The British Horse Society's Scottish website contains a false claim about the law.
Ragwort is classified as an injurious weed under the Weeds Act 1959. This means it is an offence to allow ragwort to spread on any land.
This is not true! It is most clearly not an offence to allow ragwort to spread on any land. You may be ordered to control it but in he absence of an order no offence is committed. This is not the first time that the British Horse Society have issued questionable information. There were many complaints to the ASA about companies who were repeating the dodgy figures the BHS had been issuing on horse deaths. The companies had to remove those statistics from their websites as they could not substantiate the claims.
What is more the BHS were informed of this problem on their website rather publicly several days ago and haven't changed it
This matter is also commented on here in this webpage about Ragwort Awareness Week.