Senecio flaccidus, formerly recorded as Senecio douglasii (in honor of the botanist David Douglas) member of the daisy family and genus Senecio also known as threadleaf ragwort (and threadleaf groundsel, bush senecio, creek senecio, shrubby butterweed, comb butterweed, smooth threadleaf ragwort, Mono ragwort, Douglas ragwort, Douglas groundsel, sand wash groundsel, felty groundsel, old man, yerba cana, squawweed or cenicillo) is a native of the southwestern Great Plains of North America.