Adansonia digitata

Adansonia digitata L.

Common names

Baobab, upside down tree (English); Mubuyu, Mulambe (Bemba); Mbuyu, Buyu, mkulukumba, mlambe, mlonje (Nyanja, Kunda).

The name ‘baobab’ is thought to be derived from the Arabic ‘bu hibab’ – ‘fruit with many seeds’ (Wickens). The English name ‘upside down tree’ refers to the appearance of the tree in the dry season when it is leafless and the branches look like roots sticking up into the air. The Latin generic name is after the French botanist Michel Adanson who collected this species in Senegal in 1757. The Latin species name refers to the digitate, ‘finger-like’ leaves of the tree.

General description and distinguishing characteristics

A massive, deciduous tree that can exceed 20 m in height, distinctive due to its stout, bottle shaped trunk which can reach dimensions of up to 10m in diameter. Bark smooth, reddish brown, greyish brown or purplish grey. Leaves simple or digitate, alternate at the ends of the branches or borne on short spurs on the trunk. Adult trees begin each season by producing simple leaves, then 2-3 foliate leaves, then 5-9 foliate leaves, which are up to 20 cm in diameter. Leaf stalk up to 16 cm long. The leaflets are sessile (stalkless) or with very short stalks and are elliptic, oblong-elliptic or obovate-elliptic, 5-15 x 1.5-7 cm. Flowers hang down on flower stalks up to 20 cm long, and are solitary or paired in the leaf axils. The flowers are large and showy, with a 3-5 lobed calyx, 5-9 x 3-7 cm; petals 5, white, overlapping 5-10 x 4.5-12 cm. Stamens very numerous, united below in to a staminal tube 1-5-4.5 cm long; ovary 5-10 locular; style extends c. 1.5 cm beyond the anthers; stigma with 5-10 lobes up to 8 mm long. The flowers bloom at the end of the dry season (Sept-Nov). Fruit spherical, ellipsoid to oblong-cylindrical pods covered in dense, golden, velvety hairs. They vary enormously in size, and are up to 20 cm long in southern-central Africa. The ripe fruits are filled with a dry, cream coloured pulp in which are embedded numerous dark brown to blackish seeds.

Range and habitat

Adansonia digitata occurs in most of sub-Saharan Africa. The genus Adansonia comprises nine different species, one of which occurs in Australia, two in Africa and the remainder in Madagascar. In the Luangwa Valley the baobab is found in riverine fringe woodland and thicket, mixed alluvial thicket, Combretum thicket and in Mopane woodland on sand. There is an exceptionally large and solitary baobab on Lundu Plain in the north of South Luangwa National Park.

Adansonia digitata can be confused with the closely related Adansonia kilima. In fact, A. kilima has only recently been discovered. The main difference between the two species is genetic; A. kilima is diploid (i.e. has two sets of chromosomes), while A. digitata is tetraploid (four sets). The two species can also be distinguished by their flowers which in A. kilima are smaller, have fewer stamens, different pollen and petals that don’t spread. Finally, A. digitata is found at lower altitudes – typically below 800 m – whereas A. kilima is found at altitudes ranging from 650 to 1400 m. Given this, it is likely that all of the valley’s baobabs are Adansonia digitata.