Growth – The trees have a scruffy appearance and are frequently multi-stemmed and extensively branched. They grow very slowly and often in very gnarled and twisted shapes. Their boles are very often highly buttressed or fluted so the full diameter of the log is not available for use due to the deep intrusions of bark and sapwood that often occur. Photographs of end cuts of Dalbergia melanoxylon are notable because of the stark black color of the heartwood which is ringed by these irregular, sometimes petal-shaped buttress protrusions, all outlined in creamy-colored sapwood. Harvestable size is not reached until an estimated 70 to 100 years. Mature trees are typically between 4.5m and 7.5m high and rarely exceed 0.3 m. (1 foot) in diameter. In some tree databases tree size listings for African blackwood are often inaccurate, claiming 2 to 3 feet in diameter as normal. Only the rare tree in a highly protected environment has been found to be this large. As larger specimens have been harvested, the average available tree size has diminished over the decades of its use. The yellowish-brown bark on the main stem flakes off in long strips, and its smaller branches bear sharp spines 2-3 cm in length. The tree is semi-deciduous, losing many of its leaves over the dry season in common with most trees of its habitat. The flowers are small, white, sweetly scented and grow in tight clusters. They develop into greyish, papery pods each containing one or two seeds which are wind dispersed.

Habitat – Mpingo grows in an ecoregion of Africa called the miombo woodlands, which stretch across the continent from Angola in the west to Tanzania in the east. These woodlands are dominated by three primary species of the subfamily Caesalpinioideae which rarely grow in other habitats, namely Brachystegia, Julbernardia and Isoberlinia. Climatically the habitat varies from humid to semi-arid and tropical to subtropical or even temperate. Its soils are nutrient-poor, and vegetation can be sparse due to its long dry season. Nevertheless, these woodlands are vital to birds and animal species as well as to the livelihoods of many rural people, who depend on them for timber, fuelwood, fruit, honey and fodder for livestock. Because of its adjustment to this challenging habitat, Dalbergia melanoxylon has acquired adaptive characteristics like fire-resistance and incremental growth. Its incremental yearly addition of heartwood is one reason for its notable density. The heartwood of the tree at 12% moisture content has a density of 1230-1330 kg/m³, as compared to water with a density of 997 kg/m³. A blackwood log will not float in water.

Seedlings need to be carefully weeded because they do not successfully compete with other plants. It is known to grow in rocky soils where other plants cannot take hold. During its early years it develops an extensive system of roots to sustain its life during the long months of the African dry season. Its leaves provide fodder for the great migrating herds along the Serengeti plain; its roots have a nitrogen-fixing effect and so serve to increase the soil’s fertility. The more mature trees have the ability to survive the sweeping grass fires of the miombo woodlands when they are not too intense, but mpingo seedlings are highly vulnerable.

Distribution – The woodlands which once stretched from Senegal to Ethiopia and south to South Africa have suffered considerable decline due to population increase, overharvesting and poor management. Consequently, although mpingo is noted as growing in numerous countries, now the main stands of African blackwood occur in southeastern Tanzania and northern Mozambique. Most blackwood is harvested from these two countries. Other countries in which it has been noted, but is not commercially viable are Angola, Botswana, Ethiopia, Kenya, Malawi, South Africa, Sudan, Uganda, Zambia and Zimbabwe, and to a lesser extent, in the Central African Republic, Chad, Cote d’Ivoire, Burkina Faso, Nigeria, Senegal and Zaire. For information on the current conservation status of the tree, see “Conservation Status of Dalbergia melanoxylon in the 21^st Century.” 

Medicinal Uses – Dalbergia melanoxylon is well known throughout eastern Africa as a medicinal tree, usage being made of its bark, leaves and roots, and it is found in many listings of African medicinal plants. Since there is such widespread use of native plants for healing in Africa, the loss of habitat for the mpingo tree has significant detriments for the people, because such plants are regarded as ‘irreplaceable’ species.

These are some of mpingo’s medical usages: 1) Root decoction: treatment of abdominal pain, hernia and gonorrhea. Also used for abortion and as an anthelmintic (for intestinal parasites). 2) Smoke of the burning root is used for headache, rhinitis and bronchitis. 3) The bark is an antidiuretic. 4) The leaves are used for throat inflammations, heat problems, syphilis, gonorrhea, and dysentery. 5) Use of heartwood: use a sharp knife to scrape the heartwood and mix the shavings with skin lotion or oil to treat skin diseases.

Its leaves can be mixed into a goat soup that is said to be efficacious for the relief of backache and joint pain. In Kenya the tree has become over-exploited for its use in curing coughs and stomach pain. For centuries the Venda people of South Africa have used the bark as an anti-bacterial. In 1993 a revue in the Journal of Ethno-pharmacology reported on scientific tests carried out at the Department of Pharmacy at the University of Zimbabwe verifying this use, determining the existence of anti-microbial activity relating to use of the bark of Dalbergia melanoxylon. Several more recent studies have verified this use. 

Mpingo is also important in cultural and ceremonial practices, including bathing a newborn infant in a concoction made from the tree’s pounded leaves mixed with water to ensure that the baby grows strong. The Chagga people of Kilimanjaro have a traditional belief that if you have a piece of mpingo wood in your house, it will bring peace and everybody in the family will be happy with one another.