[JimRed]

Why not something useless that grows aggressively with minimal or no care? Kudzu comes to mind, or goldenrod or endless other weeds suited to their particular niches?

[thackney]

Why not something useless that grows aggressively with minimal or no care? Kudzu comes to mind, or goldenrod or endless other weeds suited to their particular niches?

To be economic, the plant needs to produce some significant amount of sugars. Converting cellulose to ethanol has been a dream for some for quite a while, but the economics still make it a losing proposition unless an economic enzyme is found that can be produced in large quantities to break it down.