A brown and papery, spiky, fried egg is what the seed pod of this
beautiful tree looks like. The pods remain on the tree long after
the leaves have fallen and make it easy to identify. It is one of
the two Trees of Year for 2003, the other being the red currant,
kiaat is a deciduous, spreading and slightly flat-crowned tree with
a high canopy. It reaches about 15 metres in height and has dark
bark. The shiny leaves are compound (divided into leaflets) and
characteristically hang downwards. An abundance of scented, orange-yellow
flowers appear in spring. These are carried in sprays. The flowering
time is rather short, two to three weeks only.
The kiaat grows in the warm, frost free areas in the northeast
of the country, extending into Zimbabwe, northern Botswana, Mozambique
and Namibia and northwards into other parts of Africa. It grows
in bushveld and woodland where the rainfall is above 500 mm per
year and it favours rocky slopes or well-drained, deep, sandy soil.
Derivation of name and historical aspects
This tree is part of the pea or bean family (Fabaceae). The genus
Pterocarpus has been placed in a further division of this
family (called a subfamily). The subfamily Papilionoideae has characteristic
pea-like flowers. The genus has been given a name which describes
the unusual seed pods, pter meaning "wing" in Greek
and carpus which means "fruit" in Greek. The central,
hardened seed case is surrounded by a broad, membranous wing and
is therefore called "wing fruit" or Pterocarpus.
The first "P" in Pterocarpus is silent and the
name is pronounced tero-car-pus.
There are roughly 30 species in the genus and these may be found
in the more tropical regions of the world. Four species occur in
southern Africa. The specific name, angolensis means "of
The brilliant dramatically red sap found in Pterocarpus gives
it the common name of "bloodwood". The wood apparently
bears some resemblance to the unrelated true teak from tropical
east Asia (Tectona grandis) hence the common name "wild
The kiaat is a larval food plant for the bushveld charaxes butterfly
(Charaxes achaemenes achaemenes) and squirrels, baboons and
monkeys feed on the seed pods in spite of the sharp bristles on
the seed case. Game animals browse the leaves and elephants have
been known to push the tree over. The wavy, membranous wing allows
the pods to float to the ground away from the tree.
Uses and cultural aspects
This graceful tree has very many uses and is much valued throughout
Africa. The beautiful timber is easy to work and is used for furniture,
implements and curios. The reddish brown heartwood is resistant
to borer and termite and also polishes well. The sapwood is pale
yellowish and furniture and curios often have the sapwood included
in the article. Kiaat is also used to make canoes because the wood
does not shrink and swell much. Historically there was trade in
this timber in the old Transvaal. This was on a minor scale and
fitted in with the seasonal cattle drives from the lowveld winter
grazing back to the highveld in summer.
The red sap is used traditionally as a dye and in some areas mixed
with animal fat to make a cosmetic for faces and bodies. It is also
believed to have magical properties for the curing of problems concerning
blood, apparently because of its close resemblance to blood. There
are many medicinal uses recorded for kiaat, including treatment
for ringworm, stabbing pains, eye problems, malaria, blackwater
fever, stomach problems and to increase the supply of breast milk.
The tree is sometimes planted around the chief's enclosure to make
a living fence. Baskets are also woven from the inner bark.
Growing Pterocarpus angolensis
The kiaat makes a stately garden subject for warm frost free areas
in South Africa. It casts a light shade and therefore will not shade
out lawn beneath it. It is not common in cultivation because of
difficulty with seed germination. Seed needs to be removed from
the hard seed case and then treated by filing the seed coat to allow
the seed to absorb water for germination to occur. Apparently even
with treatment, germination is erratic. It reportedly will also
grow from truncheons taken in October when the sap is rising. It
prefers a well-drained situation so will not enjoy shallow or heavy
soils, which will affect the appearance of the tree.
- COATES PALGRAVE, K. 1981. Trees of southern Africa. Struik,
- FUNSTON, M. 1993. Bushveld trees: Lifeblood of the Transvaal
Lowveld. Fernwood Press, Cape Town.
- JACANA & TWISISA. 1997. Sappi tree spotting: Lowveld.
LEISTNER, O.A. (ed.) 2000. Seed plants of southern Africa: families
Strelitzia 10. National Botanical Institute, Pretoria.
- MIGDOLL, I. 1987. Field guide to the butterflies of southern
Africa. Struik, Cape Town.
- PALMER, E & PITMAN, N. 1972. Trees of southern Africa,
vol. 2. Balkema, Cape Town.
PIENAAR, K. 1996. The ultimate book of trees and shrubs.
Southern Book Publishers, Halfway House, Gauteng.
- SMITH, C.A. 1966. Common names of South African plants. Memoirs
of the Botanical Survey of South Africa No. 35. Botanical
Research Institute, Pretoria.
- STEARN, W.T. 1983. Botanical Latin. David & Charles,
VAN WYK, B. & VAN WYK, P. 1997. Field guide to trees of
southern Africa. Struik, Cape Town.
- VON BREITENBACH, J. et al. 2001. Pocket list of southern
African indigenous trees: including selected shrubs and woody
climbers, edn 4, abridged reprint. Briza Publications
& Dendrological Foundation, Pretoria.
Witwatersrand National Botanical Garden
(With thanks to Geoff Nichols for photographs)