Jatropha is a genus of plants, trees, and shrubs native to South America and the Caribbean. An estimated 175 species are placed in this genus. There are a number of uses for Jatropha, ranging from compounds which can be used as vegetable dyes to oils which can be utilized in the production of biofuels. Some alternative fuel advocates have championed Jatropha as a source of potential biodiesel, although there is some evidence to suggest that there are better alternatives.
These plants are in the family Euphorbiaceae. Like other plants in this family, they contain a number of compounds which are toxic, along with a sticky, milk white sap which acts as a skin irritant. Members of the Jatropha genus also have extremely toxic seeds; it only takes three to kill a full-grown adult. Despite the toxicity, some cultures have used parts of Jatropha species in traditional medicine and cooking, and research indicates that some species may contain compounds which are useful medicinally.
In appearance, this genus is very diverse. All of the species have distinctive clusters of small flowers, and they are classified as succulents, with fleshy stems which are designed to endure extreme weather conditions. Some of the plants are low-lying shrubs, while others grow more upright, and they can be bushy to thin. One major advantage for people cultivating Jatropha species is the fact that they thrive in poor soils, and they can endure low water and semi-drought conditions.
Historically, several species have been cultivated as hedges. Jatropha species with compounds which can be used as dyes have been used by several Native American tribes to produce colors such as red and blue, and in Mexico, Jatropha has been used in traditional basketmaking and weaving.
The oil extracted from the seeds can be used in the production of soap and candles, and as a biofuel. Pure oil can be burned in many engines as-is, and it can also be refined. Tests of the oil have shown that it can be used to power trains, planes, and many automobiles. However, because no species have been domesticated, it is difficult to achieve a reliable yield. Jatropha curcus is one of the most promising species, and it can be found under cultivation in many parts of Africa and India.
In addition to being used as a source of biofuel, plants in this genus can also be utilized as biomass in power plants, with the remainder of the plant after pressing for oil being burned for energy. This makes the use of Jatropha highly efficient, as it can be grown in areas where other plants will not thrive, and the whole plant can be used.