Posts Tagged ‘plants’

A true desert bloom crowned in the springtime by large disc-shaped crimson flowers, Hoodia has received much attention over the years, not for its ability to store moisture and thrive in arid areas or for its exquisite blooms but rather for its use as an appetite suppressant. In the last decade it has been universally acknowledged that the San/Bushmen, the oldest inhabitants of southern Africa, own the rights to the indigenous knowledge of the plant, but that has not always been the case.



The plant was used by the San for millennia as an appetite suppressant and thirst quencher (also as a treatment for high blood-pressure, diabetes and as a cure for abdominal cramps, haemorrhoids, tuberculosis, indigestion and hypertension), long before it was sought after in a western world in its battle with obesity.

The species of most interest in the family Apocynaceae for its appetite-suppressing qualities is Hoodia gordonii found predominantly in southern Namibia and north-western South Africa. The spiny-stemmed succulent grows in gravel or shale plains, Kalahari sands or on dry stony slopes. It can tolerate temperatures exceeding 40˚C and as low as -4˚C. Incredibly, a single plant can have as many as fifty branches growing from its base, can grow up to a metre high and weigh as much as thirty kilograms. Although eye-catching, the flowers referred to as stapeliads, are only attractive to its pollinators – flies and blowflies – with their strong carrion-like odour.

Hoodia with yellow flowers in the Gondwana Cañon Park.  Photo: Mannfred Goldbeck

Hoodia with yellow flowers in the Gondwana Cañon Park. Photo: Mannfred Goldbeck

The first Europeans to encounter Hoodia gordonii were Paterson and Col RF Gordon, who in December 1778 found specimens in the Upington area. Botanist, Francis Masson, recorded the use of Stapelia gordonii on his visits to the Cape around the same period. It was later transferred into the Hoodia genus, so named after dedicated succulent grower, Van Hood.

Hoodia is a protected plant in Namibia and a permit is required from the  for cultivation or harvesting, relocation or trade. It is also listed on the Convention of International Trade in Endangered Species of Fauna and Flora (CITES), Appendix 2, regulating international trade.

The Council for Scientific and Industrial Research (CSIR) in South Africa began to include Hoodia in its projects as early as 1963 and in 1995 it filed for a patent application for use of the active components (it had isolated the active compound – P57) responsible for appetite suppression. It later signed licensing agreements with UK pharmaceutical company Phytopharm that in turn sub-licensed the rights.

Hoodia bainii, issued in 1973, artist: Dick Findley

Hoodia bainii, issued in 1973, artist: Dick Findley

In June 2001, a South African-based NGO, Biowatch South Africa, with assistance from the international NGO, Action Aid, alerted the foreign media to the fact that the San had not been involved in the development or commercialisation of the Hoodia products, leading CSIR to enter into negotiations with the San. They were represented by the Working Group of Indigenous Minorities in Southern Africa (WIMSA), the South African San Council and the San Institute of South Africa (SASI). This culminated in the CSIR and the South African San Council signing a benefit-sharing agreement in March 2003 with the San receiving a percentage of the royalties.

In August 2004, the San Trust, formally named the San Hoodia Benefit Sharing Trust, was registered, with 75 percent of all Trust income to be equally distributed to the San Councils of Namibia, Botswana and South Africa.

The bottles of weight-loss products lining pharmacy shelves have little resemblance to the hardy desert plant that survives in the Namib Desert, its soft sensual bloom belying its tough existence, and its recent history is far removed from the time when the San still freely lived off the land and roamed the southern sands of Africa.


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The designer’s and builder’s name is Siegfried Schnebel. “This is a windmill which I designed and built myself”, he explains in an interview in his house near Brakwater north of Windhoek. “There is an unusually strong supply of water there, just 30 m below the surface. I wanted to utilize it for irrigating orchards and fodder plants.”

There is farm Neiseb which Siegfried Schnebel took over from his father, Wilhelm, in 1985. The fact that Neiseb has a lavish supply of water was already known during colonial times. “Wells for ox-wagon transports were sunk in this area in those days. The lower one of the two cisterns on my tower was part of the former drinking trough for the oxen. It is made of 5 mm steel plates.” While his father owned the farm, 60 cubic metres of water could easily be pumped per hour without any noticeable effect on the water table. It seemed obvious that this abundance of water should be put to good use. Wilhelm Schnebel had already planted 400 citrus trees, 50 sultana vines, 700 prickly pears (ideal fodder) and a little lucerne. “Date palms also thrived like weeds”, Siegfried Schnebel recalls.

Gigantic windmill on a massive tower

“The problem is that you need a powerful engine for pumping the water to the surface, and it wouldn’t have been worth it to install smaller windmills at several smaller boreholes.” The largest windmills on the market, however, weren’t sturdy enough to hold out against the high winds in the area, he says. “So I came up with a construction of my own, specially designed for the requirements of my farm.”

A large wheel was necessary for the high output of the pump. “But the larger the wheel the bigger the problems in very windy conditions”, Siegfried Schnebel explains. A standard wheel with metal blades was not an option. Too rigid, says Schnebel. “All is well as long as there is just a light wind. But in order to cope with high winds one needs to be able to adjust the angle of the blades to the direction of the wind, to reduce the pressure on the tower.” What is more, metal blades would have made the large wheel too heavy. “Therefore I used steel tubes for the wheel’s rim and axle only; the spokes are made from light wire rope and canvas is attached to the rope. This reduced the wheel’s weight to about 100 kg only, despite its diameter of 9.5 metres”, Schnebel points out with a hint of pride in his voice.

Resourceful handyman: Siegfried Schnebel

To make the sails equally suitable for strong and light wind they were arranged in two circles. In the inner circle their angle to the wind direction is 10 degrees, in the outer circle it is 45 degrees. Siegfried Schnebel explains: “Due to the higher leverage of the sails in the inner circle they push the wheel when the wind is blowing strongly, while the outer circle keeps it moving when the wind is light.” The blades of customary windmills are set at a 10 degree angle, Schnebel says, and turn out of the wind when it becomes too strong. The unusually long axle of his construction also serves a purpose: joined to the rim at the top with wire rope, it maintains stability and prevents the sail-covered wheel from turning inside out like an umbrella in heavy gusts of wind.

As for the rest of the construction, stability is the most important criterion as well. “The foundation is 10 m square and 2 m deep, made of carefully packed stones and diagonal iron struts which support the vertical steel pillars”, says Schnebel. “After all, the whole tower has a total weight of some 50 tons when both cisterns are full.” According to his estimate the total height of his windmill is a little less than 25 m: “The wheel’s axle is about 20 m above ground.”

Axle and rim are linked by a mesh of wire rope

Costs were also an important consideration when building the windmill. “Since the farm didn’t yield much I tried to get hold of construction material as cheaply as possible”, Schnebel recalls. “I got most of it from my brother’s scrapyard; Fritz ran a locksmith’s workshop in Lüderitz and later in Windhoek.” Building and constructing, by the way, was done without drawings or model calculations. “I simply experimented a bit, trial and error”, Schnebel says. But the experimenting wasn’t altogether by chance. Schnebel studied mathematics at the University of Stellenbosch and completed a Master of Science degree. He taught mathematics, physics and chemistry at the German School in Lüderitz for years.

In 1997 the work was almost complete. Only the irrigation system had to be installed. But at that point Siegfried Schnebel felt compelled to sell the farm. “It just didn’t yield enough”, he says. And so the giant windmill was never really in operation. He once got it going for the camera crew of NBC television. The documentary was aired in 2001.

Today the tower, citrus trees and prickly pears are all that remains of the plantation which was once envisaged at the foot of the Tiras Mountains on the fringe of the Namib. And a small café, closed down again since then, on the neighbouring farm on the opposite side of the road, overlooking the striking structure. Many a traveller stops and reaches for his camera. Small wonder. In the grassy plain the colossal contraption, welded together from pieces of scrap metal, looks like the futuristic work of an off-beat artist. Who knows, it might still turn into a tourist attraction one day – as the Peculiar Tower of Tiras.

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Gladiator, issued in 2003, artist: Helge Denker

Gladiator, issued in 2003, artist: Helge Denker

At the start of this millennium Namibia caused worldwide headlines when biologists found a mysterious insect on Brandberg Mountain which did not fit into any known genus, family or order. In the end a whole new order had to be established – for the first time since 1914. Thus some scientists felt that the discovery of the ‘gladiator’ was as sensational as finding a life mastodon or sabre-toothed tiger.

The predatory insect was nicknamed ‘gladiator’ because parts of it are covered with spiky armouring reminiscent of the legendary warriors of ancient Rome. The name ‘heelwalker’ is also used by some because the insect always points the feet on its hind legs away from the ground and puts down the heels only.

The scientific name Mantophasmatodea is derived from Mantodea (the praying mantis) and Phasmatodea (the stick insect). The gladiator, unlike the praying mantis, grabs its prey with both its fore and mid legs, and in contrast to the stick insect its first body segment is the largest. Nor does it feed on plants.

Between 1.5 and 4 cm long, the gladiator has a size that made many scientists wonder why it took so long to notice this insect. It does, however, live rather inconspicuously: it is nocturnal and prefers to stay in the shelter provided by clumps of grass and rock crevices. Males are smaller than females and have to beat a hasty retreat after mating, otherwise they may get eaten.

The discovery of the gladiator insect turned into a piece of detective work: At the Max Planck Institute for Fresh Water Research in Plön, Germany, Ph.D. student Oliver Zompro is busy examining a fossil insect trapped in a drop of amber which is 45 million years old. He concludes that the insect cannot be classed with any of the known categories and turns to the Museum of Natural History in Berlin. There he comes across a specimen which appears to be related to his object of research and which had been collected in the German colony of South West Africa in 1909. Reason enough for the exciting assumption that an insect, which over the past 45 million years became extinct in Europe, had possibly survived in Africa.

Enquiring at the insect department of the National Museum in Namibia he learns that indeed they have a similar insect – in fact it was received only a few days earlier. Namibian biology student Martin Wittneben found it on an excursion to Brandberg Mountain in north-western Namibia. The tiny creature had come into his camp and he was unable to identify it. This was a very lucky coincidence, as Wittneben had of course taken down the GPS coordinates.

The predatory gladiator insect in its typical environment at the Fish River Canyon. Photo: EduVentures

The predatory gladiator insect in its typical environment at the Fish River Canyon. Photo: EduVentures

Zompro decided to travel to Namibia. In March 2002 he joined an expedition to the Brandberg, jointly sponsored by Conservation International, the Max Planck Institute and the National Museum of Namibia. The team consisted of 16 entomologists from Germany, Britain, South Africa, Namibia and the United States. The scientists were dropped onto Brandberg and began a painstaking search on the stony, arid summit. Zompro collected a dozen of the insects and carried them back to his lab in Germany to study mating, feeding and other forms of behaviour in the insects. Aggressive tendencies became one area of interest — a couple of the insects apparently were eaten during the trip back.

After in-depth research it can be stated without doubt that this insect does not belong to any known genus, family or order. The last time this happened was in 1914. And so another new order was added to the 30 known ones – the gladiator or Mantophasmatodea.

Since then some 20 gladiator species have been identified and divided into 10 genera and 3 to 4 families. These species have so far only been found in southern and east Africa – more precisely in Namibia, South Africa and Tanzania.

In Namibia, by the way, Brandberg is no longer the only site where gladiators have been found. The inconspicuous predatory insect also occurs at the Fish River Canyon. On an expedition arranged in 2006 by EduVentures, an initiative of the National Museum of Namibia, to the northern parts of Gondwana Cañon Park biologists and students unexpectedly discovered three gladiator specimens.

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