Why are there no epiphytic orchids in Europe?
Yesterday when leaving the Thai temple in Jämtland, Sweden, Eric took a turn and said ‘let’s look out for orchids’. Almost immediately he shouted and hit the brakes. He stepped out and shouted again: another species: Dactylorhiza maculata s.lat. ¨Here is another one: Dactylorhiza viridis¨. He ran back to the orchids he saw first, and stopped again: Gymnadenia conopsea! The first orchid was a stand of large white Platanthera bifolia, highly fragrant. All four orchid species are terrestrial, and so it was quite interesting to see my first European orchids, although quite small.
I asked why there are no epiphytic orchids anywhere in Europe? The answer is not evident. Temperature is not the only answer, as the peak of Doi Inthanon in Thailand may have frost, and southern Europe is quite hot. Although orchid biology is complicated including special pollinators and their host plants, one could imagine that small seeds would transport far like fungal spores and establish, although not reproduce. It seems each orchid species is highly adapted to its niche, so for germination very special requirements are needed. To move an orchid, pollinator and its host plant out of the area is tricky. However, there are many terrestrial orchids in Europe, so there is something with the epiphytic orchid life form that does not suit Europe. We do have mistletoe (Viscum album), so plants can apparently adapt to freezing temperatures up in trees. If anyone has any clever thoughts, please share with us.
Swedish Platanthera bifolia (Orchidaceae) is highly fragrant and most charming!