[Cal-IPC] 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? (contributed by Mary Ann Machi)

[Wikipedia] Native to deserts of N. Africa and the Middle East: Brassica tournefortii is a species of plant known by the common names Asian mustard,[1] pale cabbage,[2] African mustard, and Sahara mustard, and is well known as an invasive species, especially in California. 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] The plant disperses easily at the first hint of rain. When the seed coats are moistened they form a gel and become very sticky and readily adhere to people, animals, and objects. Seeds easily take hold along roadsides and arid desert lands, especially in disturbed habitats. The plant disperses 750 to 9000 seeds which stay viable for several years in soil, contributing to its status as an invasive species.[4][5] (contributed by Mary Ann Machi)