Duke University researchers noted some varieties of junipers are rapidly spreading in water-starved regions of the western United States.

"The take-home message is that junipers are the most drought-resistant group that has ever been studied," said Professor Robert Jackson. "We examined 14 species from the U.S. and Caribbean, and they're all relatively drought-resistant -- even ones in the mountains of Jamaica that get hundreds of inches of rain a year."

The research, which included graduate student Cynthia Willson and Duke Associate Professor Paul Manos, appears in the American Journal of Botany.