This is a revised edition of a book of the same title published in 1997; it has been fully updated to incorporate the latest research findings of more than 150 medicinal plants, featured in detailed colour photographs, along with species that are related to them. A very large number of scientific publications on South African medicinal plants has appeared since 1997, so that the available information has probably almost doubled. Most of the plant monographs has therefore to be updated substantially and 18 new monographs have been added to this new edition.
Detailed species descriptions include the following information: a description of the plant; the plant parts used; medicinal uses, preparation and dosage; active ingredients and pharmacological effects. In addition, each entry includes a distribution map and a diagram of the chemical structure of the main active ingredient.
Introductory chapters include cultural aspects of healing, methods of collection and storage and methods of preparation and administration, and general description of active ingredients.
There are an estimated 200 000 traditional healers in SA, and up to 60% of South Africans consult these healers. Most elderly folk in rural areas have a knowledge of herbal lore, and function as first-aid healers with family repertoire of herbal remedies.
As the book points out, wild medicinal plant resources are increasingly under threat due to habitat destruction as a result of agricultural, industrial and housing development. The activities of professional herb gatherers and traditional healers thus have an exaggerated impact on the remaining stock of plants. In times past the plants were collected and stored according to traditions and taboos which protected them from over harvesting.
As experienced 'inyanga' will generally seek the guidance of an ancestral spirit befor embarking on a collection trip. The healers supplements this supernatural advice with his own experience of where to collect and how much and this leads to sustainable practices. Modern urbanized healers are less rigorously trained than their forebears and purchase from street markets, providing an economic incentive for the destructive harvesting of medicinal plants. Some rare medicinal plants are being cultivated to reduce pressure on the wild populations.
Looking at an example of the kind of tradition which leads to sustainable harvesting: In Gazankulu, a Shangaan taboo dictates that if the remaining root system of Elephantorrhiza elephantine is not covered after a portion has been removed, the patients treated with it will not recover.
The active ingredients in leaves, roots and bark are often quite different - a particular part may be very toxic while another part is quite harmless. The whole plant is therefore rarely used for medicine. Of the 150 species included in the book, roughly equal number are used primarily for their leaves and/or twigs, their stem bark and their underground parts. Interesting exceptions are the use of wood, seeds, gums, exudates and nectar.
In the index section of the book, the plants are listed according to the ailments they can treat. An important warning is issued pointing out that the book is intended as a scientific overview and not as a medial handbook for self-treatment. Many of the plants described in the book are highly toxic and may coase severe allergic reactins or serious poisoning.
Some of the plants such as Hoodia gordonii (Ghaap) have become the focus of commercial development. The Ghaap or Bitterghaap was traditionally used as a functional food to suppress hunger and thirst and is now being marketed as an appetite suppressant.Mesembryaunthemum tortuosum (Kougoed or Kanna) is a traditional sedative of the Koi-San people and is now being marketed as a stress reliever.
Ben-Erik van Wyk is a professor of Botany at the University of Johannesburg with a research interest in systematic botany and plant utilization. Bosch van Oudtshoorn is a retired professor of pharmacy and a pioneer researcher of the medicinal properties of plants - he has many years experience in the pharmaceutical industry. Nigel Gericke is a medical doctor an expert in the field of ethnobotany in South Africa. He is currently involved in the development of new phytomedicines.