New Species Of Tumbleweed Spreading Across Western US

By Andrew Bernier
Published: Monday, April 18, 2016 - 8:27am
Updated: Monday, April 18, 2016 - 3:17pm
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(Photo by Andrew Bernier - KJZZ)
A tumbleweed blocks the roadway in the Phoenix area.

The tumbleweed, an iconic image of the West, is not from the West at all. Now new research suggests not only has a new species of the potentially dangerous plant emerged, but is spreading quickly.

Known as Russian thistle, the tumbleweed has crossbred with another tumbling species from Australia or South Africa. Called Salsola ryanii, the new species contains all 54 chromosomes from its parents, a majority from the rounder and better tumbling Russian thistle.

Researcher Shana Welles said along with shape, other key characteristics identify S. ryanii.

“The fruit are dispersed by that tumbling assisted by wind and so they’re a very small seed surrounded by a winged fruit and the wings look slightly different and that is the characteristics I use to tell these things apart,” said Welles.

Welles also said S. rayanii emerged in California's Central Valley and is spreading faster than other tumbleweeds. She said it’s prevalent in habitats disturbed by humans and can cause damage to vehicles and agriculture. It also can be a wildfire threat.

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