Brake grabs an Arundo stalk and walks until it's parallel with the ground. Tiny seeds cascade to the ground, clinging to a visitor's wet shoes.
"You afraid of becoming Johnny donax-seed?" he asks with a chuckle. The seeds are sterile, he says reassuringly.
Brake points to a joint on the stalk where a small sprout or "node" peeks out.
"Each node is a potential plant," he explains. "That makes it easy to propagate."
And that's what gives so many pause.
In the 16 years since Arundo was first identified in California's Sonoma Creek Watershed, Mark Newhouser has developed an attack strategy.
First, workers spray the mature cane with herbicide, then move in with the large flail mowers. If that doesn't do the trick, it's time for chain saws.
"And then you'd still have all of these stumps of cane sticking up everywhere," he says. "You can't even walk through there."
The cost: Up to $25,000 per acre.
To address such concerns in North Carolina, state agriculture officials teamed up with the biofuels center last year to craft a set of "best management practices" for energy crops. Among them are not planting directly adjacent to streams and irrigation canals, and establishing buffer zones of at least 20 feet around production fields.
They are listed as "voluntary." But anyone wishing to do business with Chemtex would have to sign a contract agreeing to certain ground rules, says executive vice president Paolo Carollo. He points out that a $99 million USDA loan guarantee announced this spring also came with certain mitigation measures.
Noting that Chemtex has already made conditional agreements to plant 10,000 acres near Clinton, Carollo points to a factory near Venice, Italy, that, from 1937 to 1962, used Arundo grown on 12,000 nearby acres in the production of fabric, including Rayon.
"And they never had issues of spread," he said in a phone interview from the company's headquarters in the coastal city of Wilmington. When production ceased, he said, those acres were converted back to pasture land.
Attempts to commercialize Arundo donax in other parts of the U.S. have met with limited success.
When a company proposed to use Arundo for power generation in Florida, the state Department of Agriculture and Consumer Services drafted regulations requiring permits for plots larger than 2 acres. Although some permits have been issued, the large-scale project that prompted the regulations never materialized.
And when Portland General Electric decided to convert a power plant from coal to biomass, Oregon state agriculture officials conducted a risk assessment for Arundo. Last year, the state authorized a 400-acre "control area," prohibiting plantings within a mile of water bodies and requiring growers to post a $1 million eradication bond.
In a statement released last March, the Native Plant Society of Oregon accused the state of understating the risks. It cited research suggesting that Arundo's sterile seeds might, through "genetic modification," become fertile.
When Chemtex announced its plans for North Carolina, the Environmental Defense Fund and others petitioned the state to have Arundo declared a noxious weed, and to ban it. Officials expect to make a decision by early next year.
Federal action could take longer.
In January, the EPA gave Arundo preliminary approval under the federal renewable fuel standard program — meaning producers could qualify for valuable carbon credits. When environmental groups complained that the decision was at odds with an executive order aimed at preventing the spread of invasive species, the agency agreed to re-evaluate the crop.
Without the EPA's renewable fuels designation, Arundo would be less profitable to grow. And without Arundo in the mix, says Conlon, "I would be greatly concerned" about the Chemtex project — and the state's grand plans.