This 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.

At 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.

Following the hint of an orchid friend, today I’m travelling to the Hesse part of the mountain region Rhoen. Northeast of Fulda, near Huenfeld, a path is leading through a long stretch of forest. Along a slope there are flowering countless Cephalanthera rubra. And directly at the path there are three plants with white flowers. Die first still has a slight violett hue. The second is totally white, but already slightly withering, and the third has only one, relative closed flower.

Along the slope there are more than one hundred Cephalanthera rubra, Gymnadenia conopsea and Epipactis atrorubens. There is one Gymnadenia conopsea flowering almost white, with a last hue of violett in the flowers.

South of Fulda and west of Bad Brueckenau we follow another hint and find a hilltop with an impressive  grassland vegetation. In the lower range there are numerous Gymnadenia conopsea. Farther above, some meters from the forest, there are Epipactis atrorubens flowering -- and among them some plants, which are not flowering red-brown, but yellowish-green! While strolling this wonderful slope, I’m seeing a white flowering Gymnadenia conopsea var. albiflora! It is a strong plant with more than 30 flowers, the upper ones still as buds. On the hill there are many butterflies and wild bees. The white flowering Gymnadenia is offering them with its spur filled with nectar as an interesting alternative.

Weiß blühende Orchideen mit einer anderen Standardfarbe werden oft als “Albino”-Form bezeichnet. Tatsächlich aber können Albino-Pflanzen, denen das für die Photosynthese unerlässliche grüne Pigment Chlorophyll fehlt, durchaus farbige Blüten haben, wie diese Aufnahme einer Cephalanthera rubra aus Thüringen von Holger Disse zeigt.

Umgekehrt haben die meisten Albiflora-Orchideen zwar weiße Blüten, aber durchaus kräftig grüne Blätter und auch einen solchen Stängel. Ihnen fehlen die für die Blütenfarbe relevanten Pigmente aus den Gruppen der Carotenoide und Anthocyanine. Sie verfügen aber über reichlich Chlorophyll, erhalten also auch Nährstoffe aus der Photosynthese.

Bei manchen Orchideen ist die Ausbildung der Blütenfarbstoffe reduziert, Anthocyanine werden aber noch in geringem Ausmaß gebildet, wie es bei der hier gezeigten Cephalanthera rubra der Fall ist. Diese weiß blühenden Pflanzen mit einem Hauch von Standardfarbe könnten als Teil-Albiflora-Form bezeichnet werden.