Before we get into a fight about whether it’s groundsel or ragwort… there are plenty of sources which say they are common names for the same thing e.g. Encyclopaedia Brittanica:
Groundsel, also called ragwort, any of about 1,200 species of annual, biennial, and perennial herbs, shrubs, trees, and climbers constituting the genus Senecio of the family Asteraceae
and Wikipedia
Vernacular names for S. vulgaris in English include old-man-in-the-spring, common groundsel, groundsel, ragwort, grimsel, grinsel, grundsel, simson, birdseed, chickenweed, old-man-of-the-spring, squaw weed, grundy swallow, ground glutton and common butterweed.
Good luck getting a species-specific id!
Groundesl is Senecio vulgaris ragwort is Senecio jacabea