Invasive plants have been a problem in the United States for years. They range from the fast-growing Japanese kudzu, which has smothered more than 3 million hectares, mostly in the South, to the bristly cheatgrass, native to Eurasia and the Mediterranean, which has wreaked havoc on western lands, crowding out other grasses and fueling bigger fires in places like Nevada. Yet scientists have long assumed that native species are more widely distributed than these newcomers, because the natives have had more time to fill in their potential ranges.
Read more of the news story here