Identification from physical features of the Hybrid of Epipactis helleborine x Epipactis atrorubens (sometime called E.Schmalhauseneii) on (Hutton Roof Crags, Cumbria) (My personal study notes)


When you have 223 E.helleborines and 800 E.atrorubens lying almost next to one another in such a small area as 650x500 metre why on earth would you not expect hybridization of sorts from two of the same family genus!
Variance of helleborine maybe one thing,
but hybridization is a totally different and possible concept. 

Simple, probable identification diagnostics from shape of leaves, spiralling of leaves up the stem and the colour of the stem, the inflorescence and flower spiralling and bunching, denticulation features of leaf edges etc
(without dna or other scientific analysis), and only the use of a hand lens.
And the study of flower profile especially
towards the basal callus.

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Starting here with "Spiralling" of leaves around the stem

(Classic Epipactis helleborine, then going on to show examples of possible hybridization with Epipactis atrorubens)


first of all take a look here at the classic Epipactis helleborine (Broad leaved) and in particular the 
spiralling of the large leaves around the stem


Epipactis helleborine - showing a close up of the leaves spiralling up the stem
just as we have come to expect with helleborine. You see only one species (helleborine) within this example.


Above Suspected Epipactis schmalhauseneii (hybrid), you note at least 2 features of the hybrid, but good when compared against the earlier photo 
Click over to enlarge


(Above) A good example showing of a hybrid, with (chunky) leaves spiralling up the stem of the plant, which in turn may suggest some part (E.helleborine) with a E. Atrorubens plant. This feature is by no means conclusive and only shows in selective hybrids, usually plants which are robust. But this is a very important consideration.



Spiralling in both L and R photos
L = E. Helleborine (spiralling)     Centre = E.atrorubens ( NO spiralling and distichous)   R =  thought to be a probable (Hybrid) with chunky leaves and (spiralling)


Above we have good side by side examples of spiralling and non-spiralling leaves. In the first photo on the left is a typical classic E.helleborine, then in the centre photo we have a classic atrorubens which would not normally show any signs of spiralling just straight leaves shown on alternative opposite sides to the stem (distichous), but the photo on the right is a suspected hybrid. This photo shows probable hybridization in the make up between both the helleborine and atrorubens subsequently creating a "spiralling of the leaves up the stem" effect.

THIS SPIRALLING FEATURE CAN BE one of the aids to help with identification of a hybrid. Although it is not always the case, a lot of the suspected hybrids may not even have spiralling leaves going up the stem, whilst they may continue to show the alternative opposites leaves (distichous) eg: classic E.atrorubens profile, although some do show spiralling, a lot of it must depends on which parent takes the lead obviously with the spiralling effect you would suspect the parent to be the helleborine, whereby the atroruben parent will have been responsible for other signs in particular the flower. I personally give consideration to this id trait whilst also considering other factors in combination at the same time.


I also have included this further example below which again shows both the E. helleborine on the left and a possible (hybrid) on the right. Note the hybrid (in this particular case) shows a dark hairy stem, although I have found dark stemmed hybrids (on atroruben looking plants) to be in the minority of hi-vigour hybrids up here on Hutton Roof with the majority of probable hybrids showing with the LIGHT GREEN stem, which to me represents the possibility (and only a possibility) of hybridization from the E.helleborine parent, but I would like to go into far more detail on the stem colours variations and their importance in a later section of these pages.



Spiralling of leaves up the stem
left: E.helleborine and right is a probable hybrid

(Above) Also worth noting on the right hand photo (probable hybrid) it shows very concave dishy leaves, this concave feature can be seen only on occasional suspected high vigour suspected hybrid specimens and is certainly not a regular feature so for me would not be considered as a definite diagnostic aid, although it is certainly worthy of note that it crops up from time to time, and in some cases will usually result in a probable hybrid.



Another example of both spiralling together with strong bunched 

chunky leaves at the base of the hybrid plant on our 17a.
photo taken on 7th July 2017


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Another diagnostic aid for me can be large dishy (orbital) basal and lower leaves which you may see occasionally on hybrid specimens



These photos show Left = E. helleborine, Centre left - E. atrorubens, Centre right = probable hybrid, Right = probable hybrid.


The photos of the probable hybrids (two) are shown to have very large "DISHY" or even orbital basal and lower leaves which could yet again be a further example of hybridization between the E helleborine and the E atrorubens. I also like to measure the 2nd but more important the 3rd leaf up from the bottom and if I can measure 3" width at its centre (or broadest part), then for me this can also be a great indicator. Another factor worth adding to the diagnostic considerations with regards to the hybrid, BUT certainly not conclusive. The majority of probable hybrids that I see on HR would not have these strong features, and I personally would only ever use this as another tick towards the possibility of hybridization.

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Possible identification from 'bunched inflorescence' or flowers going to 3 or 4 sides of the stem


Bunched Inflorescence within vigorous hybrid specimens

Epipactis helleborine:  In the majority of specimens I have looked at I have noticed, in this species the flowers making up the inflorescence tend to be placed to at least 3 sides of the stem (and not 4 sides).
I have found that in occasional specimens you get flowers actually going to all 4 sides of the stem.  I wonder perhaps if this has something to do with the direct path of the sunlight alignment to the plant and in most cases the plant will offer one side into a shade position.  So from this I can determine that the 3 or 4 sided flower arrangement belongs to the helleborine and NOT the atrorubens in the normal scheme of things.

Epipactis atrorubens: In all specimens I have looked at the majority which show the flowers of this species to be set to two adjoining sides of the stem with the opposite two sides of the stem not offering any flowers in the same alignment. Although occasionally I do find atrorubens which may flower to more than 2 sides.

The Hybrid: The probable hybrid comes out in many inflorescence shapes and forms, but in the more vigorous hybrid specimens it can show the (atroruben type) flowers to be on 3 or even 4 sides of the stem.  This again is probably a feature which shows another typical with helleborine features within the probable hybrid make up.
As with other diagnostic features, this will only ever be the case in relatively few specimens and is certainly worth noting with confidence.
Although this cannot be considered as conclusive to all hybrids.  In fact most of the hybrid specimens DO NOT follow these features at all, this information relates to the more vigorous of specimens which are very few. I will shortly go on to discuss probable hybrid specimens of a far less vigorous stature. 

For now I would like to show you some examples with photographs of the more vigorous suspected hybrid specimens.

Specimens 15 and 16 (now 15a) showing a compacted inflorescence. This is a suspected hybrid (E. Schmalhauseneii)

Above photo shows suspected hybrids (E. schmalhauseneii) with a very compacted inflorescence (specimens 15 and 16). You may say that this takes on a E. helleborine type inflorescence with flowers to all 3 or 4 sides of the stem.  This particular example on No. 15 (left) is very unusual to this degree and I have only ever seen it pertaining to this particular family alone and not replicated anywhere else.  Most of the examples I get are more in line with the specimen 16 look which you see on the right hand side of the photo which shows the inflorescence more spaced especially between the vertical layers of flowers.

While I am showing and mentioning about the one-off family 15 with its compacted inflorescence. I also want to show you yet a better example of this over compact situation which applies to a new specimen now named as 15c which lies approx 30 yards away from specimens 15 and 16 in a South/S west direction. It would appear to me that this is without doubt a true descendent from that original family, the give away is without doubt the make-up of the plant together with its close proximity to the parent, yet this specimen is an even more densely flowered specimen. Here is a photo of that specimen.

Specimen 15c suspected hybrid
obvious spin off from the plant shown in the above photo.
                     
This is specimen 15c with an inflorescence containing no less than 62 flowers. This photo was taken in 2017 and sadly the day after the plant was taken down by a Brown Hare. In 2018 because of the early year drought weather it came through very stunted and gave up part way through its production.  In 2019 sadly the plant never even showed. I am pleased to report that in 2020 the plant is back with us
(see photo below). yet in mid June 2020 the plant and its partner fell victim of browsing.

I am pleased to report that the plant came through OK in 2021 and matured to full ovary maturing and dispersal of seed. 


Hybrid Spec 15c on 20th May 2020

Here (below) is hybrid specimen 100 which has 65 compacted flowers going to all sides of its stem.   You immediately see the spiralling of leaves and their size and the very large lower bracts etc. 




You have now seen with the above examples of the most compacted inflorescence you are ever likely to see in a suspected hybrid, and although this is worth bearing in mind, it should have little bearing on what you might experience in a general situation.

The more regular type of inflorescence you will get in the more vigorous probable hybrids are shown below. Please note the flowers to at least 3 sides of the stem.

Hybrid Specimen No. 8
Hutton Roof Crags

And here is another one for example

probable hybrid specimen 4

This above is an interesting probable hybrid specimen which we have on Hutton Roof and is very dark (hyperchromic look) and what makes this even more interesting that it is one of the rarer specimens that actually do have flowers going all around the stem (4 sides).
So now I want to do a showing of a typical hybrid inflorescence against a classic atrorubens inflorescence side by side.

Above is typical of a vigorous probable hybrid v atrorubens
Left Specimen 8 vigorous probable hybrid, Cent: Spec 8 vigorous probable hybrid, Right: Classic atrorubens


I have now gone through my notes in regards to the Inflorescence in connection with “vigorous” specimens of probable E. schmalhauseneii (hybrid) and tried to show the differences against a classic atrorubens eg: spiralling of flowers around the stem.  I do intend shortly to do comparisons with the less vigorous suspected hybrids. 

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Stem Colour Variations

For me one of the pointers toward possible hybrid diagnosis may lie partially in the LIGHT GREEN stem varieties, which I feel may go a long way in favour of possible hybridization, though this remains to be confirmed either way.

As far as Hutton Roof is concerned I surveyed the areas for at least two years back in 2012/2013, before I actually found my first light green stemmed atrorubens which is shown here. So that alone tells you just how rare they were back in 2012.


My very first "light green stemmed" found in 2013 on Hybrid Hill, Hutton Roof

Most of the regular classic atroruben stems will fall into the following colour categories eg: dark brown/purple to medium and very occasionally even light colour variations or they will take on the very dark dirty green colour through to medium variations.  Here in the next photo you see some examples of these regular colour variations....


Variant stem colours within Classic atrorubens
Top: dirty green through to mid green 
Bottom: Dark Brown/Purple through to mid and even light brown.




Above is an example of a specimen I checked on 23rd June 2020 and 90% of which showed a purple stem as you may expect with a classic Atrorubens, but when I looked close I noticed it showed some light green showing through which I personally would consider possible helleborine throwback.  It is so important that these differences be noticed and taken into consideration, THEY ARE IMPORTANT!


17a possible hybrid shows here a mixed stem on the right photo
You will see the bottom of the stem shows at the top to be glabrous and quickly changing into a hirsute (hairy) stem, Again important and invaluable signs of possible hybridization interaction.
7th July 2017


The above photo shows 17a which is a considered possible hybrid which in 2017 showed leaf compression as you see in this photo, but probably as interesting when you look close is the stem of which you note the bottom part is hirsute whilst 75% of the upper stem is Glabrous - a very mixed picture, these again are probabilities.

The next photos (below) show typical Epipactis helleborine which always show a very light green stem . You do get variant light shades of green but this is typical of a LIGHT GREEN RANGE and can be noted similar to the four photos I have included here.


Typical LIGHT GREEN variations in the stems of Epipactis helleborine

In the next photograph I will show some VERY LIGHT GREEN STEM variant specimens of probable hybrids (or for that matter light green stemmed atrorubens, if there could ever be such a thing! what a difference from the photos of the classic atrorubens shown earlier. 

This light green could well be yet another factor of E.helleborine/E.atrorubens hybridization with a prime factor of E. Helleborine taking over the stem properties of a otherwise atrorubens flower led plants. Most of these examples shown below I have already considered to be possible hybrids



So I give considerations when I see a very light green stem showing on a atroruben type flowered plant because these can be the first and best indications of the start to probable hybridization of sorts, although like I keep on saying, there is still no definitive, it is only another aid to try and help with diagnostics of the hybrid 

So summing up, the VERY LIGHT GREEN stems on a (atroruben type flower) led plant gives me a strong suspicion that hybridization may well have taken place and subsequently there maybe the probability of a hybrid influence, YET this is only part of the story because occasionally odd DARK stems may also be considered to be candidates for possible hybrids as well, yet so early on in my research, I have only ever had a couple of these to consider.

So it's just another factor to be considered when trying to diagnose the hybrid

Finally one other consideration worth bearing in mind. On Hutton Roof we do have the rare "Pallens or pale forms" which are considered a variety of atrorubens. Now all the specimens of Pallens do have LIGHT GREEN STEMS typical of what we have already mentioned above. So I wonder just what we may be dealing with here! eg: are they really a variety (and not a type of hybrid) or are they some sort of leucistic plant? For now personally I am not bringing these varieties into the equasion. They are only but a light or pallid formed variety!!  


Photos of the variety "Pallens" which we have on Hutton Roof

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Another great supportive aid for identification can be by using leaf edge "denticulation"...........

I have been very fortunate over the years to have had the privilege of a further aide to help me with supportive evidence in identification and that's been from previous work already carried out by both Sean Cole and also by Mike Wilcox in their own individual studies. 



The first photo I show will be the regular "Atrorubens" which here you can see in colour, 


40x Denticulation photo of "atrorubens" used as a supportive aid to identification (photo: Sean Cole)

With atrorubens you can see the teeth pattern are pretty regular and not only that they do bear a double layer of teeth if you look very close. It is also clear that you can see a line of "purple" colour showing to the bottom of the teeth (this of course is the "Red" trade mark which you should note is not seen on the following helleborine photo.  Please note the red will disappear with ageing.



So this next photo is the Epipactis Helleborine denticulation photo:


A x40 denticulation photo of E. Helleborine kindly shared by Sean Cole


With E. Helleborine which you can see in the above photo the teeth pattern is much more uneven with odd individual teeth or even small cluster rows appearing amidst a more regular section etc.  Also you do not usually see the line of "purple" which is associated more with the atrorubens. You tend to associate the denticulation with transparency!



And finally I want to show a photo of what maybe a Schmalhauseneii hybrid and again a photo to help me in a supportive roll of trying to obtain identification.



x40 denticulation of  possible E. Schmallhausenii.  Photo kindly shared by Sean Cole


And finally from the photo above you will see that it represents a more or less "in between of the previous two photos.  The teeth are irregular but will get more regular rows in between the protruding teeth like we had with the atrorubens.  Also if you do look very close again you should see a double row of teeth.  Also sometimes but very rarely on the hybrid you can see a trace of purple colour at the bottom of the teeth (in 90% of cases they will be transparent like you get in E. Helleborine).

One point worth mentioning is that if samples are collected the red wash will leave the sample which will show as transparency with ageing.

I am also very fortunate to have the following photos from Mike Wilcox which also show "denticulation (teeth patterns on leaf edges)" features:






This is yet another examble of "denticulation" of the E. Helleborine (Photo: Mike Wilcox)



Basal leaf structure in a possible hybrid showing some red/purple staining.
from my diaries 21st July 2014
(please click over the photo to enlarge)


Other factors of possible hybridization indicators I am currently checking out are:

Purple hairy Ovaries showing small sections of light green glabrous patches throughout the ovary.

Stems showing green and light green mix with both hairy and glabrous mixture.

Another diagnosis feature can be the flower itself, especially in regards to the basal callus (callosity).

The Hybrid – by the basal callosity

I have already mentioned several key points which clearly show the probability of “the hybrid”, by now most of these points can actually be shown within the field.

But now I want to turn to yet another factor which we have not previously mentioned and for me could be added to the list of “ticking the boxes”. It is subtle and needs to be looked at with care and hopefully when mastered can be added to your list of diagnostics towards a hybrid.

We are going to take a close look at the actual flower which all seem to have their own particular fingerprints, but lets be more general and look in particular at the boss at the base of the flower.  With the helleborine you see two raised callus (two little humps), yet with the atrorubens you will see the bosses covered in a frill (roughness to the callus). So that’s all normal but sometimes things are not just how you would expect them.

On numerous occasions I see the bosses to be a in between.  So I am looking at what may at first look just like a atrorubens yet when I look more closely at the flower I see this in-between look eg: the callus are in part smooth whilst the other part is rough or frilled. 



This sketch shows you what you can expect with the hybrid which clearly shows a in-between situation with the bosses eg: half helleborine and half atrorubens - half smooth and half frilly



Here the example shown in both the above and below photo shows two hybrids top is 100 and the bottom one is 17q.  If you do look close at the bosses you will see part of one parent against part of the other parent.  This will not always be seen immediately you do need to inspect all flowers, but with the hybrid there are usually one or more examples on the same inflorescence. But do not be disappointed if you cannot find it!

(below) shows it to you relatively "EASY". This is our rare beautiful Specimen 66


Click over to enlarge and note the bosses!