5. Castor

Castor, considered a weed in Australia, could be grown as a biofuel crop.

The lovely castor plant is a noxious weed in Australia, introduced in 1803 and firmly establishing itself as a pest in every state except Tasmania. Meanwhile over in Israel, the company Kaiima Bio-Agritech believes that it has found a way to manipulate the chromosomes of biofuel crops to double their yield, with castor showing particular promise – at least in countries where it can be cultivated without overwhelming native species.

Image: pizzodisevo on flickr.com.