Taxonomy – a proposal for albiflora forms of orchids

In a contribution for the journal Berichte aus den Arbeitskreisen Heimische Orchideen (Peter Zschunke: Von “alba” bis “viridiflora” – zur Taxonomie und Biologie hypochromer Orchideen. In: Berichte aus den Arbeitskreisen Heimischer Orchideen 38 (1), 2021. S. 78-99) I studied the question, how albiflora forms of orchids should be addressed in a scientifically correct way. In the past, botanists have been quite inventive to describe such plants with different names and on different taxonomic levels – even up to subspecies. But there is “no need to introduce a taxon in case of an individual genetic disorder as it is the case when the development of Pigments is disturbed”. Instead I propose, “to address all individuums of orchid species with a visible genetic disorder of the development of pigments as albiflora forms, with no need of a formal description while using the most common term in descriptions and with a general understanding of the term form as a ‘nomen nudum’, which does not require a typus.”

Orchids in Rhineland-Palatinate

One year after the publication of a new edition of “Orchideen in Hessen” by Heinrich Blatt, released by the Arbeitskreis Heimische Orchideen (AHO) Hessen, a first monograph about two German states in the neighborhood has been published: “Die wildwachsenden Orchideen in Rheinland-Pfalz und im Saarland“. In Coblence, six of the eight authors took part in the first presentation of the new book, honoring the 40-year-anniversary of AHO Rheinland-Pfalz/Saarland. Among them was the chairman of the AHO club, Juergen Passin (3. from right).

The book about Rhineland-Palatinate also shows several albiflora forms as Anacamptis morio, Anacamptis pyramidalis, Dactylorhiza incarnata, Dactylorhiza maculata, Dactylorhiza majalis, Gymnadenia conopsea, Orchis mascula, Orchis militaris and Orchis purpurea. The authors address those as varieties. It would be botanically more correct to name them as forms. There is also no taxonomic consistency – sometimes they are named var. albiflora, sometimes they are named var. alba. The hypochrome Ophrys forms of apifera and fuciflora are called var. flavescens, those of insectifera var. ochroleuca.

For me, it’s a bit odd that Dactylorhiza fuchsii is missing – those plants are subsumed among Dactylorhiza maculata agg. The authors are arguing that both taxa in Rhineland-Palatinate are “mixing”- while the populations in Saarland are following the “fuchsii type”. The book mostly shows photos shot in the Eifel region. There, the plants are tending to Dactylorhiza maculata with a distribution focus in Northwestern Europe. But further to the East, along the Rhine and in the Westerwald region there are also typical Dactylorhiza fuchsii.

The presentation of the book combined with a convention of AHO members was a good opportunity for professional discussions – here with Karel Kreutz (left) und Werner Hahn (right).

A witty lecture by the authors and photographers Jean Claessens und Jacques Kleinen was concluding the Day with a presentation of very detailled macro photos and the precise interaction of orchid flowers and pollinators.


Albiflora orchids in Romania

The diversity of the orchid flora in Romania is presented by Nora De Angelli and Dan Anghelescu in their book The Orchids of Romania. The richly illustrated book also shows 21 taxa with albiflora forms – mainly in the genera Anacamptis, Dactylorhiza and Orchis. Four white-flowered orchids are documented as special varieties: Dactylorhiza fuchsii var. albiflora, Dactylorhiza incarnata var. albiflora, Dactylorhiza maculata var. albiflora and Epipactis palustris var. albiflora. The book shows an abundant selection von photos, selected with love and passion, among them many with visiting or pollinating insects. In Romania there are 71 orchid species and 7 further newly detected species, the authors, father and daughter, are writing. Many of them are still well represented by numerous populations, though there are different dangers threatening their existence. We have a moral obligation to protect these wonderful yet extremely vulnerable plants, Nora De Angelli and Dan Anghelescu are stressing.

Nora De Angelli also sent me some photos of albiflora orchids in Romania to be presented here, which is really great. The first to be shown are those of Dactylorhiza maculata subsp. transsilvanica which are of special interest for the understanding of albiflora orchids between spontaneous mutations and the miracles of evolution.

Loss of pigment with Himantoglossum adriaticum

photo: Matthias Svojtka, 4.6.2014, in Vienna

Himantoglossum hircinum and Himantoglossum robertianum belong to the most common orchid species in southern Europe. In case of both species there are regularly plants with flowers lacking the Anthocyanine pigment. Those albiflora forms have green and white flowers instead of flowers with reddish stripes and points.

photo: Matthias Svojtka, 4.6.2014, in Vienna

Matthias Svojtka of the University of Vienna has also found an anthocyanine free form of the much rarer Adriatic lizard orchid (Himantoglossum adriaticum). “At this Himantoglossum location in the Lower Lobau there is a quite big population of about 40 to 60 plants in open grasslands, every year there are also one or two white-flowered plants“, he wrote about his photos.

photo: Matthias Svojtka, 4.6.2014, in Vienna

always beautiful: Gymnadenia conopsea f. albiflora

A region in the Steiermark, in the Austrian Alps, is the aim of a second hike in the mountains in Corona year 2020. On the Tauplitz-Alm I am mainly interested in the diversity of Nigritella species. Among the most common orchids of this mountain region is the fragrant orchid (Gymnadenia conopsea). Hundreds of them are flowering on meadows and forest clearings. Hiking to the Lawinenstein (1965 m) on July 7th I was surprised by a white-flowered Gymnadenia conopsea, with a long inflorescence. Gymnadenia conopsea is an orchid species which is developing white-flowered mutations quite regularly. But in most cases there are only singular plants of this form.

Albiflora abundance with Anacamptis palustris

In most regions of its distribution area Anacamptis palustris (synonyms: Orchis palustris, Paludorchis palustris) is highly endangered, because fens and wet meadows are more and more reduced. In a fen in the Bavarian district of Rosenheim there are still growing thousands of this special species.

On a meadow with about 100 flowering Anacamptis palustris there are also 7 albiflora forms – that’s a much higher percentage than what you could expect just by random genetic mutations. H. Kretzschmar, W. Eccarius and H. Dietrich (Die Orchideengattungen Orchis, Anacamptis, Neotinea. 2007) note: Rarely there are white-flowered plants showing a photo of an albiflora form from Lake Neusiedle in Austria. It seems that white flowered Anacamptis palustris are really rare, similar to its sister species Anacamptis laxiflora.

All flowers of the albiflora plants have not the slightest hue of purple. Even the pollinia are bright with a slight yellow influence, similar to the buds.

Anacamptis palustris in this fen is accompanied by smaller groups of Orchis majalis, Dactylorhiza incarnata subsp. ochroleuca, budding Epipactis palustris and Liparis loeselii.

Orchis pauciflora with reduced carotenoid pigments

Orchis pauciflora – photo: Bariša Ilić 

Among a population of about one thousand Orchis pauciflora in Southern Croatia, Bariša Ilić from Metković found 8 plants with almost white flowers. Their bright lips are contrasted with its reddish spots. This is the first time that he observed those special forms at a location near the town of Ston, in Dubrovnik-Neretva county. Bariša Ilić is an ornithologist, who fell in love with native orchids five years ago, as he explains.

Orchis pauciflora – photo: Bariša Ilić 

The flowers of Orchis pauciflora have a strong yellow color. They contain high concentrations of carotenoids – pigments who create the yellow flower color with many plants. While anthocyanines – which create red, purplish or brownish flower colors – are water soluble, carotenoids are lipid soluble (like chlorophyll). Since anthocyanines are produced in a complex process of biosynthesis with the participation of more than five enzymes, it is more likely that there will be a loss of anthocyanines than it might be in the case of carotenoids. This might explain why Orchis pauciflora with whitish instead of yellow flowers are extremely rare – and even in these findings, the plants seem to have retained a last rest of yellow color in the center of the labellum.

This impression of a gradual loss of carotenoid pigments corresponds with an interesting study of the Italian botanist Alessia Luca. She showed how the concentration of carotenoids is changing in the case of hybrids between Orchis pauciflora and Orchis mascula. Her thesis at the Università della Calabria includes the measuring of anthocyanin and carotenoid concentrations in the labellum of the hybrid plants, Orchis x colemanii. The results show that concentration von carotenoids is gradually decreasing in the hybrids: “O. xcolemanii showed a continuous flower color variation (Figure. 13) ranging from red-purple flowers of O. mascula to yellow flowers of O. pauciflora.” (Alessia Luca: Evolutive significance of hybridization in Mediterranean deceptive orchids, p. 42)

Alessia Luca: Evolutive significance of hybridization in Mediterranean deceptive orchids, p. 43

Comeback for the white Orchis militaris

In 2006, I first observed a white-flowered Orchis militaris in a grassland area near Frankfurt. It re-appeared in five following years. Last time I have seen it in 2010. But then it disappeared, no sign of an albiflora form among the more than 100 Orchis militaris plants of these meadows. Until this year, when it flowered again in a distance of about five meters from the first plant.

Orchis militaris f. albiflora

After the first third of May the inflorescence was already about to fade. The orchid expert Werner Hahn told me that in the 1980s the flowering in this habitat started only at about mid May – clearly a consequence of climate change in the last more than 30 years.

But the question remains: What is the reason that the albiflora form has a comeback after ten years? Seeds of the white-flowered plant might have been spread on this meadow. The color of flowers is a factor which is inherited by dominant alleles. But there still remains the small chance that the genetic characteristics of white flower will be expressed by the new plant in a population of more than 100 plants of the standard color.

Orchis militaris f. albiflora

The probability of albiflora forms among populations of Orchis militaris is about 1/1000, I guess. In the Middle Rhine Valley this beautiful plant is just flowering:

Orchis militaris f. albiflora – photo: Werner Hahn

Colony of Orchis quadripunctata f. albiflora

Orchis quadripunctata – photo: Robert Crnković

Orchis quadripunctata is a more than common species in mid Dalmatia. For more than ten years, Robert Crnković is looking for white, albiflora examples among numerous local populations  in the region of Trogir. In the beginning of May, he writes, I literately “stepped on” a small group of about 50 normal, pinkish plants, and, within the group, 14 snowy white ones. Such a great colony of albiflora forms can’t be explained by spontaneous mutations of individual plants. It seems that the white-flowered forms have propagated themselves in a quite unusual way.

Orchis quadripunctata – photo: Robert Crnković

In some cases of white-flowered Orchis albiflora the two or four small points on the base of the labellum – to which the name of the plant refers – retain the standard purplish color. Here the flowers are quite white.

Orchis quadripunctata f. albiflora – photo: Robert Crnković

Robert noted that all of these 14 plants have unspotted leaves – while the plants with purplish flowers have spotted leaves. This observation is conforming to the leaves of albiflora forms of other species like Dactylorhiza fuchsii which also lack the spots. The lack of Anthocyanine pigments affects not only the flowers but also the leaves.

Orchis quadripunctata f. albiflora – photo: Robert Crnković
Orchis quadripunctata f. albiflora – photo: Robert Crnković

Albiflora spring in Dalmatia

Himantoglossum robertianum – photo: Robert Crnković

Time and again, you can see the strong inflorescences of Himantoglossum robertianum in its hypochrome form. Jadranka Gubaš has now detected five of those plants at the coast near Šibenik, on a meadow with about 100 plants overall. Robert Crnković has taken the photos – thanks to both for this special greeting at the beginning of a new flowering season.

Himantoglossum robertianum
photo: Robert Crnković
Himantoglossum robertianum
photo: Robert Crnković