Tuesday 13 November 2018

Raphia gabonica & Raphia zamiana: Two new species of Palms from Gabon and Cameroon.

Palms are an important component of modern tropical ecosystems, with the majority of species (~90%) restricted to tropical rainforests, where they are important understory plants. Palms reach their maximum diversity today in Asia (over 1200 species) and the Americas (about 730 species), but are much less diverse in Africa (about 65 species, less than Madagascar, which has about 200), with only one species native to Europe. Despite Palm Tree being the most familiar form of Palms, there are also climbing, shrubby, and stemless forms. The genus Raphia contains about 20 species of economically significant Palms, noted for their fibrous leaves (the largest leaves of any known Plant) used in making thatch, furniture and matting, and edible fruit. Almost all species of Raffia are found in Africa, with one species found in Central and South America, and one in Madagascar. Despite their economic significance, Raphia Palms have been little studied by botanists, largely due to their preference for swampy tropical environments.

In a paper published in the journal PhytoKeys on 6 November 2018, Suzanne Mogue Kamga of the Plant Systematic and Ecology Laboratory at the University of Yaoundé, Raoul Niangadouma of the National Herbarium of Gabon, Fred Stauffer of the Conservatoire et Jardin botaniques de la Ville de Genève and the Laboratoire de systématique végétale et biodiversité at the Université de Genève, Bonaventure Sonké, also of the Plant Systematic and Ecology Laboratory at the University of Yaoundé, and Thomas Couvreur of the Université de Montpellier and the Naturalis Biodiversity Centre, describe two new species of Raphia from Gabon and Cameroon.

The first new species described is named Raphia  gabonica, in reference to the country Gabon where it was discovered. The Palm forms a tree with a trunk 3-7 m in height and 20-30 cm in diameter, surmounted by 7-8 leaves, 8-13 m in length. Old leaf sheaths persist and hang down around the trunk, protecting and largely obscuring it. Flowers and fruit are born on pendulous rachillae up to 1.8 m in length. This Palm was found at only two locations, on hill slopes near streams in lowland rainforest in northern Ngounié Province, in Gabon, with a total known area occupied of less than 8 km². For this reason the species is considered to be Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species

 Raphia gabonica in natural habitat (Alèmbé, Gabon). Notice dry land habitat, not growing in colonies, single stem with curly fibres and long pendulous inflorescences. Thomas Couvreur in Mogue Kamga et al. (2018).

The second new species described is named Raphia zamiana, where 'zamiana' derives from 'Zam' the name for these Palms in Beti, a language spoken in southern Cameroon and northern Gabon. This Palm forms trees with trunks 3-8 m high and 30-40 cm in diameter, surmounted by 10-12 leaves, 12-21 m in length. Again old leaf sheaths persist and hang down around the trunk, protecting and largely obscuring it. Flowers and fruit are born on pendulous rachillae up to 2.8 m in length. This Palm is found in the Atlantic rainforests of central and southern Cameroon, Gabon and probably Equatorial Guinea. The species is extremely abundant and widely used by local populations for its leaves which are used as a construction material, as thatch, and to make furniture, baskets and mats. Its fruit are also harvested and sold as a treatment for hypertension and diabetes. The sap of this species is collected for Palm wine, and edible Grubs are collected from it.

Raphia zamiana. Habitat along the road, with Raoul Niangadouma for scale (Oyem, Gabon). Thomas Couvreur in Mogue Kamga et al. (2018).

See also...

https://sciencythoughts.blogspot.com/2017/01/endothermy-in-ivory-palms.htmlhttp://sciencythoughts.blogspot.co.uk/2015/05/pathogenic-oomycete-chromists-from-new.html
http://sciencythoughts.blogspot.co.uk/2014/11/fossil-coryphoid-palm-leaves-from.htmlhttp://sciencythoughts.blogspot.co.uk/2014/11/the-impact-of-yellow-crazy-ant-on.html
http://sciencythoughts.blogspot.co.uk/2014/10/the-conservation-status-of-madagascan.htmlhttp://sciencythoughts.blogspot.co.uk/2013/06/three-new-species-of-palm-weevil-from.html
Follow Sciency Thoughts on Facebook.