Scientists with the Missouri Botanical Garden and collaborators have stumbled upon a remarkable new orchid species in Central Madagascar. This orchid, boasting a record-setting nectar spur, is a close relative of the famed “Darwin's orchid” and necessitates immediate conservation efforts.
“Unearthing a new orchid species is always thrilling, but encountering something as extraordinary and captivating as this happens rarely in a scientist's lifetime,” remarked Tariq Stévart, Director of the Garden's Africa and Madagascar program. “My fervent hope is that this critically endangered species will garner much-needed attention to the dire situation Madagascar's biodiversity faces, and bolster the Garden's ongoing conservation efforts in the region.”
Madagascar's unique flora is renowned for its flowers featuring elongated nectar tubes specifically adapted for pollination by long-tongued hawkmoths. The most celebrated example is Angraecum sesquipedale, also known as Darwin's orchid. Named in honor of Charles Darwin's prediction, this orchid was theorized to be pollinated by a moth with an exceptionally long proboscis, which scientists remarkably identified 41 years later – the giant hawkmoth, Xanthopan praedicta.
A recently published research paper titled “A new orchid species expands Darwin's predicted pollination guild in Madagascar” unveils a new instance of parallel evolution with Darwin's orchid. The newly described species, Solenangis impraedicta, boasts a giant nectar spur measuring a staggering 33 cm – the third longest among all flowering plants and the longest relative to flower size.
“The stark contrast between the tiny 2-cm flowers and the extraordinarily long nectar tube is simply mind-boggling,” stated co-author João Farminhão from the Coimbra University Botanic Garden.
Solenangis impraedicta holds the distinction of being the sole new orchid species documented since 1965 with such an extreme adaptation for hawkmoth pollination.
The initial discovery of this remarkable orchid is credited to Patrice Antilahimena, a field botanist with the Missouri Botanical Garden, during a baseline environmental impact assessment at a mine site in central-eastern Madagascar. A decade later, Garden Botanist Brigitte Ramandimbisoa and Ph.D. student Simon Verlynde from the New York Botanical Garden located a new population.
This fascinating addition to “Darwin's pollination guild” faces significant threats from mining activities and potential poaching for the orchid trade.
“Publishing information on such a spectacular new species necessitates a cautious approach. Protecting and monitoring wild populations are paramount, and precise location details must be withheld from the public domain. Therefore, please refrain from inquiring about the exact location – suffice it to say, somewhere in Madagascar,” emphasized Stévart.
The 15-year gap between discovery and official description allowed the research team to initiate crucial conservation measures before Solenangis impraedicta gains widespread recognition. These efforts include ex situ cultivation (growing the orchid outside its natural habitat) and seed banking, undertaken collaboratively by the Missouri Botanical Garden and the Ambatovy Conservation Department.
Preliminary studies on the pollination biology of Solenangis impraedicta were conducted in 2019 using camera traps by Marie Savignac. While conclusive evidence of pollination events wasn't obtained, the most likely pollinators are believed to be the large hawkmoths Coelonia solani and Xanthopan praedicta. The name “impraedicta” (meaning “unpredicted” in Latin) serves as a subtle nod to Darwin's prediction concerning the pollinator of the star orchid, which took over a century to fully validate. Researchers hope the identification of the pollinator for this new species won't require such an extended timeframe.
The study is published in the journal Current Biology.