Madagascan suicide palm

The Essence

"Tahina spectabilis is a solitary fan palm endemic to north-western Madagascar, described as new to science only in 2008 after Xavier Metz, the manager of the VERAMA cashew plantation, and his family came across it near the village of Antanamarina in late 2006. Photographs posted online in early December 2006 reached Kew and John Dransfield, then Kew's Head of Palm Research, within 24 hours; Mijoro Rakotoarinivo visited the site in January 2007 to take measurements and collect herbarium specimens, and the new genus and species were published in time to be added to the manuscript of the second edition of Genera Palmarum just before it went to the printers. Morphological, anatomical and molecular evidence placed the palm in the tribe Chuniophoeniceae, whose only other members are Nannorrhops in Arabia, Iran, Afghanistan and Pakistan, Kerriodoxa in southern Thailand and Chuniophoenix in Vietnam, southern China and Hainan - an extraordinary biogeographic disjunction, and a genus genetically distant from every other Madagascan palm. It is hapaxanthic: it flowers once, in a single enormous terminal inflorescence, and then dies, which earned it the media nickname "the Madagascan suicide palm". Demographic modelling estimates that it takes approximately 73 years, give or take 24, for a tree to reproduce. It is the largest palm species from Madagascar, with a crown big enough for individual plants to be picked out on satellite imagery. The 2007 fruiting was turned into a conservation programme. Kew's Millennium Seed Bank and the Silo National des Graines Forestieres worked with VERAMA and the Antanamarina community to sell the seed internationally, and the proceeds paid for a new school and a pump for the village well, plus annual maintenance of a firebreak around the tsingy outcrop and fences to keep zebu from trampling young plants. A second population was found during a September 2016 expedition, further inland and just 10 km from Route National 6: 25 individuals including five adults, the largest a medium-sized adult about 12 m tall. Even so, the number of mature individuals known in the wild remained only 34. The same expedition re-censused the original site at Antsingilava and recorded 568 individuals, 27 of them trunked adults, plus 170 seedlings about 1.5 km away at Ambatosaromby; Kew put the total known population on the peninsula at 740 plants. Much remains unknown. Pollination and dispersal are not established - the many thousands of small flowers attract large numbers of insects, recorded as a personal observation by Xavier Metz, and lemurs, bats or parrots have been suggested as possible dispersers because they occur in the area. The original population is genetically depauperate, and all ex-situ material derives from that single 2007 flowering event and so carries low genetic diversity; the newly discovered populations hold more. It was chosen as one of the top ten species discoveries of 2008 by the International Institute for Species Exploration."

The palm was found in late 2006 on a remote north-western peninsula by Xavier Metz, the manager of a cashew plantation, and his family; returning a year later, they found that one of the trunked individuals was flowering. Photographs posted online reached Kew within 24 hours, fieldwork followed in January 2007, and the new genus and species were published in 2008, in time to be added to the second edition of Genera Palmarum before it went to the printers. High germination rates from the 2007 seed collection, together with exchange of seed and seedlings between Kew and other botanic gardens, are why the species is now grown in many public and private gardens around the world.