A remarkable new palm from Madagascar

As a result of its long isolation, Madagascar has unique biota. Although it is best known for its lemurs, Madagascar’s palm flora is both diverse and distinctive. In 1995 Dransfield and Beentje recognised 170 species of palms from Madagascar, 164 of which were found only in Madagascar. Since then another 7 species have been described, with another 20 apparently awaiting description. Most of these new species have been found in the eastern wet areas. The western part of the island is drier, and has a much less diverse palm flora. However, an entirely new genus has been discovered in the western dry region – one that is so large and distinctive that the BBC reports it can be seen in satellite images. A description of this new species, Tahina spectabilis was published in the January issue of the Botanical Journal of the Linnean Society.

Tahina, which means “blessed” or “to be protected” in Malagasy (and is also the name of the daughter of the Metz family, Anne-Tahina), is a remarkable tree. It is one of the largest palms in Madagascar, growing 10 m tall (20 m according to the BBC article) with stem diameter of 50 cm. It is also hapaxanthic – it reproduces just once in its lifetime and then dies. As a result of this, it puts all of its resources into flowering, producing a 4-m tall inflorescence. (You can see an image of it here.)

In August 2005 the Metz family first observed the species on a family picnic, but since it was not flowering, they assumed that it was a Borassus. However, when they returned in 2006 they saw the tree in flower. Their pictures were posted on the PalmTalk bulletin board by Bruno Leroy on December 5, 2006, where its similarity to the Asian genus Corypha was noted. One of the regulars on the board contacted John Dransfield of Kew Gardens, who determined that the species was not a Borassus, and thought that it was unlikely to be a Corypha, since the area appeared to be too remote for one to have been planted there. Images of the crown were also inconsistent with Corypha. Corypha (the Talipot Palm) has a similarly massive terminal inflorescences (picture, on right) and has been planted around the world. I have seen them in flower in Trinidad and Puerto Rico, and one of them in flower is a truly remarkable sight.

In January 2007 Mijoro Rakotoarinivo, Bruno Leroy and the Metz family visited the site and made the first botanical collections of the species. The species was determined to be an unknown member of the tribe Chuniophoeniceae which comprised of three genera: Nannorrhops, which is found from Arabia to Afghanistan, and Pakistan; Kerriodoxa which is found in southern Thailand; and Chuniophoenix which is found in Vietnam and southern China. Unlike Tahina, these genera are slender or moderate sized palms. In addition to being physically distinctive, Tahina is also geographically disjunct from its closest relatives.

Apart from everything else about this tree, I especially like the internet aspect. Certain taxa, like palms and fish, support dedicated communities of enthusiasts. Their interest can not only lead to new discoveries, it can also be harnessed into research and conservation efforts. And, remarkably, they generate groups of non-scientists who actively read taxonomic monographs. And to me, that’s just awfully cool.

Dransfield, J., Rakotoarinivo, M., Baker, W.J., Bayton, R.P., Fisher, J.B., Horn, J.W., Leroy, B., Metz, X. (2008). A new Coryphoid palm genus from Madagascar . Botanical Journal of the Linnean Society, 156(1), 79-91. DOI: 10.1111/j.1095-8339.2007.00742.x

Dransfield J, Beentje HJ. 1995. The Palms of Madagascar. Royal Botanic Gardens Kew and International Palm Society, HMSO Norwich.