A member of the mustard family, the Western Wallflower ( Erysimum capitatium ) is a brightly colored yellow flower which is quite common across the western United States, including Arizona, Utah and Nevada.. In European countries, the wallflower earned its name from a habit of growing on… you guess it, walls. More specifically stone, masonry or wooden fences. The name was transposed to the American species despite the fact the plants have no preference for walls.
