Europe’s rarest species of orchid has been rediscovered on a single volcanic ridge in the Azores, claim scientists.The new species, known as Hochstetter’s butterfly-orchid, was first found in 1838 but had escaped official recognition for almost two centuries. Researchers analysed the islands’ orchid populations and found the archipelago had three species of butterfly-orchid. The findings are published in the open-access journal PeerJ. Orchids are one of the most diverse and widespread families of flowering plants, with Europe home to more than 300 species. And according to the research team, the Azores are an ideal place to study the evolution of orchid species as the archipelago is located 1600km (990 miles) from the nearest landmass of Portugal. “Like many evolutionary biologists before me, I decided that an island system would be much simpler and would therefore yield less ambiguous results,” explained lead researcher Professor Richard Bateman from the Royal Botanic Gardens Kew. The team took samples for microscopy and DNA analysis and made detailed floral measurements of hundreds of plants from populations of butterfly-orchids spread across nine islands. Prof Bateman predicted they would find two readily distinguishable species. They found two species: the widespread short-spurred butterfly-orchid was present on all the islands and the rarer narrow-lipped on eight of the islands. However the team made a surprising discovery when they surveyed a population on the top of a volcanic ridge on the central island of Sao Jorge. “[I] was astonished when our field expeditions revealed the existence of a third – and exceptionally rare – species, growing in such a dramatic, primeval landscape. “I was even more astonished when my subsequent studies in herbaria and libraries showed that this exceptionally rare orchid, found only on one mountain-top on a single Azorean island, had in fact been found by the very first serious botanist to visit the Azores, in 1838,” Prof Bateman told BBC Nature. According to the team, it proved easier than expected to identify that the origin of the Azorean orchids was Europe rather than North America but surprisingly difficult to identify which part of Europe they came from, or how recently the westward journey took place. Prof Bateman explained that because European orchids are so charismatic and biologically interesting, they have been the subjects of a great deal of scientific research by both professional and amateur researchers. “The Azores make a refreshing change in that too few orchid species have been recognised on the islands,” he said. “It is a welcome bonus that the overlooked species has proven to be so informative about how evolution takes place… offering a suitable focal point for advocating conservation. “[It is also] becoming my preferred contender for the title of Europe’s rarest orchid species,” Prof Bateman told BBC Nature. By Jeremy Coles – BBC Environment
