RESUMO
Raphia (Arecaceae, Calamoideae) is the most diverse genus of African palms with around 20 species. Two new species from Cameroon and Gabon, Raphiagabonica Mogue, Sonké & Couvreur, sp. nov. and Raphiazamiana Mogue, Sonké & Couvreur, sp. nov. are described and illustrated. Their affinities are discussed and the conservation status of each species is assessed. For both species, distribution maps are provided. Raphiagabonica is restricted to two small populations from central Gabon, where it occurs on hillsides on tierra firme soil, and close to small streams. Its preliminary IUCN status is Endangered, being amongst the five most threatened palm species in Africa. Raphiagabonica potentially belongs to the moniliform section. Raphiazamiana is largely distributed from south Cameroon to south Gabon and is very common. It is also a multi-used palm, from which wine, grubs and construction material are extracted and sold. It generally occurs in large stands in a wide range of ecosystems such as swamps, coastal forests on partially inundated sandy soils and inundated savannahs. Its large stature, hard to access habitat (swamps) and abundant presence might have discouraged botanists to collect it until now. Raphiazamiana belongs to the taxonomically complex raphiate section.
RESUMO
Monts de Cristal National Park in northwest Gabon is one of the most species rich places in Central Africa. Here, we describe two new species, one in Annonaceae and one in palms. Uvariopsis citrata Couvreur & Niangadouma, sp. nov. is unique in the genus by emitting a strong lemon scent from the crushed leaves and young branches. Laccosperma cristalensis Couvreur & Niangadouma, sp. nov. is a rattan that lacks acanthophylls on the cirrus and has few pinnae. Complete descriptions, photographic illustrations, ecological information and preliminary IUCN conservation status are provided. For both species a data deficient (DD) status is proposed. These new species underline once again that the Monts de Cristal National Park is yet incompletely known botanically.
RESUMO
BACKGROUND: Gabon is an important center of biodiversity in Central Africa. The country contains to date 27 species of palms. However, palms are generally poorly collected as these massive plants are hard to press and curate. Thus, our understanding remains incomplete, especially in Central Africa. NEW INFORMATION: We report three new records of two palm species for Gabon: Sclerosperma profizianum Valk. & Sunder. and Eremospatha quiquecostulata Becc.. The former species was collected in southeast Gabon, near Ndindi, while the later was collected in the Massif du Chaillu and Monts de Cristal National Park (Crystal Mountains National Park). The total number of palm species for Gabon is now 29, making it an important centre of palm diversity in Central Africa.
RESUMO
A distinctive new monotypic genus from Gabon is described in the tropical plant family Annonaceae: Sirdavidia, in honor to Sir David Attenborough. Molecular phylogenetic analyses confirm that Sirdavidia, which is very distinct from a morphological standpoint, is not nested in any existing genus of Annonaceae and belongs to tribe Piptostigmateae (subfamily Malmeoideae), which now contains a total of six genera. The genus is characterized by long acuminate leaves, fully reflexed red petals, 16-19 bright yellow, loosely arranged stamens forming a cone, and a single carpel topped by a conspicuous stigma. With just three known collections, a preliminary IUCN conservation status assessment is provided as "endangered" as well as a distribution map. The discovery of Sirdavidia is remarkable at several levels. First, it was collected near the road in one of the botanically best-known regions of Gabon: Monts de Cristal National Park. Second, its sister group is the genus Mwasumbia, also monotypic, endemic to a small area in a forest in Tanzania, some 3000 km away. Finally, the floral morphology is highly suggestive of a buzz pollination syndrome. If confirmed, this would be the first documentation of such a pollination syndrome in Magnoliidae and early-diverging angiosperms in general.
RésuméUn nouveau genre monotypique du Gabon est décrit dans la famille tropicale des Annonaceae: Sirdavidia, en honneur à Sir David Attenborough. Des analyses phylogénétiques confirment que Sirdavidia, caractérisé par une morphologie unique, n'appartient à aucun genre connu d'Annonaceae et se place au sein de la tribu des Piptostigmateae (dans la sous-famille des Malmeoideae), laquelle compte désormais un total de six genres. Le genre est caractérisé par des feuilles avec un long acumen, des pétales rouges réfléchis, 1619 étamines jaunes qui forment un cône lâche et un carpelle surmonté d'un stigmate bien visible. Avec seulement trois récoltes connues, un statut de conservation préliminaire de "endangered" est proposé sur la base des critères de l'UICN. Une carte de distribution est également fournie. La découverte de Sirdavidia est remarquable pour plusieurs raisons. Tout d'abord le nouveau genre a été collecté près de la route dans l'une des régions les plus connues botaniquement du Gabon: le Parc National des Monts de Cristal. Ensuite, son groupe-frère est le genre, Mwasumbia, également monotypique, endémique d'une petite région en Tanzanie à plus de 3000 km. Enfin, les caractères floraux suggèrent un syndrome de pollinisation appélé « buzz pollination¼. Si cela se confirme, ce sera la première documentation de ce type de syndrome pour les Magnoliidae et les Angiospermes basales en général.