Ragwort varies.
Nineteen species of the Ragwort genus, Senecio, occur in the wild in Britain
https://www.buglife.org.uk/sit...
(different buglife)
Two pics, one of a young plant in June 2012 which had reddish stems, it was growing on stones with sand underneath. The mature plant at end of January. Yes, they made Ragwort flowers.
More young plants from June and July.