6. Jatropha

Jatropha could be cultivated as a biofuel crop.

The jury is still out on jatropha, which achieved biofuel superstar status a couple of years ago only to see its star tarnished by charges of land grabbing, deforestation, and even biopiracy, including the replacement of food cropland for jatropha cultivation. Lesson learned: whether it’s a food or nonfood crop, biofuel cultivation has to be balanced with regional and global nutrition.

Image: prashantby on flickr.com.