The scientists behind the discovery say this highlights a lack of proper monitoring and control of GM crops in the United States.
US farmers have dramatically increased their use of GM crops since the plants were introduced in the early 1990s. Last year, nearly half the world's transgenic crops were grown in US soil — Brazil, the world's second heaviest user, grew just 16%. GM crops have broken free from cultivated land in several countries, including Canada, the United Kingdom and Japan, but they have not previously been found in uncultivated land in the United States.
"The extent of the escape is unprecedented," says Cynthia Sagers, an ecologist at the University of Arkansas in Fayetteville, who led the research team that found the canola (Brassica napus, also known as rapeseed).