Hoodia gordonii was first documented in 1778 by Colonel Robert Gordon, one of southern Africa's earliest explorers. It was found growing in what is now the Upington area of South Africa, close to the borders with Namibia and Botswana. It was originally placed in the Stapelia genus and was named Stapelia gordonii after Gordon, but in 1830 it was transferred into the genus Hoodia, named after Van Hood, the most well known exotic plant grower at the time.
Hoodia gordonii is often referred to as a cactus, which is unsurprising as it certainly has the characteristic spiny appearance of a cactus. However, it is correctly known as a succulent, from the Latin word succos meaning juice, a category of plants known for storing water. In fact all plants store some water, but succulents are especially adapted to storing water as they have evolved thickened tissues in their leaves, stems or roots for this purpose. This is an adaption to arid environments and the ability of succulents to make the most of water where it is scarce allows them to survive in habitats which are far too dry for most other plants.
The genus Hoodia belongs to the plant family Apocynaceae and is in the Trichocaulon order of a branch of the family called Asclepiadaceae. The genus contains more than 20 species which are all found in southern Africa, in Angola, Botswana, Namibia and South Africa. The species of most interest for their appetite suppressing properties are Hoodia gordonii, Hoodia flava, Hoodia piliferum, Hoodia officinale, Hoodia currorii and Hoodia currori subsp. lugardi. The species always preferred by the Kalahari Bushmen and regarded by them as the most potent appetite suppressor is Hoodia gordonii and this is the species that is usually being referred to whenever the name Hoodia is mentioned. It is not as widespread as some of the other Hoodia species and is found almost entirely in South Africa and Namibia.
Hoodia gordonii plants can grow to a height of 1 metre. In the early stages only a single stem is produced but later the plant starts branching. Mature plants can have as many as 50 branches and weigh as much as 30 kg. Flowers are borne on or near the stem tips and can reach a diameter of 75 mm. The flowers come in an exuberant range of colours and have a very distinctive smell, commonly described as carrion-like or similar to rotting meat. The advantage of the putrid smell is that it attracts flies which pollinate the plant.
The natives of the Kalahari know the Hoodia gordonii as Xhoba or Ghaap and it has been important in their culture for many thousands of years, to stave off hunger, to serve as a source of water and also to provide medicinal benefits, the plant being traditionally used by the Bushmen as a medicine to help with a wide range of ailments. Today people all over the world know about the Xhoba or Ghaap and like the Bushmen have for so long they have come to prize it for its appetite suppressing quality. However, the fame and popularity of the plant today has unfortunately threatened its existence, as the demand for Hoodia gordonii in the world today is currently far outstripping its supply.
To remedy this situation, all Hoodia plants including Hoodia gordonii have been made protected species in the countries of southern Africa. In South Africa for example, this means that no one can harvest, transport or trade any Hoodia material without a government permit. Furthermore, all Hoodia plants have been recognised as protected species by CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. This means that no one can trade internationally in any Hoodia material without an export permit being issued by the government of the exporting country, this meaning that the importer as well as the exporter must ensure that an export permit has been issued. CITES also stipulates that an export permit cannot be issued by a government unless the trade can be shown not to have a detrimental effect on the species in question.
These measures are being enforced vigorously by the countries of southern Africa and therefore are likely to afford Hoodia gordonii and the other Hoodia species the protection they need to remain a viable and sustainable resource.