The Acacia Family
THE ACACIA FAMILY
Acacia is a genus of shrubs and
trees belonging to the subfamily Mimosoideae of the family Fabaceae, first
described in Africa by the Swedish botanist Carl Linnaeus in 1773. [1] He also
gave the species name of A.nilotica, for the range along, the Nile
River.
The name (akakia) was given, by
Greek botanist-physician Pedanius Dioscorides (ca. 40-90) to the medicinal tree,
A.nilotica, in his book, Materia Medica. This name derives from
the Greek word for its thorns (akis, thorn). [1] There is some debate on the
Australians pinching our African name, but Professor Eugene Moll says; “We can still
and quite correctly as far as I am aware, use the old names, as long as we
quote the correct authors.” [2] Thomas Baines said in ‘Explorations in South-West
Africa’ that he classified Thorn-Trees by putting them into different classes:
“Class one, for tearing clothes; class two, for tearing flesh; class three, for
tearing flesh and clothes both together.” [3]
Acacia robusta Burch. [4]
Tree No. 183 and 183.1
English name: Splendid Acacia/Broad-pod
Robust thorn/Narrow-pod Robust thorn
Afrikaans name: Enkeldoring
isiZulu Name: umngamanzi; umnqawe
[5]
The literal translation of the isiZulu
name is ‘Stand by water’ [6]. The other Zulu name “umnqawe” is ‘smoking pipe’.
This may mean, ‘that the wood for these pipes came from this tree’. If anyone knows the correct information,
please inform us. This is a common tree, near rivers, and at the
coast. It is also fast-growing. One of
the thorn-trees better suited to Durban’s climate, therefore better to plant in
your garden, or in the Parks or in the streets. There are quite a few along the
north bank of the uMngeni River.
The distinctive bark is rough and
fissured and grey to dark brown. The spines are paired, straight to curved,
short on old stems, usually 7mm to 20mm in length. {4 & 5} The flowers are
white to cream scented balls, from June to September. They attract a lot of
insects. Birds and monkeys also favour this tree. The bark is used for tanning and
twine is made from the inner bark. [5] There is a Tree, currently, on the north
bank of the uMngeni River, that is used for Muthi purposes. Only small pieces
are taken off at a time, and in a way, that is not environmentally friendly, in
other words, all the way around. So, the Tree is on the way to being
ring-barked. We are not too sure, what is the medicinal value of this
particular species? Does anyone have a clue? Possibly incense? Some other
species of Acacias’ are used for
‘digestion’; ‘sic’.
Fodder and poison
Acacias are legumes, therefore
soil improvers. It is said they greatly improve the protein in the grass,
growing near. Under certain circumstances, Acacia
robusta is only slightly poisonous. This is in the form of prussic acid.
[3] If fresh plant material produces a certain amount of hydrogen cyanide, then
it is potentially toxic. If the acacia “leaves” lack the cyanogenic
glycoiside-slitting enzyme, that produces the cyanide, then they may be less
toxic than otherwise. [1] The most poisonous of the Acacias are usually
harmless, when they are browsed slowly by well-fed animals. They become
dangerous, through overstocking and overgrazing. Prussic acid side-effects are
also more poisonous if eaten faster. Wild animals or stock animals in the bush,
are seldom poisoned, because the hardness of the pods, makes them eat slowly
and in small amounts. The thorns act as a line of defence, as they prevent
animals from browsing foliage and young pods too quickly. Some farmers gave
their stock, sulphur/molasses as a protective measure against prussic-acid
poisoning. The danger of this poisoning is increased by excess moisture. Dry
leaves and mature pods contain less prussic acid. [3]
References
[3] Palmer, E. & Pitman, N.
1961. Trees of South Africa. A.A. Balkema, Amsterdam and Cape Town.
[4] Coates-Palgrave, K. 1981.
Trees of Southern Africa. 2nd Impression. Struik Publishers, Cape
Town.
[5] Boon, R. 2010. Pooley’s Trees
of Eastern South Africa. 2nd Edition. Flora and Fauna Publications
Trust. Durban
[6] Mzwandile Chili
Rosemary Harrison
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