The genus Amaranthus is a complex taxon with many diverse morphologies within its seventy species. Around the globe, many of the species of Amaranthus provide important nutrition in the form of grains or leafy vegetables; however, characteristics of rapid growth and high seed production have enabled many of the genus members to thrive as alien species. This trait has become inconvenient for humans, who find a significant decline in many cultivated crops invaded by alien species of this genus. A number of herbicides have been used against Pigweeds, including glyphosate and benzoates such as pyrithiobac.