[Cal-IPC] Habitat, Ecological impact: Brassica tournefortii (Saharan mustard or African mustard) is a winter annual (family Brassicaceae) found in deserts, desert dunes, and coastal scrub, including the San Joaquin Valley, Sonoran and Mojave Deserts, and southwestern region of California. Saharan mustard readily invades newly burned areas, and is known to increase fire frequency and fuel load. Increased fire frequency can cause scrub habitats to convert to grasslands because the native shrubs are not adapted to recurrent fires. The high biomass of Saharan mustard, along with frequent fires, may deplete soils of important nutrients, making native habitat recovery more difficult. Cal-IPC Rating: High (link added by Mary Ann Machi)

[Wikipedia] N. Africa & Middle East Native: This mustard is native to the deserts of North Africa and the Middle East. It became notorious during the twentieth century after it invaded the deserts of the United States and Mexico. Recently it has become an abundant weed of low deserts including the Sonoran and Mojave Deserts, plus the desert valleys such as the Coachella and Imperial Valleys of southern California.[3] T (link added by Mary Ann Machi)