Nigritella – albiflora

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.

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.

Colour plays with Nigritella rhellicani

In July, the dark red heads of Nigritella rhellicani (syn: Nigritella nigra ssp. rhellicani) are covering many alpine meadows. In some rare places, the flowers show remarkable colour variatation. After studying the Nigritella hues of the Dolomite Alps, this year I visited the Swiss canton Valais: Near Chandolin there is a place in an altitude of about 2400 m with pink and yellow flowering Nigritella rhellicani. The tableau above shows the colour varieties in both the Dolomites and Switzerland. The yellow flowering forms grow near Chandolin – they obviously miss the anthocyanins, but have other pigments as probably carotenoids. The reasons for this special forms are unknown up to now.

Nigritella bicolor – a new, but well known species

A new species description offers the chance to clarify open questions while studying the alpine Nigritella flora: In the latest edition of the Journal of European Orchids (1/2010), Wolfram Foelsche describes a broad spectrum of doubtful cases where Nigritella plants have been identified as Nigritella rubra without showing the characteristics of this plant as it was described by Richard Wettstein in 1889. With Nigritella rubra sepals and petals should have about the same width. But many plants identified as Nigritella rubra have petals which are considerably slimmer than the sepals. Additionally there are also differences regarding the form of the lip and the colour of the inflorescence: In most cases the plant now described as Nigritella bicolor shows a brighter red in the lower part of the inflorescence than in its upper part. And Nigritella bicolor has a longer spur than Nigritella rubra.

“With its striking inflorescence – above a rim with brightly shining rays the rows of rose-coloured flowers are displayed while the tips of bracts are set apart in dark-red – this new species, without doubt, is our splendid, most attractive nigritella”, Foelsche writes. According to his studies the majority of the photos used to illustrate Nigritella rubra are actually showing Nigritella bicolor which has a much larger area of distribution. Foelsche notes that the bicolour characteristics may be more or less strongly developed. It’s not possible to confound Nigritella bicolor with colour varieties of Nigritella rhellicani with its open labellum:

Exhibition in Frankfurt demonstrates color in nature

“The palette of colors in nature is almost infinite”, says the botanist Hilke Steinecke of the Palmengarten in Frankfurt. There, this palette is displayed in an exhibition which can be visited until November 1st. The exhibition also explains the role of pigments in the colors of flowers and how fertilizing insects see colors.

An interesting demonstration shows the acid sensitivity of anthocyanins. When a drip of vinegar is placed on the violet flower of Ipomoea, its color changes to pink. “In an acid milieu many anthocyanins are rose-pink, in an alkaline milieu blue”, as it is stated in the catalogue. This phenomenon could also explain the color variations of Nigritella nigra ssp. rhellicani in the Dolomite Alps – these occur especially in a region with rather acid soil.

Nigritella hues of the Dolomite Alps

The Puflatsch Alm above the alpine village Siusi is famous for its colour varietes of Nigritella nigra ssp. rhellicani. As part of a field trip in the Dolomite Alps I had the chance to explore this region with an altitude of 1990 to 2150 metres for four days. Especially rich is the flora in the surroundings of the Arnica Huette, where thousands of Nigritella and Gymnadenia conopsea are flowering in mid July. Additional orchid species are Pseudorchis albida and – in depressed areas – Dactylorhiza majalis.

Among the flowering Nigritella colour varietes are quite common, even though I couldn’t find a totally white one. All the pale-yellow or white flowering plants still had single flowers with a slight rose hue on the edges of the lip. The most common colour variety is an inflorescence with light red flowers in the upper and pale flowers in the lower part.

Not rare at all are hybrids of Nigritella nigra ssp. rhellicani with Gymnadenia conopsea. Their carmine flowers are glowing in the meadows. Interesting was a hybrid of a colour variety of Nigritella nigra ssp. rhellicani with Gymnadenia conopsea, resulting in an inflorescence (left) much lighter than with common hybrids of both species (right):

Gymnadenia conopsea x Nigritella nigra ssp. rhellicani

Overview on all the orchid genera

The shipment took more than a month but now the book has arrived from Cornell University Press in Ithaca, New York. It’s really intersting, the Illustrated Dictionary of Orchid Genera. The authors Peggy Alrich and Wesley Higgins present an overview on all the genera of the family of orchids – from Aa to Zygostates.

Aa is quite a nice story – this valid taxon was defined by Heinrich Gustav Reichenbach in 1854. One explanation for the unusual name is that Reiuchenbach took the first and the last letter of the related genus Altensteinia in order to be always at the first place of the compendia – the new reference book demonstrates his success. Another explanation says that Aa with its 27 species in Central and Southern America commemorates the Dutch printer Pieter van der Aa.

The preface states that there are about 850 accepted genera in the world of orchids – but the number described in the book is more than three times greater. The two authors have introduced a colour scheme to present them: A vivid green stands for the validly published and “currently accepted” names of genera. Light green is the colour of the validly published but “not currently accepted” taxons – among them are e.g. Listera (now: Neottia) or Aceras (now Orchis). The deprecation is explained with molecular-genetic studies: “Current DNA testing of this genus shows that Aceras is clearly nested within Orchis.” With the same reason Nigritella is put to Gymnadenia – but Barlia is printed in vivid green as an accepted taxon, though Barlia robertiana was classified as belonging to Himantoglossum by molecular biologists.

The compendium explains classification and etymology for each genus listed, followed by a synopsis of the genus with the number of species, geographic distribution, favoured habitat and a short description of morphological features. For each genus there is an illustration of a flower. In the global context the European genera of orchids appear in a a rather limited scope. The authors state that they expect the discovery of new species but these may find their place in the now existing structure of genera.