Prolonged dry weather affecting Epipactis atrorubens etc etc etc


Prolonged dry weather affecting Epipactis atrorubens and Epipactis helleborine and their hybrid, sometimes known as Epipactis schmalhauseneii. Together with notes on the established growth and current status of known Epipactis varietal forms PallensBicolor and others on Hutton Roof, Cumbria, UK. 
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My orchid study area on Hutton Roof is a small part of the Crags within an area comprising of some 650 x 500 metre approx. In most years we will get up to 800 Epipactis atrorubens and around 223 Epipactis helleborines, together with up to 12 to 15 hi-vigour hybrids also known as Epipactis schmalhauseneii.
This year (2020) recorded counts show that we have 618 Epipactis atrorubens (of which 138 were predated) and 223 Epipactis helleborines (of which 39 were predated).  There has been a drop in numbers with the regular E.atrorubens. But also quite a large drop in numbers of all plants regarded to be of a hi-vigour status eg: hybrids and E.helleborines.
The decrease in numbers combined with other factors first became noticeable to me back in 2018 when abrupt weather patterns brought about prolonged dry weather during the month of May and June which subsequently in turn caused a drought just at the very time when the orchids needed water at their most. The outcome resulted in quite a lot of plants came through initially, but then gave up growing half way through their growing cycle and we were left with some of the plants showing drooping inflorescence, which never straightened and just then went on to wither away with time. This premature dieback seemed to be at its greatest towards the end of June and affected quite a large amount of the total number of plants.
Still lots of plants did mature and came through as what appeared normal.  I can only guess that the ones that did die premature must have been cited in areas were moisture was at its lowest.  
Continuing into 2019, I was still seeing plenty of problems with some of our orchids eg: Some of the established plants not coming through and some of the ones that were coming through appeared to be of stunted growth. The problems seemed noticeable to at least 25% of the plants within the survey area.
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Moving on into 2020, the whole situation was further compounded by yet again dry weather during the important months of April and May, although we did have quite a lot of plants that did come through and reached maturity, but we also had lots of plants which just gave up the ghost and never even came through.  Of particular interest this year we did not have any specimens coming through and giving up half way through their cycle (premature dieback – inflorescence drooping and withering away). Not one example of this was recorded, although we did suffer many losses of plants.
The most noticeable problems we seem to have had this year was that most of our hi-vigour hybrids, together with some of the hi-vigour tall helleborines just did not appear.  Out of the dozen or so established hybrids on this fell, only two survived maturity this year which were Specimen 11 and Specimen 70 and only ten of the very large (up to one metre) sized helleborines came through. Normally I would see perhaps 30 of the large hi-vigour helleborine specimens, yet I did see lots more of the medium and very small sized helleborine specimens.  I also noticed this year in particular that we had many more of the first year seedlings coming through in all areas, the majority of these were atrorubens as you would expect.

Our hybrid search history studies from Hybrid Hill and Ingleborough View on Hutton Roof                                                                                               
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I started searching for the hybrid somewhere back in 2011 and began my searches from the areas I was soon to nickname “Hybrid Hill” and its opposite pavement which I called “Ingleborough View”. I received help surveying at the time from Alan Gendle. We did manage to locate several plants which at that time we considered to be probable hybrids, simply because of their large vigour and visible identifiers.
Of particular note, I remember seeing my very first light green stemmed atroruben specimen back in 2013, which seemed so unusual and at that time probably was. I took photographs of the specimen which was a plant well distorted! You can see from the photograph shown below.                              
I want to mention this particular plant just to place on record that I had never seen a light green stemmed atrorubens before on any of these pavements and that was over a period of some two years searching out the hybrid, so I guess the LIGHT GREEN stemmed variety just had to be a very rare sight on Hutton Roof and little did I know at the time this was to become more of a sought after varietal form as time went on.
I have been back on both Hybrid Hill and Ingleborough View (last time 18th July 2020) and checked out the areas were we had previously found up to 7 considered hybrids at the time, and nothing could be found of them or clues to their previous existence. I can only presume that again the drought weather conditions affected these once magnificent plants. Although I would like to mention that with these hybrids, some do seem to disappear after only a few years, I guess it’s a sign of natural order.

Establishing my future study area on the Western slopes of Hutton Roof  

Moving on, it was back in 2014 when I received a notification from the then Cumbria Wildlife Trust warden that he and others had seen some very special hi-vigour orchid plants at the top of the West slopes of Hutton Roof and suggesting that I should go and view them. It’s an area known to me which I had checked out several times previous to hearing this but never really found anything striking there on my previous visits. Yet I am so pleased I followed up on this particular lead because what I was about to find was truly amazing and has continued to be ever since by totally immersing my interest and energies in these special orchids.

Measuring the widths of boss against epichile on Epipactis atrorubens

Going back to these early days and most years since Alan Gendle came up to Hutton Roof and helped me with trying to establish what possible hybrids we had on the nearby fells, those days we tried to get a diagnosis for hybrid (or schmalhauseneii) mainly by using BSBI crib info, eg: measuring atroruben flowers with low widths of bosses which had to show to be less than 50% of the width of the epichile. together with any other additional pointers we could find on the actual plant. Some of the tall (up to one metre) specimens gave you a feel of hybrid straight away before even looking for other pointers, something just seemed to stand out and hit you. We did manage to establish that we may have had anywhere up to about 15 probable hybrids on the fell at the time, but some of these fell into debate at times as you would expect.  One thing that did become essential if the hybrid was to be found was to give up on the boss versus epichile measure earlier mentioned and to start taking into consideration the very large wide epichile and boss specimens which seem to stand out and looked like hybrids. Once we got in this frame of mind it did become easier to spot them.

The very recent high presence of “Light Green” Stems on our Atrorubens and their spread in numbers

When we started checking the new study area from back in 2014 and up until say 2016/17 we would only ever find maybe the odd single specimen which showed a true light green stem. It just was not anything to be seriously considered at that time simply because we had no volume to back it up, just purely the occasional specimen.  But all this was about to change and from about 2016/2017 when the light green stem specimens have grown considerably each year and more so in the latter years to a situation where we now have somewhere in the region of at least 30-35 of these low vigour atroruben light green stemmed specimens throughout the study area and also being now found on other areas of Hutton Roof as well. Most of the plants range in size from about 8” to 10” generally, although some are now at varying sizes and even up to about 18”. When the increase in numbers began we also started to take these plants far more serious, and that was from about 2017 when we started to see their spread and we have always held the belief that there is possible introgression of sorts within most of these “light green” plants. But for now I will still classify them as an atrorubens variety with a big question mark.

The very first Atroruben “Pallens” and their spread in numbers in most years

It was again 2014 when both Alan and I discovered our first Pallens plant on Hutton Roof and since then numbers have grown to over 11 Pallens specimens situated at various points of the study area. There are vast differences between the plants with colour ranging from a Pallid yellow to a very strong brilliant yellow, some show spotting or dappling of red (atrorubens) whilst others do not show any red other than a slight wash over the outer sepals. Most of them have been reliable and come through in most recent years, but sadly again in 2020 we have only had 3 mature to flowering.  Again I do think this could be down to both predators and also part dehydration playing a major part in their non-appearance. Sadly I don’t have any histories prior to 2014 for comparisons.
As yet we have not found any more from different areas of Hutton Roof, although I am grateful to Greg from Leicestershire who has kindly put me onto one he saw on Uberash Roughs of which he passed on details back in 2019, which I did follow up in that year and again this year (2020), but by the time I got there out of all the atrorubens present the one and only special “light green” stemmed had already had their inflorescence removed by Brown Hare.  
                  
Establishing Atrorubens “bicolor” and their spread in numbers since

The bicolor for me began in July 2014 when I wrongly diagnosed the three specimens I had which had two of them on my regular study area and a further specimen on the nearby Two Swans pavements.  I started to call these three red sepalled and yellow petalled forms “Lutescens” which turned out to be a totally wrong diagnosis and with time this was amended to their correct diagnosis of bicolor (previous Lemon Petalled).
So on correction the very first bicolor specimen I found was close to the area of the first Pallens, and the interesting thing was it had red sepals with yellow petals yet with an extraordinary epichile and bosses which were cream.  The size of this particular specimen then was about 12” and it has not got any bigger over the last six years. It still comes up strong and still retains the white epichile and bosses but never gains any additional height.
The second true bicolor I found was further over to the north west of the study area and now heads the 55 population with its own 55 designation, but in 2014 it was only at about 14” high and has grown annually, and now it is almost one metre in size.  The point I mention all this for is to indicate that in 2014 these two were the only specimens of bicolor within my study area.  Today in 2020 we have over 30 recorded bicolors and lots more which are on their way.

A further Epipactis species for now called the “Westmorlandii” and probably of the family “Phyllanthes” has been present on Hutton Roof

A beautiful little plant that I first discovered back on 23rd July 2014. Unlike other helleborines seen before on Hutton Roof and after lots of both on site visual and online debate the census of opinion think it is probably a member of the Epipactis phyllanthes order, although the variety is still a question of ongoing debate.  It is so unusual and it has been suggested that it could belong to the sub-form “confuse”. The plant has always been very frail and dainty and never really getting established from year to year, although it does seem to make the effort every now and again eg: up one year and then missing for a year or so.  When it does come through it is such a weak little plant. I have shown a photo below of when the plant look at its very best back in 2014.

Hi-vigour Epipactis helleborine plants with darkened stems which look like a mid brown colour to variant dark green colour and showing a lighter green bleeding through in parts.

It was about four years ago (2016) that I first noticed we had a helleborine plant which had a dark stem and as come through annually. But this year (2020) I have discovered a further four of these darkened stemmed plants in an area of approx. 50 metres diameter. These plants may well have been there back in 2016, I have no history on them, but they are proving to be of special interest. After lots of consideration to the diagnostic pointers I am of the strong belief that these plants may well be hybrids and seem to contain lots of possible hybridization pointers. It is seen by the following diagnostic points: Excessive hairiness on stem, ovary and peduncles, dark brown/green staining to the stem in blotchy sequence, dark staining on edge lines to closed and open buds of lateral sepals, heavy crennulations to the edges of the epichile. And possibly the layout of the flowers to the stem (in profile).


This was my very first "green stemmed" atrorubens found after two years searching 
Photo: Hybrid Hill 2014

This was my very first Pallens which
both Alan Gendle and I found on Hutton Roof, July 2014

This was mistakenly diagnosed as a Lutescens which should
have been a bicolor - July 2014 (only the 2nd bicolor found on Hutton Roof)  


(above) This was the very first E.atrorubens "bicolor" I had found back in 2014


above: Westmorlandii (thought to be a E.Phyllanthes)
Photo: 29th July 2016


A hybrid "Dark Stemmed"
found and photographed 3rd August 2020


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Notes published here on 4th August 2020
Bryan Yorke