Mkongo, the hardwood tree from which the famous Zanzibar doors are made

Wood carvings on display for sale in Nyeri. Mkongo wood is good for producing decorative, carved pieces and in Kenya, where it is popular with wood carvers and high-end furniture makers, it is nearly commercially extinct. PHOTO | FILE | NATION MEDIA GROUP

What you need to know:

  • The tree is widespread in different habitats, from Kenya to Angola. It prefers deep, well-drained, sandy soils.
  • In southern Africa, leaves are cooked and eaten as a vegetable, according to Useful Plants of Nyasaland (1972) by Williamson J.
  • The seeds are also used as counters in board games like bao. The wood is used as firewood and for charcoal production. 
  • The wood is also good for producing decorative, carved pieces; known historically for making the beautiful traditional Zanzibar-style doors.

Afzelia quanzensis, known in Kiswahili as mkongo or mbambakofi, grows in dry low-altitude zones of between 0 to 1,800 metres above sea level. Annual rains range from 400 to 1,700mm.

It is known as a ‘spectacle case’ tree in English, because of the shape of its fruit. Other names include pod mahogany and Doussie.

The tree is widespread in different habitats, from Kenya to Angola. It prefers deep, well-drained, sandy soils.

Benefits

Mkongo produces a valuable hardwood and has been extensively exploited for this. It also provides edible leaves, medicines and beads. The species has been heavily logged for railway sleepers.

The tree has a symbiotic relationship with certain soil bacteria that form nodules on the roots and fix atmospheric nitrogen, some of which is utilised by plants growing near it. It is thus a very good agroforestry tree.

In southern Africa, leaves are cooked and eaten as a vegetable, according to Useful Plants of Nyasaland (1972) by Williamson J.

They are also used in the treatment of a range of conditions including gonorrhoea, chest pains, kidney problems, bilharzia, eye problems and snakebites.

A mixture of the pounded bark, combined with python fat, is used to treat eczema, a skin disease characterised by scaly lesions and intense itching.

Its black seeds and the orange arils surrounding them are often sold as curios or made into necklaces, according to the World Agroforestry Centre. 

The bark is a source of tannins and can be used to make ropes. Some pores of the wood contain a yellow dyestuff, which under moist conditions can discolour textiles, paper, or other cellulosic materials.

The seeds are also used as counters in board games like bao. The wood is used as firewood and for charcoal production. 

Natural durability

Timber from mkongo has good natural durability, thus treatment with preservatives is unnecessary, even in permanently humid conditions or in locations where wood-attacking insects are abundant.

It is used to make furniture in Tanzania and Kenya and is valued for joinery and makes attractive doors, window frames and flooring. 

The wood is also good for producing decorative, carved pieces; known historically for making the beautiful traditional Zanzibar-style doors.

It is in high demand and has been declared a protected tree in South Africa. In Kenya, where it is popular with wood carvers and high-end furniture makers, it is nearly commercially extinct. 

Its wood is now supplied by illegal loggers from as far away as Tanzania and Mozambique.

Illegal timber accounts for up to 30 per cent of its trade globally and is worth more than $100 billion, according to Interpol. 

A significant share of this illegally harvested timber is sold in European markets, according to Global Financial Integrity, a Washington DC-based organisation that tracks natural resources crime.

Propagation is through seeds, which cost Sh2,000 a kilo at Kenya Forestry Research Institute (Kefri) shops.

The institute also provides technical advice on selection of other good seed sources and how to sow them.

Mkongo seeds do not normally need pre-sowing treatment, but scarifying them by making a small scratch in the outer black coat can speed up germination.

The seeds are sown in flat seedlings trays with a 5:1 mixture of river sand and compost and kept moist. Germination happens after 28 days. 

Seedlings quickly produce a deep taproot and so should be planted in their permanent positions whilst still small.