African Wildlife & Environment Issue 80

FAUNA, FLORA & WILDLIFE

Figure 20. When trees grow fast under optimum conditions some spines persist on the branches

Figure 22. Gum coagulated in a drip from a wound left by the removal of a branch

dominant, but the canopy can also be fairly flat and at times the trees are shrubby and multi-stemmed. The species is known to grow reasonably quickly and has spectacular yellow flowers in spring. If the bark is damaged it exudes a gum that is carbohydrate rich – a fact not lost on indigenous people who harvested the gum for food, and baboons are known to damage the bark to cause the gum to 'blee'” so they can eat it. Figure 21. Where the bark is damaged a sticky gum forms and drips down (see Figure 22)

Figure 23. Showing how large some spines can get - from trees in the Little Karoo.

Trees can certainly be top-killed by fire, and mostly they resprout strongly; and in some cases, they are considered to be invasive. Notably in the Eastern Cape, where the seminal work done by people such asWinston Trollip, when he was at Fort Hare in Alice, where he had experimental plots using Boer Goats as agents to utilize and control the spread of the trees. Postscript In a future article maybe I should spin a yarn about why acacia spines developed and then persisted? There are also other factors that have made me re- think much of what I once knew, read in the more recent literature, and many still believe that could well be myths. The older I get the more I realise that there is still much to learn!

Prof Eugene Moll Department of Biodiversity and Conservation Biology

University of the Western Cape eugenemoll74@gmail.com

Figure 24. A section through one of the large, fat spines to show the pith filling

22 | African Wildlife & Environment | Issue 80 (2021)