Brachystegia spiciformis

Msasa
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Fabales
Family:	Fabaceae
Genus:	Brachystegia
Species:	B. spiciformis
Binomial name
Brachystegia spiciformis Benth.

Brachystegia spiciformis Benth., commonly known as Msasa, is a medium-sized African tree having compound leaves and racemes of small fragrant green flowers. The tree is broad and has a distinctive amber and wine red colour when the young leaves sprout during spring (August-September). It grows in savanna, both open woodland and closed woodland of Southern and Eastern Africa, mostly Tanzania, Zambia, Zimbabwe and Mozambique. The word Msasa is commonly used as a proper name in African place names. The word also means 'rough plant' in Swahili. Other common names: Mundu, Myombo, Mtondo (Tanzania), Muputu (Zambia). The plant is known in the Venda language as mutsiwa, which means 'the one that is left behind'. An outlying population of Brachystegia has recently been discovered in the Soutpansberg mountains of northern South Africa. This tree is a protected species in South Africa.

Distribution

The Msasa is a tropical tree and grows best in open woodland where there is a sharp distinction between wet and dry seasons. The northern end of its range is near Tabora in Tanzania (about 5° S) and its southernmost extent is near Quissico on the coast of Mozambique just outside the tropics (about 25° S). Msasas need a minimum of around 500 mm rain although the amount of rain in the summer growing season is more important than the annual rainfall. It needs a mean annual temperature of around 19 to 20 °C. It does not thrive under a combination of cold and wet conditions and like many tropical plants it requires a hot dry period before the onset of the growing season.

Appearance

The tree typically reaches a height of about 16 metres although it is less tall in more drought-prone areas. In central Zambia and eastern Angola, magnificent specimens of about 18–19 metres are common due to the reliability of heavy rain during the growing season. It favours inland situations at an altitude of around 1000–1400 metres (due to the sharp difference between day and nighttime temperatures) although it grows down to sea level at its southern extremity. The tree presents a series of changes according to the seasons. It starts to lose its leaves as the cool season begins in late May (somewhat sluggishly) and by early August it is bare or nearly so. In late August as temperatures rise again, the new leaves are produced. These are often bright red in colour, but vary from almost purple to brownish in different individuals. The colour shifts to deep green over a period of 10–20 days. The insignificant flowers appear after the new leaves and these are followed by the dehiscent pods (about 12–15 cm in length) in April. The pods split open with a loud noise and the flat seeds (about 2 cm across) are flung away.

Ecology

The Msasa is ecologically dominant over large areas of central Africa where sufficient summer rainfall is received. In many parts of Zimbabwe, Zambia and Malawi, it is the dominant woodland tree and its colourful springtime foliage is striking seasonal marker. It can withstand light frost as long as little rain falls during the cool season such as on the Mashonaland plateau, where it is often co-dominant with the similar Mnondo (Julbernardia globiflora). Further north it is less dominant but it reaches its greatest size. The Msasa develops heavy spreading boughs and a shapely crown and mature specimens are valued in parks and gardens. However, it grows very slowly and so is seldom grown in cultivation.

Uses

The pale brown and heavy wood is not durable and is not useful to make most articles or furniture. However, the Msasa tree is widely used for fuel, both as charcoal and firewood. It is often heavily branched and in parts of southern Tanzania the hard wood is highly sought after. In southern Tanzania B. spiciformis has several medicinal applications including using the roots to treat dysentery and stomach problems. It is an important shade tree. The leaves are known to be a good fodder and would likely provide good mulch. The species is nitrogen-fixing.

Other uses

It is used for beehives, and sometimes for boats and general construction. It is considered to be a rather inferior general purpose timber.

References

• Dale, I.R. & Greenway, P.J. (1961) Kenya Trees and Shrubs, p. 97.
• Coates Palgrave, K. (1997) Trees of Southern Africa, Struik Publishers