New Tumbleweed Species Rapidly Expanding Range

RIVERSIDE, Calif. (www.ucr.edu) — Two invasive species of tumbleweed have hybridized to create a new species of tumbleweed that University of California, Riverside researchers found has dramatically expanded its geographic range in California in just a decade.

The UC Riverside researchers believe Salsola ryanii is likely to become an important invasive species that could spread beyond California to other states.

“Given how quickly it has spread, this species has the potential to be a problematic invasive,” said Shana R. Welles, who is currently a post-doctoral fellow at the University of Arizona but did the tumbleweed research as a graduate student at UC Riverside. “We want to make sure people know that and try to manage this species when it still had a relatively narrow range.”

Welles outlined the findings in a just-published paper co-authored by her Ph.D. advisor, Norman C. Ellstrand, a professor of genetics and a member of UC Riverside’s Institute for Integrative Genome Biology. The paper, “Rapid range expansion of a newly formed allopolyploid weed in the genus Salsola,”was published in the American Journal of Botany.

The new species of tumbleweed (Salsola ryanii) was first documented by California Department of Food and Agriculture scientists in 2002. Surveying throughout California, those scientists found the species in two areas of the state’s Central Valley in 2002. It was also documented by a wider group of scientists in a third area of the Central Valley in 2009.

The UC Riverside researchers did their field work in 2012, collecting tumbleweed from 53 sites throughout California. They found the new species at 15 of those sites. They found it throughout the Central Valley, but also in coastal areas around San Francisco and as far south as the Ventura area.

The results strongly contradict predictions in earlier studies that Salsola ryanii would not likely become invasive=read more=https://ucrtoday.ucr.edu/35966