“The Coryanthes macrantha is perhaps the most wonderful of all known orchids, even more wonderful in structure and function than Catasetum.“
— Charles Darwin
Notes on the Fertilization of Orchids, 1869.
Orchids are well-adapted plants concerning evolution. However, they do not survive in water or desert sites. As to to fertilization, their flowers are among the most specialized. The great majority of orchids are pollinated by birds or insects and some of them are so specialized that they depend exclusively on a single species of insect.
Angraecum sesquipedale is known as Darwin’s orchid. Even though it had been discovered by a French botanist in the eighteenth century, it was Darwin who assumed that the flower was pollinated exclusively by a moth with a long enough snout (proboscis) to penetrate the 30 cm of the channel leading to the nectar receptacle. The scientist was mocked when he proposed this hypothesis which was proved to be true twenty years later.
When Darwin was a child, the beetles were perhaps the first life form that caught his attention. His famous collection had its beginning in Cambridge and some of his species can still be seen at the Cambridge Zoology Museum. On his voyage through Brazil, it took him just a day to collect several species of this group of insects.
In the preface to the second edition of Darwin’s publication on orchids, the naturalist thanks Fritz Müller for the new and curious information about the plant, as well as for the errors pointed out.
Müller, whom Darwin used to call the prince of observers, worked as a traveller naturalist for the National Museum in Brazil. The regular correspondence between Darwin and the German naturalist is rich in tropical species, examples of life-forms that are much more difficult to be studied in Europe, as the toucan, the bromeliads, and, mainly, the orchids. As Müller concentrated on the relation plant-insect, he also took part in the peculiar and specialized fertilization of the orchids.