By Angela Hind
BBC Radio 4's Jatropha, the Wonder Plant
There is a bush which has grown across the Americas, Africa and Asia for centuries.
Could jatropha solve India's energy problems? (All pictures copyright D1 Oils plc)
It has been used to make soap and candles, or as a remedy for constipation, high fevers and even malaria.
It is also highly toxic. Just four seeds from its plum-sized fruit is enough to kill, while the milky sap from its bark can stain the skin and irritate it for days.
But the wild jatropha bush - spread across the world from Central America by Portuguese settlers in the 16th century - is now being seen as one solution to the world's desperate search for new sources of energy.
Energy giant BP has just announced it is investing almost £32m in a jatropha joint venture with UK biofuels firm D1 Oils.
India is leading the way when it comes to cultivating jatropha on an industrial scale.
"There is no doubt about it," says Sanju Khan, a site manager for D1 Oils.
"Those who are working with jatropha, are working with the new generation crop, developing a crop from a wild plant - which is hugely exciting."
Although Indians have known about jatropha's more day-to-day uses, and its dangers, for years, the interest now is in its potential to transform the lives of millions of poverty-stricken farmers who are struggling to survive.
The key is in growing jatropha to be used as a biofuel. Once dried out and crushed, these poisonous seeds yield oil which can be burned in almost any diesel engine - with no modification.
With the impacts of global warming becoming ever more apparent, countries all over the world are seeking out alternatives to fossil fuels.
The seeds are poisonous - but with rich energy potential
Biofuel plants like jatropha absorb carbon-dioxide while they are growing, effectively cancelling out the carbon dioxide they release when they burn.
What's more, they could allow developing countries like India - where more than a million new cars were sold last year - to be self-sufficient rather than depending on oil and gas imports in a politically unstable world.
India invests more than $300m a year in researching biofuels - more than many developed nations. - and Jatropha is just one of a number of possible biofuel plants.
But the bush's attraction lies in the fact that it can grow anywhere, even in the poorest soil, needs very little water to survive and will yield seeds for more than half a century.
Even jatropha's keenest supporters acknowledge that there remains much work to be done to find out which varieties of jatropha will thrive best in a whole range of climatic conditions.
But the most optimistic assessments suggest that one day, as much as half India's 63 million hectares of wasteland could be suitable for the plant.
Already in India, 11 million hectares have been earmarked for jatropha growing.
Some see a danger that in a country where subsistence farming - growing food to eat - is still a widespread activity, jatropha could replace much-needed food crops, turning India into a monoculture.
The Indian government believes not. Its plans call for cutting down conventional diesel use over the next six years by blending the fuel with 13 million tonnes of biodiesel.
That would be enough to power half a million cars to drive the length of India. With jatropha, officials believe that might be possible.
Jatropha's proponents say its oil can easily be blended with diesel
Moreover, it might help India become a leading world producer of biodiesel - although that would depend on whether India's farmers could grow enough for both domestic use and for export.
Jatropha's proponents have no doubt that the potential is there.
The European Union, for instance, wants 5% of all fuel sold for use in transport to be biofuels by the end of this decade.
D1 Oils chairman Lord Oxburgh believes that jatropha will be part of this.
When does he think we will be using jatropha biodiesel in our cars?
"In two years," he says - just in time to meet the EU's target.
Jatropha the wonder plant is on BBC Radio 4 at 2100 BST on Monday 9 July, then online for seven days at Radio 4's Listen again page.