Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"

On Tuesday, 6th of February, a small but dedicated team set out to find a very rare tree. I was part of the team, as were Bronwyn Egan, Troos van der Merwe, Ntsakisi Masia, and Kamogelo Solomon Modimola. The trees we were after were Sekhukhune Thorn Trees, Vachellia sekhukhuniensis. This tree is not in any of my tree guides, since it was only recognized as a new species after those guides were published. It had only been seen a few times, and as far as we knew, the last 'official' sighting was in 2007. The Sekhukhune Thorn has previously been considered a form of the extremely widespread and variable Sweet Thorn, Vachellia karroo, but with further study, several forms have gained recognition as full species. This is just business as usual in the exciting field of botanic taxonomy!

So, there is some responsibility on the shoulders of botanical explorers to make sure just where these species grow, and how they are doing. South Africa is a growing country, with a lot of development taking place, at the same time as us not knowing much about the biodiversity of huge regions of our country. You have to realize that serious botanists are few and far between, so we have a mammoth task. So this time our focus was to try to locate some Sekhukhune Thorn trees, get an idea of how healthy their populations are, and to try to get seed for the Millennium Seed Bank with which Ntsakisi is involved.

Technology makes this job a bit easier! We now have GPS and we can pinpoint the locations of specimens, and refer to the pinpointed locations logged by other observers. We had a spot for the trees pinpointed, and headed straight for it. And, we found the trees immediately! They are growing close to the small town of Ga-Riba, north of the rather bigger town of Burgersfort. The village is surrounded by hills, and there we found the trees, visible from the road! We stopped and had a good look at them. They are small and rather spindly trees, but they have fresh-green leaves and attractive yellow pompom-like flowers. They would make good garden trees, if you don't mind the thorns! We spoke with the people on whose land we found them; we explained to that these trees only grew there and thus were special and precious. After sighting the first trees, and getting some botanical samples and seed pods which were not quite ripe yet (but Ntsakisi took some anyways, hoping that they may ripen so that she can gather seeds), we drove on a bit more, and found trees in two more places. In the town, we found a man who worked in a local graveyard, who rode with us to show us the way to the top of one of the higher peaks. There we enjoyed some great views of the surroundings; then we took him to his home, and wouldn't you know it, there were some of the Sekhukhune Thorn Trees growing as well!

Having found our trees, we could relax and explore a bit more. Sekhukhuneland, the region where we were, is a huge region that is mainly low-lying, hot and dry, but has numerous mountain ranges and hills, the slopes (especially eastern and southern) of which are cooler and moister. The part where we were, looked to be receiving more rainfall than the more low-lying parts. The vegetation was dense grass with lots of shrubs and trees forming thickets in places.

In one such thicket, Troos found some amazing Ceropegia ampliata plants. The flowers are quite large, about 7 cm in length, and very strange in structure. These flowers attract small flies and midges with their musty odour; they enter the flower through the openings in the tips but are then trapped inside by stiff, backward-pointing hairs, until the flowers wilt. This gives them plenty of time to gather some pollen. When the flower wilts, the insects can escape and, not having learnt anything, visit other flowers where again they are trapped, this time giving them time to deposit pollen and maybe pick up some more for the next flowers still. Ceropegia has numerous species in South Africa, each with a differently-shaped flower, and most are rare. This is in fact one of the commonest and most widespread ones, and this is the first time I've ever seen it in the wild.

The veld features lots of different aloes; the most prominent is the Cat's-Tail or Chestnut Aloe, Aloe castanea. These aloes grow in probably their millions on the hills. They differ from most other aloes in being branched and tree-like, but not as much as the proper tree aloes now classified in the genus Aloidendron. They're named for their long, chestnut-flowered inflorescences with prominent stamens protruding from the flowers making the infloresence look like a hairy cat's tail.

In between tufts of grass grew numerous small plants, including these striking Ledebouria with their bold leopard-like spots (see above). There are many different species in this genus in Limpopo, the centre of their diversity, but some are found in other areas of South Africa, and even extending into tropical Africa. They have subterranean bulbs, from which new leaves sprout each spring. Species can be recognized by different leaf shapes, patterns and arrangements. They bear small but attractive flowers coloured in green, pink and purple.

One of the shrubs that densely clothe the slopes is Euclea linearis, the Lance-leaved Guarri. These belong to the Ebony Family, which includes some of the largest rainforest trees with much-sought-after wood, but here these grow as low, dense, twiggy shrubs. They are tolerant of drought and also of toxic soils, which are frequent in Sekhukhuneland. The entire region is rich in heavy metals like chromium and platinum, and these metals, when concentrated in the soil, are toxic to most plants, but this gives an advantage to species that can tolerate them. The guarris are tolerant of a variety of minerals in the soil, and can even accumulate metals like iron and aluminium in their tissues! You can recognize them by their yellowish hue and very narrow, rather leathery leaves.

We found many members of the Coffee Family, Rubiaceae. This is one of the largest families of woody plants in South Africa. The majority are small trees or shrubs. Pavetta schumanniana, the Poison Bride's Bush is typical in shape, rarely growing more than 2m tall but reaching 7m under ideal circumstances. It is poisonous to cattle and goats, but not to horses and donkeys (nor, in smallish doses apparently, to small animals like rats, or to humans). The leaves, when held to the light, have dark 'dots' on them. These are bacterial nodules, small lumps of tissue in which colonies of bacteria live. These actually benefit the plant by fixing nitrogen from the atmosphere into compounds the plant can absorb, thus nourishing it. This shrub also produces large masses of delicate white flowers in attractive spring displays, like the other bridesbushes.

We also found a dwarf medlar-like plant growing amidst the grasses. These have small yellow flowers and proportionally large, round fruit borne at ground level. Plants like these are called geoxylic suffrutices. They're essentially trees driven underground! This helps them survive grass fires as well as heavy browsing by animals. I'm not quite certain what this species is, but it's also a member of the Rubiaceae. The fruits were not yet ripe, but are certain to be very tasty when they are, like all our local medlars.

A family abundant in the region, and to be sure over all of South Africa, is the Pea Family, the Fabaceae. Here (above) you see a small shrub with attractive soft, silvery leaves and pretty yellow flowers. Growing with them were these gnarly trees, with small compound leaves, curled pods and deep pink flowers with a yellow spot. I'm fairly certain that this is the Curly Caterpillar Pod, Ormocarpum kirkii. This species is largely confined to Sekhukhuland, and similar to the much more widespread Hairy Caterpillar Pod, Ormocarpum trichocarpum. Both are gnarly, slow-growing, small trees.

On our way back, we made a final couple of stops. The first was to get a good look at these abundantly flowering shrubs that clothed the hills in delicate pink. They are Ocimum tubiforme, another species restricted to the Sekhukhune region. They belong to the Sage Family, the Lamiaceae. This family is noted for its many aromatic members, many of which are used as culinary or medicinal herbs. This one has aromatic foliage as well as very attractive long-tubed flowers.

Our final stop was for some vigorous growing ramblers we saw alongside the road. We thought these might be the endemic wild grape, Rhoicissus sekhukhuniensis, but having taken a good look at these, I'm not sure. Still, they look unlike any other wild grape I've ever seen, so for the moment, that's a puzzle needing to be solved. Wild grapes of the genus Rhoicissus are scrambling shrubs or climbers, some very vigorous, and also bear edible fruits, though usually not as tasty as those of commercial grapes. But they are popular with birds and other wildlife.

That brings us to the end of our Sekhukhuneland expedition! We certainly will return to further monitor the trees. We definitely need to collect seeds so we can grow them in a couple of our local botanic gardens as safeguards. We need to find the limits of their distribution, some estimation of the sizes of the populations, and take stock of threats. Currently, the entire region is under pressure from rapidly expanding human populations and developments like farms, towns and especially mines. But the trees would tolerate low-intensity cattle herding, which is the traditional type of animal husbandry in the region. This offers hope for their future. The bottom line is to find ways to harmonize the impacts of people upon the animal and plant denizens of the wild lands.

Willem

11.03.24 Front Page

Back Issue Page