Dactylorhiza – albiflora

Albiflora orchids on Gotland

There have been a couple of botanical travel reports from Gotland with findings of white-flowered orchids, especially of Dactylorhiza incarnata. This year, I’ve finally visited this Baltic Sea island, in a quite warm and dry summer.

Such Dactylorhiza incarnata f. albiflora without any color hue have been quite rare – on my round trip by bike I’ve seen four plants. That translates into an estimated ratio of two or three per 1000 plants, which is quite the relation to be expected. Quite more often have been plants with a light yellow hue, although those could not always be addressed as the subspecies (or other taxonomic order) ochroleuca.

It was obvious that Dactylorhiza incarnata, possibly the orchid with the biggest population on Gotland, is occuring here in an marked color polymorphism – from white (very rare) to yellow (occasionally), light violet/pink (common) and the dark purple (common) flowers of the cruenta form which is sometimes viewed as a subspecies.

With Orchis mascula there have also been albiflora forms in the frequency to be expected from genetical mutations. In all those plants the pattern of purplish points in the flower lips has been preserved.

On a meadow near Oestergarn there was a beautiful white-flowered Gymnadenia conopsea among hundreds of plants..

Following a hint by Marco Klüber I also found an almost white-flowered Orchis spitzelii in a pine wood on the Northwestern coast. The color hue was still recognizable, the loss of pigments not as far reaching as here. But it’s still an indication that this orchid species also shows a genetical inclination to develop albiflora forms.

The dynamics of evolution on the Dactylorhiza meadow

Seven years after my first observations on a meadow in the valley of the small river Bieber in the northern region of the Spessart mountains I visit this special habitat again. The meadow with a wet trench in the middle is in full flowering. My estimation is that about 600 Dactylorhiza plants are flowering here: About 500 Dactylorhiza fuchsii, 50 already withered Dactylorhiza majalis and 50 hybrids Dactylorhiza fuchsii x majalis. Among the accompanying plants are Rhinanthus spec., Pedicularis palustris, Campanula patula and even a group of Arnica montana. Platanthera bifolia is just showing the first flowers.

Among the 500 Dactylorhiza fuchsii are about 400 plants with very bright flowers and a pattern of bright violet loops on the labellum. Furthermore, I count 22 albiflora forms with white flowers and non-spotted leafs. This is a rate of 4.4 per cent – much higher than you could expect if those were just spontaneous mutations. When I first visited this place on 20.6.2010 and 1.6.2012, there were less albiflora plants. Only about 80 of the 500 Dactylorhiza fuchsii have an intense violet colour. This meadow presumably has its own dynamics of evolution, developing increasingly bright forms of Dactylorhiza fuchsii.

There might be a relation with the learning experience of bees: With the earlier flowering Dactylorhiza majalis, many pollinators may have already made the experience that there is no nectar in the spur of violet orchid flowers. While developing brighter flowers, Dactylorhiza fuchsii might counteract this learning experience. Young honey bees still have to make this experience like this one on the flowers of the hybrid Dactylorhiza fuchsii x majalis:

Albiflora greeting from Lithuania

Before the end of the year I received special finding reports from Lithuania: Bernd Gliwa has found a white-flowered Dactylorhiza traunsteineri, only once in 2006. The location is in a lime marsh between Kaunas and Šiauliai. It’s quite remarkable that this Dactylorhiza species is quite rare to see with white-flowered forms.

Photo: Bernd Gliwa, 21/06/2011, near Dievogala/Lithuania

In this nature reserve he has also photographed this Dactylorhiza incarnata. In this area there are also Dactylorhiza incarnata subsp. ochroleuca (with W. Eccarius, Die Orchideengattung Dactylorhiza, 2016 it’s again a species of its own, D. ochroleuca), Dactylorhiza incarnata subsp. cruenta and Dactylorhiza majalis subsp. baltica.

Bernd Gliwa has also studied the dragonflies of Lithuania and just published a monograph about them: Lietuvos laumžirgiai.

Wolfgang Eccarius presents his genus monograph about Dactylorhiza

Following the benchmark books about the genera Anacamptis, Neotinea and Orchis (together with Horst Kretzschmar und Helga Dietrich, 2007) as well as a monograph about the genus Cypripedium (2009), Wolfgang Eccarius now has finished his long lasting work and has published a compendium about the Dactylorhiza orchids.

The book closes a big gap and covers a genus of orchids which is especially rich in species and quite widespread in Europe. As he has established in former publications, the author at first gives a comprehensive introduction before portraying 37 species and 46 subspecies. Eccarius explains his methodological approach and offers a summary of the research history, beginning with the plant book of Otto Brunfels published in 1534. The book abstains from giving a system to identify the species by morphological indicators. But a tree of the genus structure based on genetical research offers a good overview about the manifold Dactylorhiza orchids and their relations.

In his description, Eccarius has taken some main decisions. He abstains from describing varieties and forms, arguing that those terms are “highly problematic” with Dactylorhiza. “The main goal of the author was a genus structure wich matches logical principles as well as the needs of observations in the field.” He stresses that’s it’s more important to differentiate between the ten sections than defining species: “With Dactylorhiza, sections are much easier to define than species.” For example, the Fuchsiae form a section of their own, together with Dactylorhiza saccifera. The section of Majales comprise Dactylorhiza majalis, Dactylorhiza cordigera and Dactylorhiza elata.

Dactylorhiza majalis subsp. calcifugiens — Photo: Peter Zschunke, 16/06/2012, bei Glæde, Dänemark

It’s comprehensible that Eccarius views Coeloglossum viride as Dactylorhiza viridis. The Viridae are presented as a subgenus, in addition to the subgenus Dactylorhiza. Other taxonomic decisions are more thought provoking. For example when the yellowish Early Marsh Orchid no longer is a subspecies of Dactylorhiza incarnata, but an own species Dactylorhiza ochroleuca – because there are only very few hybrids between both “which justifies the treatment as a single species in the view of the author”.

Difficult are the explanations about the white flowering Dactylorhiza fuchsii in Ireland, which are elevated by Eccarius to the status of a subspecies – while most experts view the okelly taxon of Dactylorhiza fuchsii as a variety. And the morphological description of the author is not quite helpful in the field: “The subspecies is different by its lower growth” – while the photos show rather high plants. And: “The white color of flowers is shown by whole populations and not only by single plants.”

But this is also valid for Dactylorhiza majalis subsp. calcifugiens, which is presented by Eccarius only as a synonym to Dactylorhiza sphagnicola. The book shows a photo of a plant from the German region of Celle which seems to be an albiflora form of Dactylorhiza sphagnicola, but which is quite different form the calcifugiens population in Northern Denmark.

Quite useful are the explanations about Dactylorhiza maculata, which is presented as a west and northern European species, distributed also in Northern Africa and Northern Asia. The color of flower is described as especially variable, from pure white to a soft and light purple.

Eccarius understands the tendency to a color dimorphism (or polymorphism) which is typical for the genus as functionally relevant. With Dactylorhiza romana, sambucina or incarnata this phenomenon serves as a factor, “to avoid quick learning experiences of polinating insects”. This matches with the regionally different tendency of Dactylorhiza fuchsii to develop albiflora forms.

The new book makes big progress in understanding the Dactylorhiza orchids. But for a full perception there is still a lot of research necessary.

new year greetings from Croatian island Korčula

Starting into 2015 I received a nice mail from Mirjana and Nebojša Jeričević living on the Dalmatian island of Korčula. They sent me photos of albiflora forms of five species, Orchis quadripunctata (above), Anacamptis pyramidalis, Himantoglossum robertianum, Dactylorhiza romana and Orchis italica. Especially interesting are those of Dactylorhiza romana. Those plants show some light yellowish hue but are not as yellow as the common yellow form of this bi-coloured species. They are are growing among violet forms and it might be assumed that they are plants whose flowers should have been violet but lost the anthocyanins pigments.

Albiflora forms of Dactylorhiza saccifera and cordigera

Though Dactylorhiza fuchsii is developing albiflora forms more often than other European orchids, especially in certain regions (Ireland, some German regions), there are no mentions of white-flowered Dactylorhiza saccifera. Both species are diploid and related with each other. Exploring the marsh areas of the Smolikas mountain in mid-June in Northern Greece, I’ve seen this splendid Dactylorhiza saccifera f. albiflora on wet grounds, in a height of 1200 m, embedded in Marsh Horsetails (Equisetum palustre) and accompanied by Dactylorhiza baumanniana and Neottia ovata.

In the same area there was also a white-flowered Gymnadenia conopsea with a slight purple hue.

Another highlight of the field trip to Northern Greece: three white-flowered Dactylorhiza cordigera on a clearing in the Vitsi mountain range near Kastoria. Those were surrounded by more than 1,000 cordigera plants with their characteristic deep purple colour.

The picture of albiflora forms of late flowering orchids in Northern Greece was completed by a Dactylorhiza incarnata f. albiflora near the village of Chrisi:

Sundheim Orchid Conference 2012

Sundheimer Orchideenkonferenz
Two great publication projects about European orchids are being prepared which will meet high expectations. At the 16th Orchid Conference in Sundheim (near Kehl, Southwest Germany), Wolfgang Eccarius offered a first look into his project of a monography about the genus Dactylorhiza – the planned publication year will be 2015. Among the about 50 participants of the conference, coming from Germany, Switzerland, France and the Netherlands, was Karel Kreutz who is working on an opus of 6 to 7 volumes about all the orchids in Europe, which is expected to be published probanly in 2016.

At the beginning of the meeting, Helmut Baumann showed a series of impressive videos showing pollinators of different orchid species. Helmut Presser presented photos of his latest Greece journey, Peter Goelz showed pictures taken at two different locations of Ophrys kreutzii in Turkey and the Essink couple shared impressions from Rhodos.

In my contribution about “Colour polymorphism with Dactylorhiza – Evolution as a continuing process” I presented my studies about Dactylorhiza fuchsii and the calcifugiens location in Northern Danmark. After a partly controversial debate, Wolfgang Eccarius talked about the specific difficulties of his Dactylorhiza project. The common genetical methods to differentiate between species, such as the construction of cladograms by means of an analysis of the DNA’s ITS regions, may be used only with great caution in this case, he said. “This doesn’t function at all”, if a species has developed from two species. Therefore, he intends to base his book of about 600 pages on a rather broad concept of species. At the beginning, there was a comprehensive study of literature, including about 1100 protologues (original decriptions). “This fact alone implies that the nomenclature of this genus will be a giant challenge”, Eccarius said. In order to concentrate on the essentials, he only wants to present species and subspecies in length, without ignoring varieties. “I succeeded in looking into all typesheets”, Eccarius said – with one exception: “I’m still missing the typesheet of Dactylorhiza incarnata subsp. baumgartneriana. The typesheet cannot be found in Stuttgart, where it is said to be.” This subspecies, described by B. and H. Baumann, R. Lorenz and R. Peter in 2003, later described by Kreutz und Sebastian Sczepanski as Dactylorhiza kafiriana subsp. baumgartneriana, is named after Harald Baumgartner, the organiser of the Sundheim Orchid Conference.

Snap-shot of the evolution: preliminary report of albiflora studies

Peter Zschunke: Albiflora-Formen der Orchidaceae - mehr als eine Laune der Natur
Thanks to all the contributions to this project website albiflora.eu I’ve compiled a first paper about the white-coloured forms of orchids, published in Berichte aus den Arbeitskreisen Heimische Orchideen (1/2012, p. 141-170). Following a short overview about taxonomic aspects the relationship of flower colour and fertilizers are discussed. The main part considers the differences of albiflora forms with particular genera of orchids. The paper finishes with a discussion of high frequencies of albiflora forms with Dactylorhiza fuchsii in Western Ireland and certain regions in Germany. Where does random mutation ends and where begins an evolutionary process? One possible scenario might be that nectar deceptive orchids flowering earlier than Dactylorhiza fuchsii – as there are Orchis mascula or Dactylorhiza majalis – impart fertilizing insects the experience that flowers with a certain form and a purple colour don’t grant them any nectar. Thus, a colour change to white might be an advantage. The German language paper can be downloaded here.

In the bog of white orchids

Most orchid species don’t like acid boglands – but there are two rare exceptions: One is geographically widely distributed from Belgium to Northwestern Germany and Scandinavia and is mostly addressed as Dactylorhiza sphagnicola. The other grows only in the Danish region of Thy: Just a few hundred meters behind the coastline of the North Sea there is a population of white-flowered orchids which have been described by Henrik Ærenlund Pedersen as Dactylorhiza majalis subsp. calcifugiens (in: Nordic Journal of Botany, 2004). In 2007, Sebastian Sczepanski and Karel Kreutz argued it would be more appropriate to regard these plants as a subspecies to Dactylorhiza sphagnicola – while Pedersen und Mikael Hedrén are viewing sphagnicola only as another subspecies of Dactylorhiza majalis. Apart from colour, the morphological differences of the single flowers of Dactylorhiza majalis subsp. majalis (left), calcifugiens (middle) and sphagnicola (right) are difficult to discern:
The spur of Dactylorhiza sphagnicola is a bit longer than that of D. majalis subsp. calcifugiens. And the leaves of the latter are spreaded in a broader angle than those of D. sphagnicola:

The single flowers don’t show any hue of purple, even the pollinaria lack Anthocyanin. There is rather some yellowish hue in the center of the flower, slightly reminding of Dactylorhiza incarnata subsp. ochroleuca. In contrast to other populations of albiflora forms, e.g. with Dactylorhiza fuchsii, there are no gradual differences in the loss of colour pigments – all the plants are consistent in the white colour of their flowers.

Visiting the region, I found calcifugiens at two places, one near the small fisher village of Lild Strand with only three plants, the other further to the south at a bog called Nissekaer with about 150 plants. Surrounded by dunes this place is a natural depression (danish: “kaer”) with a length of about 1500 and a width of about 250 meters:
Google Earth image of Nissekaer
In mid-June the orchids are just in the beginning of flowering. Most Dactylorhiza majalis subsp. calcifugiens are growing at the edges of the wet places, not in the midst of them as it is the case with Dactylorhiza sphagnicola in the Venn moors in Belgium. And the calcifugiens plants are quite smaller, reaching just a height of up to 31 cm. Neighbouring plants are Sphagnum palustre, Equisetum fluviatile; Eriophorum angustifolium, Menyanthes trifoliata, Vaccinium oxycoccus, Calluna vulgaris, Trientalis europaea and even Drosera rotundifolia – most of those plants are clear indicators of acid soil. Among the shrubs there is the dominant Myrica gale, which is used by the brewery of the near-by town Thisted.

Some calcifugiens plants show a broader labellum, indicating a possible hybrid influence of Dactylorhiza maculata – similar to the sphagnicola plants of the Venn region.

Among all the white-flowered orchids in the Nissekaer bogland I found two purple-flowered plants which might be a hybrid of Dactylorhiza majalis subsp. calcifugiens and Dactylorhiza maculata (left) and a Dactylorhiza maculata still in buds (right):

As a visiting and possibly pollinating insect of Dactylorhiza majalis subsp. calcifugiens there was a species of the genus Syrphida – as I’ve seen also with Dactylorhiza sphagnicola in the Venn moor (left)

Vividly interacting: Dactylorhiza fuchsii and majalis

Orchid locations are constantly changing: On a meadow last visited in 2010, the number of Dactylorhiza fuchsii has been quite smaller this year. Now, there have been more Dactylorhiza majalis then before – and several hybrids of both species. These may have quite different forms: either short plants with the broad leaves of majalis (above) and brighter, fuchsii-like flowers with a broad labellum – or more elongated, with narrow leaves and purple flowers with a slightly broader labellum (down).
The Dactylorhiza fuchsii on this meadow which has both wet and dry areas are still quite bright, but most retain some purplish hue, at least in the pattern of the labellum. This time, an albiflora form of Dactylorhiza majalis was also flowering.