What would you call a plant that may be mankind's next great source of renewable biofuels?

That can leech the noxious chemicals out of contaminated soils?

That is an essential component of Chinese traditional medicines; a potential control drug for an alcoholic's cravings; a plant whose starch makes pies and gravies light and delicious; not to mention a plant that can prevent stream banks from eroding, naturally increase the fertility of depleted farmers' fields; can be ground up to produce fine paper and is a beloved by goats as forage?

Super Plant? Saviour Plant? God's Most Favoured Growing Thing?

How about: "The cancer of the vegetative world" or "the plant that ate the South?"

Kudzu covers an old factory in Rockingham, N.C., in this 1999 file photo. (Chuck Burton/Associated Press)

The latter are the demonic catchphrases that have regularly been attached to the super fast-growing kudzu. It is significant to this country because kudzu is regularly trotted out as a belle example of a demonic, invasive species that global warming might be bringing to Canada.

What is interesting is that even as the cancerous kudzu school of thought holds sway in the popular mind, kudzu's potential uses are holding out the promise of the public rehabilitation of a species that has in a little more than half a century been transformed from farmers' saviour to an environmental Satan.

Origins of kudzu

But first some background.

Kudzu was introduced into North America in the Japanese pavilion at the U.S. Centennial Exposition in 1876. People soon were using it to shade porches and courtyards in the Southern U.S., both because of its fast growth and because of its alluring grape-like smell.

At the same time, kudzu was being sold to farmers as an inexpensive forage crop for their animals. In the 1930s, it was pitched to farmers in the South as a cheap and easy way to reduce erosion, particularly in abandoned cotton fields.

By the 1940s kudzu festivals had sprung up in which kudzu queens were being crowned, and a Kudzu Club of America was formed that eventually enrolled 20,000 members.

In the 1950s kudzu's reputation started to become tarnished.

Without the natural diseases and predators that controlled it in the Far East, the vine began to spread like, well, like a plant trying to eat the South. A strand of it could grow 20 metres in a summer. And when it grew to cover an area, next to nothing — not insects, not animals, not other plants — could exist under its sun-blocking canopy.

In 1953 kudzu was removed by the U.S. Department of Agriculture as a plant suitable for use in its agricultural conservation program. In 1962 its planting was restricted to non-developed areas. By 1998 it was official declared a federal noxious weed by the U.S. Congress.

Mixed messages

What is confusing in this is that kudzu has been introduced into southeastern Brazil, Switzerland, Queensland and New South Wales, Australia, but it is only seen as a natural peril in Mississippi, Alabama and Georgia. Indeed, it is not seen as any threat at all in Japan and China where it is indigenous.

What is going on?

A part of the difference is that there appear to be any number of insects and diseases that keep kudzu in check in Asia. Soil conditions are also vital — sandy soil is death to kudzu, as it generally abhors arid conditions.

But it is also true that in the Orient kudzu is used for many things – medicines, foodstuffs, paper, clothing – and so people tend their kudzu fields. That is, they cut them back when they begin getting out of hand, because to them kudzu isn't vegetative cancer, it is a crop that adds to human's welfare when carefully cultivated.

And it can be so for North American if we weren't so demonized by kudzu's sturdy growth.

I arrived at this view after I had a long chat with Rowan Gage, a University of Toronto professor of botany who has been studying kudzu for more than 15 years.

"If you can develop it as a commodity, kudzu can pay for its own control," is his mantra.

For example he is about to propose a study with U.S. colleagues to assess kudzu's effectiveness as a fossil-fuel replacing biofuel. "We have done an analysis which says you could get as much biofuel out of a good kudzu field as out of a good corn field," he tells me.

However, he is even more upbeat about kudzu's long-term food use as a natural thickener for gravy and pies. "It makes soft, silky gravy," he positively swoons. And as to pies, well "they are great."

Image overhaul

What is needed, he says, is a massive rebranding of the so-called cancer of the vegetative world.

"To rehabilitate kudzu you really have to have someone really believes in it, and has hundreds of thousands of dollars to spend," Gage said. "They would push it as this wondrous food from Asia that has become a weed in North America. And you would have this big advertising campaign — you know, kids handing out kudzu packages with recipes on them and kudzu drinks."

What sort of recipes? Well, the Internet already features descriptions of how to make kudzu blossom jelly, rolled kudzu leaves, kudzu fried chicken and apple cider thickened with kudzu.

Added to this is the fine paper that the kudzu starch creates, the studies in soil remediation now underway and that 2005 Harvard study that showed taking an extract of kudzu could halve alcohol consumption by heavy drinkers.

As I said, a massive rebranding — but I also think we have to apply what you might call the "kudzu lesson" to our relations with other invasive species.

Yes, of course we need to try to keep bad things out of the ecosystem, but once they're here we must think just as passionately about what we can do with them. And to make this possible we must be careful about turning invasive species — things which are after all an expression of nature — into monsters whose very existence seems designed to frighten kids of all ages

The kudzu lesson applies to zebra mussels, purple loosestrife and everything else now bearing the mark of an invasive Satan. The kudzu lesson can be boiled down to a mantra: When life gives you kudzus, try to make jellies and biofuels and paper and medicines, and better-than-good gravy of them.