2. Amaranthus

Amaranthus is a weed that could be grown as a biofuel crop.

Also known as pigweed, Amaranthus is a highly competitive, classified noxious weed that proves how good bad can be. The pesky little devil has garnered praises from researchers at the University of New Mexico for its ideal traits as a biofuel crop including drought tolerance, high rate of photosynthesis, and resistance to disease and pests.

Image: Just chaos on flickr.com.