Albiflora couple in the valley of Kinzig

With Orchis mascula, the albiflora forms are not rare. But in many cases the pattern of violet points is preserved in the lips – even if the production of Anthocyanin is disturbed, the last reserves are obviously kept for this pattern. This year, a pair of Orchis mascula was flowering entirely white in the valley of Kinzig (in Hesse, Germany): Orchis mascula

The leaves of these plants are unspotted, while the violet-flowered Orchis mascula often have intense spots.

Nearby, Orchis purpurea was beginning to flower. The third orchid species on this meadow in the “Schdänerer Weiberch”, as it is called in the Hesse idiom at the beginning of the path, is Himantoglossum hircinum. In May, the lizard orchid is just beginning to develop its inflorescence.

A bit further on the path, at the edge of a small forest, there was another albiflora form of Orchis mascula, also without any violet color in the flower, but with a marked green stigmatic lobe. The green hue is also preserved in the spur.

Orchis_mascula f. albiflora

Orchis mascula f. albiflora

(with many thanks to Matthias Raschka for indicating me the location)

The dynamics of evolution on the Dactylorhiza meadow

Dactylorhiza fuchsii f. albiflora

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.

Dactylorhiza fuchsii f. albiflora

Dactylorhiza fuchsii f. albiflora

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:

Vividly interacting: Dactylorhiza fuchsii and majalis

Dactylorhiza fuchsii x majalisOrchid 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).
Dactylorhiza fuchsii x majalisThe 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.
Dactylorhiza majalis f. albiflora
Dactylorhiza majalis f. albiflora

Three albino plants of Cephalanthera damasonium

Cephalanthera damasonium It is well studied that Cephalanthera damasonium belongs to those orchids which can live without chlorophyllum – together with other species of the tribe of Neottieae or the genus Epipactis. While exploring a mixed forest near Lahnstein (Rhineland-Palatinate) together with Ingo Beller of the Arbeitskreis Heimische Orchideen (AHO) Rheinland-Pfalz, we found a group of three albino plants in addition to three green-leafed Cephalanthera damasonium. Of the apochromic plants one has two flowers, one only one flower and one has no flower. Those albino plants receive their organic carbon with the help of fungi. A study of V. Tranchida-Lombardo, M. Roy, E. Bugot, G. Santoro, Ü.Püttsepp, M. Selosse and S. Cozzolino, published in 2010 in Plant Biology suggests that the albino Cephalanthera damasonium may be viewed as “an intermediate step in the evolutionary emergence of mycoheterotrophy”, or of the ability to be nourished both by fungi and photosynthesis. By means of genetic analyses the authors declare: “Albinos could be either permanent mutants, as suggested by phenotype stability over the years, or transitory phenotypic stages, in which genes involved in the photosynthetic pathway can switch off depending on micro-environmental conditions (e.g., the amount of C resources provided by the nearby fungal mycelia or tree roots) that prevent greening.”

Mass population of Dactylorhiza fuchsii f. albiflora

Dactylorhiza fuchsii f. albiflora

In addition to the Irish region of The Burren and the Hesse location of Biebergemuend there is a further location where Dactylorhiza fuchsii tends to white-flowered forms in big numbers: In a birch grove near the village of Wolken in the upper Moselle valley there are several hundred plants with a clear trend to bright and white flowers. A count of a random sample resulted in 13 per cent of white flowers without any markings on the labellum. Further 38 per cent of the plants have a white base colour with pink marks. The differences in flower colours correspond with the results found in the other two regions and are even a little bit more accentuated. These results may give further evidence to the assumption that Dactylorhiza fuchsii is in the midst of an evolutionary process which also changes the phenotype of the species.

Percentages of flower colours in different locations
different locations of Dactylorhiza fuchsii

The following tableau shows the wide range of fuchsii flowers found on that location. The brightest forms also lack the Anthocyanine pigments in the pollinaria as the lowest row of examples and the following macro photo demonstrate.
Dactylorhiza fuchsii

Dactylorhiza fuchsii f. albiflora

The only other orchids in the forest are Platanthera chlorantha and an Epipactis spec. – while in the other two locations with abundant albiflora forms of Dactylorhiza fuchsii there are also the earlier flowering Orchis mascula (Burren) and Dactylorhiza majalis (Biebergemuend), both flowering in pink and both – as well as Dactylorhiza fuchsii – trying to attract pollinators with nectar deception. Among other plants in the birch forest, a former gravel-pit and now a nature reserve called “Kuhstiebel”, are Orthilia secunda, Fragaria vesca and Tussilago farfara. But the dominating plant there as well as in a nearby marsh area is Dactylorhiza fuchsii with mostly spotted leaves – even in the case of the white-flowered plants: Dactylorhiza fuchsii f. albiflora

Colour matters – a spider’s relationship with Cypripedium calceolus

Cypripedium calceolus with Misumena vatia

Misumena vatia, a crab spider has developed a special relationship with orchids. Sitting on an albiflora form of Dactylorhiza fuchsii it wears its white body, as Norbert Griebl has observed. Now I’ve watched her in Thuringia on Cypripedium calceolus in its yellow form – a perfect mimicry. The spider makes use of the fact that the slipper-shaped pouch of the plant traps small insects in order to ensure its fertilization – while is spider is only interested in food.

The spider changes its colour by secreting a yellow pigment into the outer cell layer of its body.While sitting on white flowers, this pigment is transported into lower layers. The colour change from white to yellow takes between 10 and 25 days, the reverse about six days.

The Cypripedium calceolus in Thuringia show almost none varieties in terms of flower colours. Among more than 1000 plants I’ve found one with reduced anthocyanin pigments in sepals and petals which could be addressed as Cypripedium calceolus forma citrinum.

Cypripedium calceolus f. citrinum

Cephalanthera rubra f. albiflora revisited

Cephalanthera rubraThis year I had the chance to visit the white flowering form of Cephalanthera rubra in the Hesse part of the Rhoen some days earlier than last year. But first I followed a hint and looked up a place further in the South, near Ahlersbach. Quite near a path through the forest a white Cephalanthera rubra with a slight hue of pink! The pink colour is well visible in the buds, where the remaining pigments are more concentrated than in the opened flower.

Cephalanthera rubraAt the second place near Huenfeld, characterized by an old beech mentioned by Marco Klueber in his great book about “Orchids in the Rhoen” the albiflora plants of Cephalanthera rubra are splendidly flowering. The Swedish botanist L. Anders Nilsson showed (in an article in Nature, 1984) that Cephalanthera rubra mimics the floral coloration of Campanula in the visual system of bees in order to be pollinated by them, especially by male bees of the genus Chelostoma. Since Cephalanthera rubra is flowering before Campanula, they are quite attractive for the bees. It would be interesting to see how bees are reacting to the albiflora forms of Cephalanthera rubra.

With regard to pollinators my visit on June 24th had a special highlight when I saw a wasp (Argogorytes mystaceus) pollinating Ophrys insectifera. The insect pseudocopulated two flowers in a timeframe of more than seven minutes.

Even more fuchsii diversity

Dactylorhiza fuchsiiDactylorhiza fuchsiiSimilar to The Burren there are also some continental locations where Dactylorhiza fuchsii tends to develop white or at least bright flowers. In the Belgian province of Liège, near Lanaye, there are dozens of albiflora forms of this species, as Jeroen Gerdes told me – he sent me the photo at the left.

Today I visited a meadow near Biebergemuend in the Hesse part of the mountain range called Spessart. On a space of about 5,000 square meters I counted about 300 Dactylorhiza fuchsii with the following distribution of flower colours (in per cent):

Dactylorhiza fuchsii with %
dark pink flowers 2
medium pink flowers 6
bright pink flowers 45
white flowers and labellum marking 44
white flowers without marking 3
total 100

In total 10 of about 300 Dactylorhiza fuchsii are albiflora forms – such a frequency is quite higher than usually observed with this or other orchids species and leads to the assumption that there might be some gradual or saltational evolution under way.

Dactylorhiza fuchsii x majalis Among the other plants in this area I noted Dactylorhiza majalis (withered), Dactylorhiza fuchsii x majalis, Platanthera bifolia, Neottia ovata, Rhinanthus minor, Cirsium arvense, Campanula persicifolia, Picris hieracioides and Arnica montana. Dactylorhiza majalis grows in the neighbourhood of wet ditches along the meadow – and there are also hybrids of D. majalis and D. fuchsii – still flowering while D. majalis is already withered. The hybrids are rather strong, some of them with a height of up to 50 cm. They can easily be determined by their broad leaves and the rounded labellum of the flowers with a reduced medium lobe. There is also an albiflora form of Dactylorhiza fuchsii x majalis (right).

Partial albiflora form with Dactylorhiza majalis

Dactylorhiza majalis
Studying a marsh with about 2,000 Broad-Leaved Marsh Orchids (Dactylorhiza majalis) at the Southern edge of the Rhoen region in Germany I saw a group of three albiflora plants together with Menyanthes trifoliata, Caltha palustris and other marsh plants. Even more interesting was another albiflora plant in a distance of about 40 meters with an orchid in its direct neighbourhood showing a kind of partial albiflora: Most of its flowers have the standard purple colour but some flowers are partly purple, partly white – either in the lip or in the petals.
Dactylorhiza majalisObviously, the genetic allele containing information for the albiflora form has plaid a certain role for this plant – but it was dominated by the DNA, which contains the information for the standard colour. This observation as well as a similar one in Southern France with Anacamptis morio poses questions about the recessive character of the albiflora allele. There might be some cases where the albiflora allele of one parent plant is not totally restrained by the dominant purple allele of the other parent plant which results in such purple and white spotted flowers. Before I continued the trip to a charming meadow with hundreds of Anacamptis morio (among them two albiflora) and Orchis mascula I made use of the rising morning sun to make some more photos of the Dactylorhiza majalis f. albiflora trio: Dactylorhiza majalis

birth announcement

Orchis militaris
It seems to be a good year for Orchis militaris – the meadows in biking distance from Frankfurt are full with violet inflorescences. And this time, in the fifth year of continous observation, there is a second albiflora form of an Orchis militaris, just ten meters away from the place of the first plant. It has a height of 20 cm, a rosette of three leaves and about ten flowers. The reproduction of albiflora forms is difficult, since the DNA sequence responsible for the lack of flower pigments is recessive, but here it has obviously happened. The first albiflora plant is about 30 cm tall, with five foliage leaves and about 25 flowers:
Orchis militaris