The Possibilities to use Euphorbia Tirucalli as an Energy and Rubber Crop
Euphorbia Tirucalli has been used as a source for natural rubber at different times in history, especially in southern Africa. The latex resin content is too high to guarantee a good quality product and economic production has never taken off as some had hoped. The fact that the plant is very well adapted to arid and semi arid conditions and can be grown on marginal waste lands makes it a potential energy crop which can be turned into biogas without too much investment in costly technology. The first results obtained in the laboratory and infield conditions (Senegal) are very promising. The latex contains a number of interesting triterpenes which have a very high energy content and could be used in fuel production. Most of these applications have been tested or used in Africa and can offer long-term solutions for old problems, particularly in the case of renewable energy through biomass fermentation.
This article reviews the traditional uses ofE. tirucalli. This succulent latex plant, although originating from southern Africa, is now growing as a hedge plant in tropical and subtropical regions all over the world. Its special chemical properties have induced people to use it as a source of poison against bacteria, amoebas, nematodes, insects,fish, birds and mammals. Its medicinal use has also been recorded in a wide variety of settings. In a few cases, the latex has been used for the production of varnish and paint.
The Namib desert is reportedly the oldest desert in the world. It consists of a number of very distinct ecosystems, six of which are dealt with in this text. Among them are the sand dune, the dry river bed and the domed inselbergs vegetation. The importance of fog water absorption for the Namib flora is discussed. Two important and noteworthy endemic plant species, i.e. Welwitschia mirabilis and Acanthosicyos horrida are treated extensively, because of their great interest for plant physiology and ethnobotany, resp. Special attention is given to the imponance of the CAM photosynthetic system for Namib desert plant survival. Where possible the ethnobotanic importance of the species is discussed.