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There are more “Darwin orchids” hidden in the remaining wilds of Madagascar. Missouri Botanical Garden scientists and collaborators discovered and described a new orchid species in Central Madagascar with a record-setting nectar spur and close ties to the famous Darwin’s orchid.

Urgent conservation action for the novel species, scientists say. 

“Discovering a new orchid species is always an exciting event, but finding such amazing and charismatic species happens only once in a scientist’s career.  I really hope that this highly threatened species draws attention to the urgent crisis that is affecting Madagascar’s biodiversity and helps support Garden’s program there,” said Tariq Stévart, Director of the Garden’s Africa and Madagascar program. 

Darwin’s Orchid

Angraecum sesquipedale, is known as Darwin’s orchid, to pay tribute to Charles Darwin’s theory that the flower was pollinated on a not-yet-discovered moth with a long proboscis. Scientists described the large hawkmoth  Xanthopan praedicta, 41 years after his prediction. 

This story of a unique plant and pollinator is one of the most celebrated predictions of the theory of evolution.

Meet Solenangis impraedicta

The flora of Madagascar is known for flowers with elongated floral tubes pollinated by long-tongued hawkmoths, like Darwin’s orchid.

A newly published paper, “A new orchid species expands Darwin’s predicted pollination guild in Madagascar,” reveals an unexpected new case of parallel evolution with Darwin’s orchid in the newly described giant spurred Solenangis impraedicta whose nectar tube reaches a whopping 33 cm in length.  

“The contrast between the little 2-cm flowers and the hyper-long nectar tube is mind-blowing” said coauthor JoãoFarminhão of the Coimbra University Botanic Garden.

Solenangis impraedicta has the third longest spur ever recorded amongst flowering plants, and the longest nectar spur of any known plant relative to flower size. It is the only new orchid species with such an extreme adaptation to hawkmoth pollination described since 1965.  

How scientist found the new species

Patrice Antilahimena, a Garden field botanist, first collected the species during the baseline environmental impact study of a mine site in Central-Eastern Madagascar. Ten years later, Garden Botanist Brigitte Ramandimbisoa and Simon Verlynde, Ph.D. student at the New York Botanical Garden, found the species again in a new location. The novelty belongs to the angraecoid orchids group that Stévart and an international team of experts have extensively studied. Stévart, an expert in African orchid taxonomy and conservation, first identified this orchid as an undescribed species of Solenangis. 

Conservation Concerns

Mining activity and potential poaching for the orchid trade threaten this sensational new member of “Darwin’s pollination guild.

“A precautionary approach is required when publishing such a spectacular new species. Wild populations must be protected and monitored and detailed information on their precise coordinates must be kept out of the public domain. So, don’t ask us to reveal where we found it, somewhere in Madagascar,” added Stévart.  

The 15-year gap between this species’ discovery and formal description allowed the team to implement conservation measures before the giant-spurred Solenangis achieves stardom. These include ex situ cultivation and seed banking as part of a collaboration between the Garden and the Ambatovy Conservation Department.

Ex situ conservation is the process of protecting an endangered species outside of its natural habitat.

More to learn 

The pollination biology of Solenangis impraedicta was preliminarily studied using camera traps by Marie Savignac in 2019. The observational period did not result in any conclusive pollination events. However, the most likely pollinators are the large hawkmoths, Coelonia solani and Xanthopan praedicta. The species name impraedicta, meaning unpredicted in Latin, is a nod to Darwin’s prediction of the star orchid pollinator, which took 130 years to confirm in full. Hopefully, this time it won’t take as long to identify the pollinator in the act.