On the weekend of the 8th, 9th and 10th of December, 2017, I accompanied the PSG (Plant Specialist Group) of Mpumalanga to the Koedoes River Valley. Our host was Wiam Haddad, an ecologist working for the ZZ2 farms, which specialize in tomatoes and avocadoes, but also own a lot of wild land which is being managed as a nature reserve. The farms where our outing happened, are in the Koedoes River Valley area, not far from where I live, in the Limpopo Province of South Africa. The closest big town is Duiwelskloof/Modjadjiskloof. The Koedoes River (Kudu River) is not that major a river, but still an important water source, much utilized by the farms in the region. It flows mainly towards the northeast, through a very scenic and at present still largely undisturbed valley. The idea of the outing was to start compiling a plant list for the region; it would help Wiam very much with ecological decisions about the management of the veld, and also raise the prestige of the conserved region. The area through which we prospected, included various different habitats at altitudes of from about 600 m/2000' to over 1900 m/6300'. As Wiam said, it is a wonderfully mixed up region with several different kinds of vegetation coming together: grassland, savannah, woodland and forest. It is also in a transition region between the Wolkberg Mountains and the Soutpansberg Mountains, both regions being exceptionally rich in plant species. In the event we were very pleased to discover some plants previously only known from the Soutpansberg, growing here as well, much further to the south than was previously realized.
We stayed in nice chalets on the game reserve owned by the farm company, and went out on trips with Wiam leading. In addition to prospecting for plants, we saw much other wildlife, including some antelopes, lots of birds, frogs (coming at night to feed on flying ants and on moths attracted by the chalet lights) and especially an intriguing variety of insects. Wiam also took us to see some faint but still visible paintings of the San-Bushman people, thousands of years old, in the shelter of a rock overhang. The region is amazingly picturesque, and from the peaks of the surrounding mountains we could see the valley meandering below us, and distant vistas of the Wolkberg, Soutpansberg and Blouberg mountains.
As far as prospecting for plants was concerned, I found myself in a crowd where everyone was much more knowledgeable about the local plants than I was! The botanists had brought lots of identification guides and plant presses; after each day's collecting, they would press the specimens and pore through their guides to make certain of identifications. This made it evident just how little we still know about the plants of our country. One of the trees of which we made a definite ID is nevertheless a species still without a scientific or common name. As I said above, we also found trees which previously were considered to be endemic to the Soutpansberg region a hundred or so kilometres to the north. There was also much botanical confusion, with some species being very difficult to ID. The region boasts a bewildering diversity, including many different kinds and forms of Combretum (bushwillow) trees, which we somewhat helplessly tried to assign mainly to subspecies of Combretum collinum, and the families Rubiaceae and Celastraceae especially presented us with intense challenges. But we did indeed also found many lovely, and sometimes rare, species which we could positively ID, and we compiled the beginnings of a sturdy list for the region. If I'm not mistaken, we logged about 300 species in total.
There were a few highlights to the outing. One was the discovery of a small bulbous plant that might have been Chlorophytum radula, a very rare species that has only been recorded a few times in the region and that is declining because of much destruction of its grassland habitat - mostly turned into plantations of exotic trees. The other was the finding of a Strophanthus speciosus or Poison Rope in the forest - in flower! This species is so poisonous that we had to take care in collecting it, not to let the sap contact us. It has traditionally been used for making poison arrows. The flowers are weird and lovely. But in the end, for all of us it was simply a great outing to come out into a wild region and to experience the huge diversity of cool and unusual plants.
That gives you, I hope, a flavour of what we were doing. Now to share with you just a few of the photographs I took.
Here are some especially lovely flowers we found just about at the start of our exploration. It's a species of Chironia, members of the Gentian family. We have a few beautiful species in this family here in South Africa. We were very lucky to find so many species flowering during our trip. It is great to find them flowering in the wild, arranged by nature – it's like God's own garden.
This is a Crassula, a little succulent with wonderfully symmetrically arranged leaves in a rosette that looks like it's been squashed flat. Crassula is one of the largest of all genera of succulents, with a couple of hundred species in South Africa alone. They are astonishingly diverse, ranging from tiny ones just a few millimetres high and wide, to tree-like bushes that can stand 5 m tall. These ones were growing quite high up, between small cracks in rocks. In full sun they tended to turn red in colour, a pigment that protects the delicate leaves against sunburn.
Now for something amazing! This is a red-leaved rock fig tree, Ficus ingens. The species often grows on big rocks on hills and mountains, hence the name, but this individual grows on a flat plain in the valley. It is in fact a single individual, even though from the outside it looks like several trees forming a small patch of forest. What happened, is that as the tree grew its branches lengthened, drooping under their own weight until they touched the ground. Then they formed roots (since wild figs have the ability to form roots from any part of their trunks and branches) and anchored themselves in the soil, sending up new branches which in turn spread even farther. So now the tree has one very stout main trunk, and several secondary trunks formed by these re-rooting branches, spreading over a large area, rivalling the Wonder Tree of Pretoria, a similar compound tree of the related species Ficus salicifolia.
Here's a nice vista for you. We climbed onto one hill capped with a huge rock formation, from which we could look across to another huge rock formation which you see here. The photo doesn't quite do justice to the scale … just trust me that these rocks are gigantic, and so are the trees growing on them. These trees are related to the giant compound tree. They're small-leaved rock figs, Ficus tettensis. These trees germinate in hollows and cracks – often deposited there by birds – they grow and send out their roots to find further cracks, to collect water and nutrients. Eventually their roots become so long and thick that they can split even huge rocks, which then can give purchase to even more plants. Thus the rocks are ultimately eroded and reduced to gently sloping or flat land, as you see here in the landscape below. The trees with the soft, feathery looking leaves growing at the base of the rocks are White Syringas, Kirkia acuminata, forming a veritable forest in this hilly region. In the distance you see the floor of the valley, with some farmland.
On the big rock from which we looked out at the above big rock, there were also small-leaved rock figs growing, including this tiny specimen! It was growing in a small hollow on the bare rock, no soil visible. It looked like a little dumpling sprouting twigs and leaves! But quite healthy, and in time it may even start cracking the huge rock with its roots.
Here's another plant growing in cracks or hollows amidst the rocks. It is a Khadia media, a small member of the ice-plant or Mesemb family. This tiny succulent was only discovered and named in the nineteen nineties! Nevertheless, it is not at all rare, and has a fairly substantial distribution in the northern Wolkberg region. This is the farthest north and east that I've yet seen them. They've short, succulent leaves forming neat, rounded rosettes and pretty white flowers. The root sap from related species have traditionally been used for the brewing of beer. Not only is this sap a source of yeast for fermentation, there are also some alkaloid compounds in it which might give the beer a more potent 'kick'.
Oxalis is a diverse genus in South Africa. Some species have become weeds in suburban gardens, but most are modest and restricted to particular habitats. This charming little flowering specimen we found growing in shady, sheltered spots between rocks.
The grassland is amazingly diverse in plant species. People may not be aware of it, but most plant species in the grassland are species other than grasses. Here's a fine example, a Gladiolus longicollis, a member of the Iris family. Many gladioli have been bred for flower loving gardeners, mostly as hybrids and cultivars from South African species. Here you see what one of them looks like in the wild. Quite an arresting plant, though perhaps not 'glamorous'. Grasslands include some of the most threatened habitats in South Africa. They've mostly been turned to farm fields or to plantations of pine or eucalypt trees. Remaining patches are very vulnerable and need to be managed (for instance needing regular but not too frequent burning) to maintain plant diversity.
Now for something quite weird! These flowers are a species of Pachycarpus, a member of the Milkweed Family or Asclepiadaceae. The name means 'heavy fruit' and refers to the quite large follicle-fruits these plants produce after flowering. The flowers themselves are also large and striking, as you can see here. Pachycarpus are rather weedy species growing mostly in open grassland. I've tried growing them from seeds, but with no luck so far. These complex flowers are typical of the family, which also includes strange flowering species like the carrion flowers.
And not far from these plants, we found this! Milkweed locusts, Phymateus, indeed feed on plants of the milkweed family like Pachycarpus. From those plants, they absorb toxic compounds which make their own bodies toxic. They give warning of this through their bright body colours. Predators leave them alone; consequently they are bold and fearless. They're also large and slow-moving, which makes them easy photographic subjects compared to most other insects.
Related to these are what was for me the most charming find of the whole trip - Brachystelma coddii. The genus Brachystelma is large and amazingly diverse, with a huge variety of flower shapes, sizes, colours, patterns, and all manner of intricacies of formation. Nevertheless the plants themselves are often tiny and extremely difficult to spot, especially when not flowering. Most of them have subterranean tubers, from which small annual stems sprout. They're considered succulents, which is more appropriate when, as happens sometimes, the little tuber is partially exposed. They tend to be rare and localized. This is only the second species I found flowering in the wild. It is tiny ... flowers only about 7-8 mm in diameter, stems perhaps 2.5 cm/1" in length. But the shiny little leaves are gorgeous, as are the exquisite little flowers. There were many specimens which we found in only a single region, near to the highest point of the mountains (about 1900 m/6300' above sea level). Brachystelmas are relatives of carrion flowers, but this one didn't have any bad smell that I could detect.
Ferns are mostly associated with moist forests, but a few species in South Africa are hardy enough to grow in open, sunny spots in grasslands. Here is one, of which we found many, often in rocky places. I believe it is a species of Mohria.
For comparison, here is a fern we found in a forest patch. It has much larger, intricately divided leaves. I think it is a Dryopteris (which means 'wood fern').
A tree that tends to grow in the transition regions between forest and grassland, in the northeastern parts of South Africa from Kwazulu-Natal to Limpopo, and nowhere else, is the (South African) Wild Maple or Seemannaralia gerrardii. This is just a youngster, but healthy, and may in time become a fine tree. You can see the maple-like leaves there. It is not closely related to maples, actually being related to the Cabbage Trees of Africa, and in the Araliaceae, the Aralia or Ivy family.
The daisy family is diverse and prominent in our grasslands. This species is likely an Othonna, with semi-succulent leaves and stems, and bright yellow flowers.
Another member of the daisy family is Callilepis. These compound flowerheads are large and striking, about 2.5 cm/an inch in diameter. You see they are beloved of beetles, as were many of the flowers we found on the trip - most of which were consequently too ruined for good photographs! But some of these are still looking good.
These little plants, now, were not flowering - but their leaves are pretty enough! They're Ledebourias (or maybe the closely related Drimiopsis), a group of bulbous plants that is diverse in north-eastern South Africa, and which are more distinguished by their varioulsy spotted, striped and otherwise patterned leaves, than by their flowers - though those, too, can be quite pretty.
Here's another one, definitely a Ledebouria this time. Compare the spotting on these leaves with the above.
A relative of these is the Merwilla plumbea (which, along with Ledebouria, used to be included in the genus Scilla, the Squills). These were not flowering - their flowers are borne on tall inflorescences and shaded a delicate to intense deep blue - but the rosettes and exposed bulbs are quite striking in themselves.
Finally, here are more flowers. These are of a species of Xerophyta. The name means, more or less 'dry plant' since many species of the genus grow in dry regions or places. Here we found a few different species, mostly growing in shallow soil on top of the mountains and hills on or at the margins of rocks. These plants with their fibrous, grass-like leaves bear beautiful, brightly coloured, mostly pink to purple flowers. Unfortunately, beetles like the flowers too, and many of the flowers of the larger ones were chomped to pieces. But we were fortunate to find these intact ones!