For most, the Azores are known for an event in 2003, when United States President George W. Bush, British Prime Minister Tony Blair, Spanish Prime Minister José María Aznar and the Portuguese Prime Minister José Manuel Durão Barroso held a summit there days before the commencement of the Iraq War. For certain scientists, the archipelago is interesting for an entirely: Orchids. Namely, how many species? One, maybe even two?

Neither. The answer is three. Hochstetter’s Butterfly-orchid, newly recognized following application of a battery of scientific techniques, is arguably Europe’s rarest orchid species. Under threat in its mountain-top retreat, the orchid urgently requires conservation recognition. A publication, titled “Systematic revision of Platanthera in the Azorean archipelago: not one but three species, including arguably Europe’s rarest orchid”, was published today in the peer-reviewed open-access journal PeerJ.

The research team, led by independent botanist Prof. Richard Bateman in collaboration with local botanist Dr. Mónica Moura (University of the Azores) and plant morphologist Dr. Paula Rudall (of the Royal Botanic Gardens Kew), originally viewed butterfly-orchids as a simple, tractable system ideal for studying the origin of species and so they initiated a focused exploration of all nine Azorean islands.

Until now, field and laboratory research found it easy to distinguish the widespread Short-spurred Butterfly-orchid (Platanthera pollostantha) from the rarer Narrow-lipped Butterfly-orchid (P. micrantha) using morphology, DNA sequences, and the identities of mycorrhizal fungi associated with the roots of the orchids. As it happened, things became decidedly less “simple” when Dr. Moura explored remote dwarfed laurisilva forests along the highest volcanic ridge on the central island of São Jorge and found an unusual population of butterfly orchids.

“I immediately recognised the flowers as being exceptionally large for an Azorean butterfly-orchid,” said Moura, “and e-mailed images to Richard Bateman for confirmation that they were new to science.”

Subsequent data all pointed to the discovery of a new species, which likely originated relatively recently by a remarkable restoration of the large-flowered morphology of its presumed mainland ancestor.

Even more unbelievable, Bateman soon realized that while the species might be new to science, it was actually discovered nearly 175 years ago, and illustrated in the first ever Flora of the islands in 1844. After that, it had been confused with the other, more common Azorean orchid species. The illustrated specimen, deposited in the herbarium at Tübingen by German botanist Karl Hochstetter, was collected during his tour of six of the nine Azorean islands in 1838.

“This remarkable species languished unrecognized for 173 years,” commented Bateman. “It’s rediscovery and recognition beautifully illustrate the value of integrating field-based and laboratory-based approaches to generate a modern monograph. This methodology both demonstrates that the species is genuine and allows us to make informed recommendations for its future conservation.”