Erysimum hieracifolium; The Hawkweed-leaved Treaclemustard is a common plant around the shores of lake Mývatn. Els on Iceland it is more rare. It is one of only a few yellow-colored mustard-family species readily recognized by its rather tall (about a ½m or more) erect appearance.
It is member of the Cruciferae (mustard) family.