Bog Orchids at the time.

But how do you spot the wee blighters when they are so small? One trick we have found useful when searching for a species whether a sea slug, dragonfly or orchid, is to have a target image firmly in mind when searching, but this image may not be the typical book illustration. For example when searching in leggy heather for Lesser Twayblade, it is not helpful to look for the side-view of the spike. The most prominent feature as you look down on these orchids through the heather are the two leaves at the base. We have found searching for the two leaves to be more efficient.

With Bog Orchid, they are usually so tiny, especially when viewed from some metres away, that often there is no impression of the shape of the spike. However the colour is distinctive. I could describe the colour as yellowish-green but take a look at the picture and study the colour. We let our eyes roam over the runnels looking for little smudges of this colour amongst all of the other vegetation. It works for us, and once you have seen a Bog Orchid, study and memorise the colour: it pays dividends. By the way close-focussing binoculars are wonderful aids for this, and we have located Bog Oorchids using these and spotting just a glimpse of the colour behind and amongst other plants.

One word of caution. Bog Orchids live in fragile habitats, are small and easy to overlook. If you spot one a metre or two away try to approach it on ‘dry land’ avoiding treading on the moss. Look closely where you a putting your feet as there may be Bog Orchids much closer than you think.

Here are a few curious facts about Bog Orchids that add to their fascination.

1. It is thought that they produce no food by photosynthesis , their leaves being so tiny they cannot harness the sun’s rays to do this, and they have no real root, only tiny hairs. Instead they rely on the mycorrhizal fungi with which they are infected and which can harvest food for them both to use.
2. Like Fen Orchid, they are epiphytic, that is, they usually grow on another plant’s structure (sphagnum moss) but do not parasitise nutrients from it.
3. The individual flowers on an orchid rotate so that the lip (‘labellum’) moves from pointing upwards, to pointing down to the ground. In Bog Orchid, the flower continues rotating through 360 ° until the lip is once more pointing upwards.

Are there more Bog Orchid sites in the Western Isles? Almost certainly. Have a look for yourself in 2012.

 

First published January 2012. Photographs: Lee Thickett