SoylentNews

The tumbleweed, an iconic image of America’s West, is actually made up of several species, all of which came to the United States in the late 19th century. The newest of those is Salsola ryanii, a genetic hybrid of two existing tumbleweed species.

[...] In drought conditions, tumbleweeds can help spread wildfires and can also clog streams and drainage ditches, leading U.S. officials to import tumbleweed-killing viruses from Russia to control their spread.