This BioProvince (as defined by Armen Takhtajan) forms a zone mostly between 500-700 km wide extending from the Sudan-Ethiopian border westwards to the Atlantic coast of Senegal. The wider eastern border extends to the basin of Lake Victoria and includes the northwestern corner of Zaire, northern Uganda and two small parts of Kenya. The area is mostly composed of level or gently undulating ground below an altitude of 750 m. In the west, land above 1000 m is principally confined to the Jos Plateau and the Mandara Plateau while in the east the inactive volcano Jebel Marra rises to a height of 3057 m. Continental sedimentary rocks, known in Sudan as Nubian Sandstone, make up much of the bedrock of Sudan. The sediments were deposited mainly during the Cretaceous period. In the extreme southeast there are the crystalline mountains of Imatong (3187 m), Dongotona (2623 m) and Didinga (2963 m). The climate is characterised by tropical summer rainfall and severe drought in the dry season but frost is unknown. The flora comprises some 2,750 species of vascular plants of which about one third is endemic. However, there are no endemic families and just a handful of endemic genera including Butyrospermum, Haematostaphis and Pseudocedrela, all of which are monotypic.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|