Page 37 - Silver Lakes August 2021

NATURE

the mimosa-like blossoms. The blossoms
metamorphose into knobbly crescent-
shaped pods that provide rich fodder for
countless browsers, domestic and wild.

The gathering in Australia deemed that
because of the international rules of plant
classification, only Australia had the right
to use the title ‘Acacia’. As a result, South
Africa was obliged to change the generic
name of all its 83 species of acacias.
Overnight, Acacia karroo became Vachellia
karroo.
Likewise, the umbrella tree and the black
thorn and the knobthorn, along with all
the rest of the acacias can no longer be
referred to as acacias.
Three dozen botanists, led by South
African botanist Eugene Moll, claim the
ruling goes against the normal rules of the
system devised more than 200 years ago
by the Swedish scientist, Carolus Linnaeus.
The system, adhered to worldwide, gives
a scientific name to all living organisms, parts, was regarded as a troublesome Revil Mason, Witwatersrand University
alive and extinct. The botanists (on our invasive species. Its spread was the result archaeologist, identified three Iron Age
side) insist "the accepted rule is that the of injudicious veld burning (sweet thorn foundries in Lonehill and carbon dating
earliest published name has precedence" saplings are pretty much fireproof) and found they were at least 800 years old. For
and the first species named ‘Acacia’ was an overgrazing, which changed the nature more than six centuries iron was extracted
African tree described in 1753. of so much of South Africa’s savannah, from iron-bearing pellets (ferricrete) that
creating ideal conditions for the tree. still crunch underfoot – but the fuel for the
Paradoxically, the spelling of the sweet furnaces? From where did that come? The
thorn’s species name, which was, in error, The presence of sweet thorn is an indicator surrounding Highveld is to all intents and
spelt ‘karroo’ cannot be corrected to the of sweet veld whose soils are good for purposes empty of native trees yet to forge
proper spelling, ‘karoo’ because of the grazing as well as for crops. Hydrologists a single hoe blade or a spear would, said
system’s rules. view its presence as an indication of Mason, have needed charcoal from the
ground water. trunks of two thorn trees measuring 20cm
But, as Shakespeare put it, “A rose by any in diameter at breast-height. It meant the
other name would smell just as sweet,” A single acacia in the Namib Desert can original landscape of the Highveld must
and Vachellia karroo remains just as sweet assume the importance of a geographical have been well wooded – an open forest
as ever. Its sweetness comes from the location and be marked on maps; it might of spaced out acacias and karee trees. So
thick sap that oozes from wounds in its be the only tree seen during a day’s hike. It it can be said that thorn trees fired our first
trunk – it has been used as a confection would have resulted from a seed dropped step to becoming a manufacturing nation.
in Africa probably for as long as humans by a passing bird just before a once-in-a-
have existed. It is still used today by decade rain shower enabling it to survive Apart from its usefulness as fuel wood
confectioners. Many mammals, birds, long enough to send down an exploratory and for making charcoal, the sweet thorn
reptiles and insects relish it, including root to seek water. Its lacy, compound was used to make fence posts and ‘living
the giant kori bustard whose name in leaves would have captured the droplets fences’ by being grown as a thorny hedge.
Afrikaans is gompou, meaning literally, from the nightly mists that roll in from
‘gum peacock’. the Atlantic and, before the relentless sun The sweet thorn’s inner bark was used
emerged, the droplets would have fallen to make rope, and proved essential for
Acacias, as botanists informally continue like rain into the tree’s shade. During this making barges to cross rivers and for
to call the genus, are found across the time the tree’s bark will have lost its rich wagon-making.
world including America. There are more chestnut red colouring to become rough
than 1 000 species in Australia and 300 and grey. The bark, incidentally, has been For centuries, communities have viewed
elsewhere. used for centuries for tanning leather. a mature acacia – and many still do – as
their local pharmacy. Its pods, leaves
I recall the renowned botanist, Dr AOD During a drilling operation in the dry west, and roots are believed to be effective
‘Bertie’ Mogg, with whom I travelled Mogg recalled workers hitting a sweet for making concoctions to relieve pain,
on many local botanical surveys in the thorn’s tap root 120 feet (40 metres) down, for the treatment of open wounds, to
1970s, telling me how the sweet thorn measuring an inch thick (25mm). He said relieve constipation, and as a remedy for
was rare along South Africa’s eastern side, it was wet and “smelt like a drain”. diarrhoea, colic, malaria, impotency, sore
especially in eastern Natal, but that it was throats, coughs, convulsions, abscesses
spreading. By the time Mogg died in 1980, The sweet thorn’s contribution to human and ulcers – and even osteomyelitis.
it had reached the Indian Ocean and, in culture has been considerable. Prof

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