Washington ? A plant that flourished in Europe roughly 3,500 years ago could become a major source of biofuel.

Researchers say that camelina, planted on millions of acres of marginal farmland from eastern Washington state to North Dakota, could help power the nation’s drive for cleaner energy.

“This is the most exciting crop I have seen in my 30 some years in this field,” said Steven Guy, a professor at the University of Idaho and a crop-management specialist.

Researchers in Washington state, Oregon and Idaho say the results from test plantings of camelina are encouraging. So far, the only farmers who are interested are in Montana, where more than 50,000 acres of camelina were planted this season. But buzz is spreading.

The story of camelina, though, is about more than just marketing an ancient crop to solve some of today’s problems. It stretches from a Puget Sound biotech firm that’s working to increase camelina yields by up to 50 percent to Capitol Hill, where lobbyists hope to convince Congress to cover camelina under the federal crop-insurance program to reassure skittish farmers.

Camelina supporters say the plant can grow in more arid conditions, doesn’t require extensive use of expensive fertilizers, herbicides and pesticides, and can produce more oil from its seeds than other crops such as canola, by some estimates, for half the price.

“We actually think it might be the next wonder crop,” said Tom Todaro, the chief executive of Targeted Growth, a Seattle biotech firm that’s working to increase camelina yields “radically.” The company hopes to produce enough seed to plant 1 million acres of camelina by 2009.

“I am really excited about it,” said An Hang, a Washington State University research agronomist.