Baobab is the common name for each of the nine species of tree in the genus Adansonia. The generic name honours Michel Adanson, the French naturalist and explorer who described Adansonia digitata.
Of the nine species, six are native to Madagascar, two are native to mainland Africa and the Arabian Peninsula, and one is native to Australia. One of the mainland African species also occurs on Madagascar, but it is not a native of that island. It was introduced in ancient times to south Asia and during the colonial era to the Caribbean. It is also present in the island nation of Cape Verde. The ninth species was described in 2012, and is found in upland populations of southern and eastern Africa. The African and Australian baobabs are almost identical, having separated less than 100,000 years ago.
Baobabs 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 has since split into two parts, so the widest individual trunk may now be that of 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 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 one of the oldest known angiosperm trees