Getting to the roots of Sahara mustard invasion in the American Southwest

In 2015, a rural community in southeastern California approached Daniel Winkler and his doctoral advisor, Travis Huxman, for help with an invader that was hurting their local economy. An Old World annual plant called Sahara mustard (Brassica tournefortii) was spreading rapidly through the deserts of the southwestern U.S., carpeting the local Anza-Borrego Desert in spring, and smothering the native wildflowers that draw tourists to the region. Loss of native plants put the animals that depend on them for food and shelter at risk. The mustard was disrupting the entire desert ecosystem.