starting a new flowering season

photo: Robert Crnković

In the Mediterranean, the new season is already in full blossom. From the Croatian island of Čiovo Robert Crnković sent me this photo of a Himantoglossum robertianum. It is flowering in the neighborhood of a splendid albiflora plant he found last year:

photo: Robert Crnković

Hypochrome forms of Neottia nidus-avis

Deutsche Botanische Monatsschrift, 1890

In a contribution for the Journal of European Orchids (Journal Europäischer Orchideen, vol. 50, 2-4, 2018, p. 221-226), Leslie Lewis presents an overview of the hypochrome forms of Neottia nidus-avis and new findings in England. In the introduction, she explains that these orchids have colour pigments – chlorophyll and carotinoids. However, colour variants are also occasionally found, the author writes.

Neottia nidus-avis f. nivea (Photo: Werner Hahn)
Deutsche Botanische Monatsschrift, 1891

It might be questionable ob these colour variants should have a taxonomic relevance. But at least there are scientific descriptions of such forms already in the 19th century, either as varietas (var.), forma (f.) or as lusus (lus.). Leslie Lewis presents those descriptions by Philipp Wilhelm Wirtgen (1806-1870),  Paul Wilhelm Magnus (1844-1914) and others. Following the Swiss botanist Gustav Hegi (1876-1932) she is presenting a consistent overview on the level of forms:

  • Neottia nidus-avis f. pallida: plants with pale yellow flowers
  • Neottia nidus-avis f. nivea: plants with snow-white flowers
  • Neottia nidus-avis f. sulphurea: plants with sulphur-yellow flowers

Calypso bulbosa forma albiflora

At the edge of the Arctic, Calypso bulbosa is one of the most Northern orchids. After snow smelting, from April to June, the plant is flowering in Northern Sweden or in Canada. It has rose to violet petals, the lip has a white or rose ground, with rose or violet spots. Albiflora forms are extremely rare.

In the Canadian National Park Banff, Jeroen Gerdes has found a white-flowered plant which still has its purplish color pattern in its hypochil. A purely white-flowered plant has been found this year by Marco Klueber in the Swedish province of Dalarna gefunden – here all the Anthocyanine pigments are vanished.  

The small plants grows in moist coniferous forests, on moss grounds. It’s a real dream to find it in this white-flowered form.

Orchid conference in Neumuehl: Rescue mission in Switzerland

An unusual rescue mission in the canton Zurich was subject of the 2018 orchids conference in Kehl-Neumuehl, Germany. In this Swiss region, nutrient-poor grassland and bright forests have been dramatically reduced, René Gaemperle explained. Reasons are – as in other regions – the over fertilization of the intense agriculture and the increased building activity: “Where the hills are most beautiful, country residences are built”, Gaemperle said.

In order to strengthen weak populations like Ophrys araneola, Gaemperle cooperated with officials and organized manual pollination, collection of seeds, mixture of seeds with river sand and sowing. If the appropriate symbiosis fungus is in soil, this method works rather soon, explained Gaemperle. The time from sowing to first flowering is just three to six years.

He chose a different method with Anacamptis coriophora: Seed capsules from the Lake constance habitat Wollmatinger Ried have been sent to an expert for in vitro culture in Sweden. The young plants have then been planted at seven places in canton Zurich, overall 525 plants until 2015. In this year 56 of those plants have flowered, Gaemperle told. When species are threatened by extinction, such methods are the only way to save them. “If we don’t act now, they will vanish forever.”

Threatened orchid species are also an issue for Peter Steinfeld who lectured about the nature reservate Bliesgau in the German state of Saarland. Steinfeld has been observing the changes of the regional flora for 35 years. According to him, Cephalanthera rubra is threatened by extinction in Saarland – he found the last flowering plants  in Bliesgau about 20 years ago. Heavily decreasing is also Dactylorhiza viridis. But Limodorum abortivum is expanding, probably coming from the French region of Lorraine. The same case is with Ophrys sphegodes and Orchis simia. As another “profiteer of climate change” Steinfeld named Himantoglossum hircinum. Climate change was also the subject of my lecture with impressions of this summer on Gotland, Sweden. Jean-Marc Haas also reported about dried out places in Uzbekistan.

At the conference with more than 60 participants from four countries, which was organized by Harald Baumgartner and Hubert Heitz, Helmuth Zelesny lectured about a field trip to the Golzentipp mountain in Eastern Tyrol, with colour variants of Nigritella rhellicani in white, yellow and carmine. In this region at the edges of the Lienz Dolomites Gymnadenia conopsea is also quite often white-flowered. Hybrids of both species display a big variety of forms. Not so common is the hybrid of Gymnadenia conopsea with Pseudorchis albida. Nigritella rubra is flowering on lime stone. The variety of the orchid flora on this Alpine meadows has also been described by Norbert Griebl in his paper published by AHO-Berichte.

Helmut Presser lectured about new taxons related to Ophrys holoserica and Ophrys scolopax in France as there are Ophrys demangei and Ophrys quercophila, the oak loving Ophrys. Hartmut Moeller again showed impressive photos of pollinators, this time he observed Epipactis palustris with potter wasps, bumblebees and beetles.

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.

Dactylorhiza incarnata

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.

Gymnadenia conopsea x Nigritella rhellicani with white flowers

In the latest edition of the Berichte aus den Arbeitskreisen Heimische Orchideen (Jg 34, Heft 2, 2017, S.123-145), Norbert Griebl presents the diversity of alpine orchid hybrids on the meadows of the Golzentipp mountain (2317 m) in Eastern Tirol. Among them there is also a white-flowered hybrid of Gymnadenia conopsea and Nigritella rhellicani (Gymnigritella suaveolens). Griebl views two possible options:

  • a white-flowered Nigritella rhellicani, which can be rarely found at the Golzentipp, and a white-flowered Gymnadenia conopsea, which is not rare in this region, have hybridized
  • a spontaneous mutation of a hybrid affecting the production of color pigments.

Griebl sees a higher probability for the second case. This is supported by the fact that there have been no reports of such an Albiflora hybrid in other regions with color varieties of Nigritella rhellicani and white-flowered Gymnadenia conopsea, for example on the Seiser Alm in Southern Tirol – though these Suaveolens hybrids can be regularly seen there.

Orchids “adapt” to colour preferences of pollinators

This hypothesis has been formulated by Hannes Paulus in a contribution for the latest edition of the Journal Europäischer Orchideen (Hannes F. Paulus: Zur Bestäubungsbiologie der Gattung Ophrys in Nordspanien: Freilandstudien an Ophrys aveyronensis, O. subinsectifera, O. riojana, O. vasconica und O. forestieri. J. Eur. Orchideen. 49 (3-4): 427-471).

In this article the author studies both populations of Ophrys aveyronensis in Southern France and Northern Spain – the last one termed as Ophrys aveyronensis subsp. vitorica. According to Paulus it is just one species, because both are pollinated by the bee Andrena hattorfiana.

Paulus points to the fact that this bee is specialised on the widow-flower (Knautia). The pink inflorescence of this plant has the same colour as the perigone, i.e. the sepals and petals, of Ophrys aveyronensis. The expert of Ophrys is stating: It can be expected that this is not just a mere chance but an adaptation to the main nourishing plant of the pollinator. Knautia shows at the same time more deeply pink flowers as flowers tending to white.

This evidence is confirming the approach to also look for other plants when we search for reasons why albiflora forms of different orchid species are more often in certain places.

Trip reports and expert debates

After 21 years, the Orchid Conference of Sundheim, Germany, has found a new place: About 50 participants met in Kehl-Neumuehl in the beginning of October, in a Protestant community centre, only a few kilometres away from the traditional meeting place in the old “Stierstall”. The history of the conference has been described by Werner Hahn in the latest edition of Berichte aus den Arbeitskreisen Heimische Orchideen (Jg. 34, Heft 1, 2017, S.234-237).

This year, the program focused on travelling reports from Iran (Jean-Marc Haas), Croatia/Greece (Stefan Hertel) and Israel (Helmut Presser). Jean-Marc showed findings of Ophrys zagrica in an altitude of 2300 metres, Ophrys khuzestanica and Ophrys strausii as well as Tulipa stapfys in the midst of dry pebble, Fritillaria imperialis or Iris acutiloba subsp. longipetalis. Stefan followed the transition of Ophrys incubacea to Ophrys mammosa and presented Ophrys cephalonica from the island Kephalonica with its long narrow sepals. In the beginning of March, Helmut has explored Mount Karmel and Mount Meron. Among the species which grow there are Ophrys carmelii and Orchis galilaea.

Typical for the delight of orchid scientists in disputes was a discussion after a lecture of Wolfgang Wucherpfennig. He stressed his criticism on the taxon Ophrys lutea var. subfusca for an orchid flowering in Northern Africa. The description of Heinrich Gustav Reichenbach in 1851 – along with two not so significant sketches – had resulted in the fact, “that the name subfusca has been used for many different species in the following years”. The situation which has been developed is quite disturbing. Wucherpfennig pleaded anew: “The name subfusca should not be used anymore but should be viewed as a nomen dubium.” But Karel Kreutz pointed out that a herbar finding in the Reichenbach collection which is indicated as “Ophrys fusca” should be viewed as the holotype of Ophrys lutea var. subfusca. And he stated that he has found according plants in Algeria – documented in his paper C.A.J. Kreutz/L.Lewis: Typification of Ophrys lutea var. subfusca Rchb. f., invalidity of the name Ophrys murbeckii H.Fleischmann. In: Journal Europäischer Orchideen Vol. 46, 1/2014.

The participants persued their discussion for a while – without answering the question why this detail of science history should be so relevant. In the long term, questions of the preservation of orchid species are much more important than any taxonomic debates.

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: