We find ourselves midway through August. Leaves have fallen and the grass is straw yellow. The bush is covered in colours from chocolate brown to pale cream and the trees look stark, except for one.
We embark on drive at day break, the ever-comforting winter sun begins to warm the land. As this warm air rises, a pleasantly sweet, floral smell drifts across the landscape and everyone sighs with satisfaction. A thorn tree with its unique knobbly trunk and branches breaks the horizon. The canopy is filled with soft yellows and creams; the tree and others like it are in full flowering bloom and their scent permeates through the surrounds. It’s commonly known as the Knob Thorn.
Knob Thorns flower between the months of August and November; often being the first Spring tree to come into bloom at Londolozi, a sure sign that the season is changing. Giraffe shape the beautiful crown as they feed. Vervet monkeys often descend from the tree tops with a face covered in yellow pollen. Elephants favour the bark of the tree, which is easily stripped and is reported to have properties that help fight tooth decay. Mixed bird parties are heard and seen fluttering in and out of the canopy, with white-bellied sunbirds in particular flocking in to take advantage of the nectar-laden flowers. The Knob Thorn can be seen as a tree of life.
The cream yellow crown of a Knob Thorn in full bloom.
The unique knobbly appearance on the branches and trunk that give the tree its name. These knobs are more prominent on younger trees and are said to have medicinal uses. Knobs can be crushed and placed on a tooth, relieving tooth ache.
A giraffe stretches its neck to feed on the protein-rich flowers.
The soft, powdery appearance of the flowers. These are responsible for the beautifully sweet smells that fill the air as one explores Londolozi on game drive at this time of year.
Knob thorn trees play host to hole-nesting bird species such as woodpeckers and barbets and they attract the larvae of the Dusky Charaxes (a species of butterfly). With the wood being relatively termite-resistant, the dead trees are likely to remain upright for longer than others, allowing a more permanent home for these birds. White backed vultures are also known to make regular use of knob thorn trees as nest sites.
It is not only birds however that have a special relationship with the tree: up to 45% of their pollination is done by giraffes! As the giraffes feed, their long, slender faces pick up pollen off the flowers, which is then deposited on neighbouring trees growing nearby as well as trees many kilometres away.
Commercially, knob thorns have a very hard wood and so have been used as fence posts and mine props. The iconic scene of an African camp fire is often stoked with the wood from this tree as it provides hot and slow-burning endless coals. Traditional fighting sticks and carvings are often whittled out of knob thorn wood
As the bark peels quite readily, and because they have many thorns, knobthorns are seldom used by leopards as vantage points or to stash kills in. The Mashaba female makes an exception. Photograph by James Tyrrell
As trees form such a sedentary part of the bush landscape, they are often overlooked as important role players in the ecosystem, whereas in fact they are some of the crucial components of a healthy and productive habitat. Whereas not all species are as important as others, some have such a wide variety of uses – both for humans and animals alike – that they are almost indispensable.
The knob thorn, whilst rarely featuring on regular bush-goers’ ‘favourite trees’ list, should certainly rank up there as one of the most interesting and widely used. One just needs to look a little deeper to see what an amazing and valuable part of the bushveld it forms.
Very interesting! Thanks for sharing–makes us all appreciate what one species of a tree can mean to the entire ecosystem!
Who would have thought a tree could have such an interesting background. When viewing animals in the bush, I can honestly say I didn’t pay much attention to the trees except for those acting as props for leopards. I appreciate the botanical lesson.
Great read Al, very informative!
Alex, very interesting write-up and wonderful photos!!
Thanks for this interesting Blog Alex. I am a tree hugger and found this interesting. Without trees we would not survive. They do indeed play an important part in our world.
Reading through some older blogs I luckily found this one Alex. I love knob thorn trees. I have got one growing in my garden that is doing very well. It is only 2 metres tall but a beautiful speciman. When you drive in spring through the bush all that you see is this lovely creamy color for kilometres. We try to go into the bush every spring just to see the spectacle. We learned on game drives at Londolozi recently that what we thought were dead leadwood trees were actually knob thorns debarked by elephants.