Frank C. Pellett states in his book "American Honey Plants" that  "F.N.
Howes, (Plants and Beekeeping) describes ragwort (Senecio aureus) as
deep yellow in color possessing a strong almost bitter flavor."  The
section on ragwort reports that the various members of the Senecio
family are a common source of bee forage in the United States,
especially in the Southern region.