During the next few weeks, people who visit the Parque Botánico-Orquidario in Estepona can enjoy seeing how many species are in flower at this time of year. One stands out especially among the rest, because it is difficult to find in private collections anywhere in the world and also because of its close association with one of the most influential people of the 19th century and human history, British scientist Charles Darwin, the father of the theory of evolution.
The species in question is the Angraecum sesquipedale, also known as the Christmas orchid, Star of Bethlehem orchid or just Darwin's orchid. It is special because, among the more than 25,000 varieties that exist, it is the orchid with the longest spur, the cavity from which insects extract the pollen, measuring between 20 and 25 centimetres.
Orchids were of special interest to Darwin. Their immense variety, shapes and colours posed interesting challenges when it came to studying their methods of reproduction, to such an extent that he published a book just about their fertilisation. It tells how Darwin received a package of several orchids from British horticulturist James Bateman, which included the Angraecum sesquipedale. He was struck by the length of the spur and, following the premises of his evolutionary studies based on changes in species due to natural selection, he believed that there must be a pollinating insect in existence with a proboscis long enough to reach the nectar receptacle at the end of the spur.
In other words, Darwin suggested that the Angraecum and its supposed pollinator had acquired their striking physionomy through a process of evolution in which one species responded to changes in the other. Nowadays, this is known as co-evolution, or sometimes as concerted evolution.
At first, this idea was greeted with incredulity by his scientific colleagues, because no insect of that type had ever been seen. However, over time Darwin was proved right: forty years later, in 1903, in Madagascar, which is where this species of orchid originated, a type of moth appeared with a proboscis measuring nearly 30 centimetres.
This confirmed Darwin's belief, and the insect was given the name Xanthopan morganii praedicta, whose subspecific epithet alludes precisely to Darwin's prediction about the existence of this hawk moth.
Darwin's orchid can be still be seen in flower for the next two months at the Parque Botánico-Orquidario de Estepona, which has successfully adapted to the conditions it needs to survive. This was no easy task because it is a capricious species and it has taken several attempts and different locations in the park before the plant decided it was happy to grow there.
Something else unusual about this plant is that it emits its strong scent at night. One of the experts at the orchid park, Anatoli Minzatu, says it can be smelled from at least five metres away, so it is a pity that this type of natural museum can only be visited during the day.
Anatoli has been working at the botanical park since shortly after it opened, nearly six years ago. During that time he has seen it evolve and grow.
"We have nearly 1,500 species of orchid here now. There are apparently between 25,000 and 35,000 different varieties, and new ones are still being discovered. Some countries, such as Ecuador, have more than 4,500 different types, and in different parts of Asia new ones are found every year," he says.
The countries in South America are the main orchid exporters. Each species which arrives at the orchid park in Estepona has to be carefully studied and they all need special care.
"Many of them need a period of up to two or three years just to adapt to their new environment," says Anatoli.
He says the aim of the park is to have as many as 8,000 different varieties on display within the next few years, and if it is successful in achieving this it would become one of the most important parks of this type in the world.