Erysimum is a plant in the mustard (Brassicaceae) family, and the Western Wallflower (Erysimum capitatum) is the most common of the dozen native North American Erysimum species. It grows in all life zones in Colorado, from the plains all the way up to alpine areas.
Western Wallflower can be found in a wide variety of colors, from yellow to orange to red-orange or, rarely, purplish-maroon. I’ve seen the purplish color on only one occasion, just above treeline up on Mount Evans (see below).
American Indians used dried leaves or seeds of wallflower to make a tea for stomach cramps. An infusion of the whole plant can be used externally for muscle aches. Wallflowers are also important sources of food for wildlife, including the caterpillars of a number of butterfly and moth species.