It’s the tumbleweed that ate California — or is about to.
A giant weed born of a Russian-Chinese species that bred with one from Australia and South Africa has spawned a monster that is thriving due to climate change and taking over Southern California. New research reveals the secret of its resiliency, as well as the fact that it is here to stay.
While the world obsesses about Russian election meddling and China trade wars, and the U.S. government attempts to recalibrate our country’s status as a melting pot welcoming immigrants from all cultures, nature has unleashed a titanic tumbleweed.
First detected in 2002, Salsola ryanii is a hybrid of two invasive species, according to a report in Newsweek. Salsola tragus originates in Russia and China, and Salsola australis hails from Australia and South Africa and is known in scientific circles as “one of the world’s worst weeds,” as Newsweek put it. That one already lives in 48 U.S. states.
Even regular-sized tumbleweed can overwhelm a town, as residents of Victorville, Calif., learned in 2018 when high winds inundated homes and streets with piles of the weed. A Texas homeowner found himself in similar straits in 2013.
Tumbleweed’s trademark is to detach at the root and seed itself by rolling across the land, thus making it a staple of Westerns.
The newest incarnation has outgrown its parents and shows no signs of abating, according to a new study conducted by researchers at the University of California Riverside.
Growing about 6 feet tall, it is the size of a Volkswagen, as KCBS Radio noted.
A study published this week in the journal AoB Plants, out of Oxford University, showed why. These plants, unlike most other hybrid species, managed to retain two sets of chromosomes from the mother plant and two from the father, rendering the offspring fertile. Multiple sets of chromosomes make these hybrids fertile, UCR said.
In 2016 UCR researchers noted that the hybrid had expanded its territory and was poised to spread to other states.
“Given how quickly it has spread, this species has the potential to be a problematic invasive,” said Shana R. Welles, who conducted the earlier tumbleweed research as a graduate student at UCR, in a statement from that study. “We want to make sure people know that and try to manage this species when it still had a relatively narrow range.”
“Salsola ryanii is a nasty species replacing other nasty species of tumbleweed in the U.S.,” said study co-author Norman Ellstrand, UCR Distinguished Professor of Genetics, in a UCR statement. “It’s healthier than earlier versions, and now we know why.”
