One common myth about ragwort is that it is a “notifiable weed”, This conjures up an image of something really deadly like rabies, a notifiable disease. Of course this plainly isn't true.
This is an extremely common plant and if there were a requirement on anyone to report it the poor authorities would be inundated with reports. Ragwort is an important plant for wildlife.
One of the effects of this and the general unwarranted panic about the plant is lots of reports are made and the authorities think there is a real concern. This myth frequently finds itself repeated by authorities and even wildlife experts. This is having a generally bad effect ecologically as more people are driven to unnecessary controls.
It is not uncommon to see this plant listed alongside Japanese Knotweed and other foreign invaders like Giant Hogweed. These are mentioned under the 1981 Wildlife and Countryside Act where it is prohibited to plant them in the wild, but they are not notifiable either. There is just no such thing as a notifiable weed under UK law.
Of course, despite myths to the contrary ragwort is a native plant
The myth has even been repeated in a parliamentary question and it elicited, for anyone who doubts what is being said on this site, the following response from the relevant minister
“The five weeds covered by the 1959 Act are not "notifiable" as such and there is no obligation to report their presence to anyone. “
See also Ragwort the law.explained