Madagascar, en forme longue la République de Madagascar, en malgache Madagasikara et Repoblikan'i Madagasikara, est un pays situé dans la partie occidentale de l'océan Indien, à proximité il y a le canal du Mozambique large de 415 km. Sa capitale est Antananarivo. Madagascar est souvent appelée l'« île rouge » Madagascar fait partie du continent africain (Afrique de l'Est) et de l'Union Africaine.
Durant la majeure partie du XIXe siècle, l'île est administrée par le Royaume de Madagascar, situation à laquelle l'invasion coloniale française de 1895 met fin. Le premier gouvernement malgache voit le jour le et en 1960, le pays figure parmi les premiers à gagner son indépendance dans cette zone de l'Océan Indien.
Adansonia is a genus of nine species of tree, including six native to Madagascar, two native to mainland Africa and the Arabian Peninsula, and one native to Australia. One of the mainland African species also occurs on Madagascar, but it is not a native of that island, and was introduced in ancient times to south Asia and during the colonial era to the Caribbean. The ninth species was described in 2012, incorporating upland populations of southern and eastern Africa.
A typical common name is baobab. The generic name honours Michel Adanson, the French naturalist and explorer who described Adansonia digitata.
Adansonias reach heights of 5 to 30 m (16 to 98 ft) and have trunk diameters of 7 to 11 m (23 to 36 ft). The Glencoe baobab, a specimen of A. digitata in Limpopo Province, South Africa, was considered to be the largest living individual, with a maximum circumference of 47 m (154 ft) and a diameter of about 15.9 m (52 ft). The tree split into two parts, so the widest individual may now be the Sunland baobab, or Platland tree, also in South Africa. The diameter of this tree at ground level is 9.3 m (31 ft) and its circumference at breast height is 34 m (112 ft).
Adansonia trees produce faint growth rings, probably annually, but they are not reliable for aging specimens, because they are difficult to count and may fade away as the wood ages. Radiocarbon dating is accurate, and has provided data on a few individuals. A specimen of A. digitata known as Grootboom was dated and found to be at least 1275 years old, making it the oldest known angiosperm tree.