Helianthus ciliaris is a species of sunflower known by the common names Texas blueweed and yerba parda. Helianthus ciliaris grows in much of the south-central and southwestern United States (from Texas north to Kansas and west to California) and northern Mexico (from Tamaulipas west to Sonora and south to Durango and San Luis Potosí), but it can be found elsewhere in North America where it is an introduced species and often a noxious weed. It is weedy even in much of its native range, growing readily in disturbed areas, on cultivated land, and along the roadside. It grows well in moist areas such as drainage ditches.