There is a common misleading statement that ragwort is an "injurious weed" so it is dangerous.
The confusion here comes from the use of some rather peculiar terminology in the Weeds Act 1959.
It used the word "Injurious" to describe a range of weeds only one of which is actually poisonous to a serious degree. (Almost everything is poisonous in the right amount, even water.
The author of this site actually knows someone who nearly died from drinking too much water.). In the 1920s There is confusion in many people's minds with the word "Injury".
It is perfectly understandable that to many people the word , injurious, seems like it really ought to mean “causing injury” in the actual modern sense of a physical wound or harm to someone’s or an animal’s health. It is important to realise that assumption is wrong, and going on from there, understanding why gets us to a position which reveals something important about what Parliament actually really intended when it listed ragwort as one of the “injurious weeds” in the Weeds Act 1959.
Just to start here with a short explanation of Latin grammar. It is a bit complex but all we are really saying is that Latin puts endings on the nouns to change their meaning. We are going to discuss 1920s language and legal literature. In 1920 the majority of MPs were privately educated; even as late as the post-war period after 1945, posh schools like Eton and Harrow made Latin a compulsory subject. The author of this website is a complete "pleb" , most of his ancestors were Welsh coal miners, but his local comprehensive school offered a single Latin class, restricted to the brightest pupils only, and he went on to study it further as an adult just for fun. Yes it is complicated but that is the fun of it, just like this website. It is essentially the same kind of detailed intellectual endeavour.
Latin puts endings on the words that change their meaning. This is just an illustration so that you get the general idea so don't let it baffle you. It is just there for clarity to explain the point generally. The nominative of a word is its dictionary form. For example, the Latin word mensa means table, a table, or the table, as Latin has no word for "a" or "the". The nominative is the root form , mensa est means "it is a table". Then you have the accusative, like ego video mensam, which means "I see a table". The genitive of a noun describes possession, like words that have an apostrophe S in English, such as “John's car,” or to put it another way, “the car of John.” In this case the Latin word would be mensae. Latin words have several ways to form the genitive, and there are a set of other endings in Latin for other forms of the noun. We use the genitive form in dictionaries alongside the nominative or root form because it also gives you information as to which of the several patterns that particular noun belongs to, and in this case it fortuitously gives information to illustrate sound changes across the timeline of the development of the Latin language.
The word , injurious, in fact traces back to the Latin noun , ius, (genitive , iuris, ), which just happens to be one of the most important words in the entire system of Roman legal vocabulary, which informs so much of present day English legal vocabulary too
. , Ius, meant a legal right, a just entitlement, the law itself, and the place where justice was administered , that is to say, the court. From , ius, came , iustitia, (justice), , iustus, (just, lawful), , iurare, (to swear an oath), and there is a whole family of English words that have come to be built on the stem , jur-, and , just-, : justice, jury, jurisprudence, judicial, adjudicate.
The negative form of the noun was , iniuria, , which is simply formed by adding the prefix , in-, (meaning “not” or “against”) to , ius, . , Iniuria, therefore meant a wrong done against someone's legal rights: an injustice, an unlawful act, a violation of what was properly due. This fact of meaning is confirmed by every single major Latin dictionary. Lewis and Short’s , Latin Dictionary, defines , iniuria, as “a wrong, injustice, injury to rights.”(Lewis and Short, 1879) The Oxford Latin Dictionary (Glare, 1982) gives the primary sense as “an act contrary to right or justice.” There is a good example of this where the famously acclaimed Roman writer Cicero ,an aclaimed orator and law make,r or to put it technically a jurist Cicero (Cicero, 44 BC) used the famous maxim , summum ius, summa iniuria, ,. which means “the strictest law is the greatest injustice,” and it is clear that this is where , iniuria, plainly means a wrong done to someone's legitimate interests, and not a physical wound.
There is an interesting phonological development, the devlopment the sounds of a langauge, in the history of the Latin language here, and it explains why the connection between , ius, and , injurious, is not so clearly and immediately obvious to the eye of an English speaker. In the archaic form of Latin, before about 350 BC, the word now written as , ius, was pronounced and even sometimes written , ious, . The stem of its genitive case (, iuris, ) preserves evidence of an earlier , iousis, or similar form.
The change that happened between archaic and classical Latin was a regular sound change called rhotacism: an , s, sound positioned between two vowels shifted to , r, . This happened systematically across the whole range of Latin words. For example, the word for , flower, is , flos, in the nominative is the root form in the dictiouaries but , floris, in the genitive, where the , r, replaces an earlier , s, that was caught between two vowels. In another example, the word for , sister, in Latin, , soror, , derives from an older , *swesor, , which is known to be preserved in related languages. THose famioloar nwth other European Languasges will notice the German Schwester is similar and by extenision our own Elglish sister. By the time of the classical period of the Latin that is familiar to most people rhotacism was complete and it had become frozen into the grammar, and this is why , ius, has the genitive , iuris, , as the , r, is the old , s, in its intervocalic (between two vowels) position.
The relevance of this for the subject of weeds legislation and law is that , iniurius, , which is the Latin adjective that gives us , injurious, , was as we can see from the sound changes built on the stem , iur-, , which is simply , ius, with the rhotacism sound change applied. It is clear then that the word is therefore really transparently , in-, + , ius, : “against rights,” “contrary to justice,” “wrongful.” It really has nothing to do with physical injury in its origin. Physical injury in the sense of a wound is, we can see, a secondary meaning that developed later just because wrongs done to persons were a subset of the broader category of meanings of , iniuria, .
The Etymonline dictionary says that (Harper, 2026) that , injury, entered English in the late 14th century via Anglo-French , injurie, , meaning “wrongful action,” from Latin , iniuria, meaning “wrong, injustice, insult, unlawful violence.” The physical sense of “wound” that we know today is a later narrowing of the orihinal meaning of a word that originally meant any wrong done to a person’s rights or interests.
The Oxford English Dictionary, which is the accepted definitive dictionary of the English language, gives the primary definition of , injurious, accordingly as: “wrongful; hurtful or prejudicial to the rights of another.” Physical harm appears as a later, derived sense.(OED, 2026)
At this point in the discussion we come to the first of the laws. When the Agriculture Act 1920 introduced the phrase “injurious weeds” into yje law for the first time, it was clearly, as we can see from the speeches in Parliament, using , injurious, in precisely this primary sense: harmful to the interests of agriculture and those with rights in agricultural land. The same Act uses “injuriously affect the interests of persons connected with the land” as a legal test in a neighbouring clause, which makes the meaning really unmistakeable. Parliament was not saying the weeds were toxic or dangerous to health. It was obviously saying they were harmful to agricultural interests.
This reading then is further confirmed by the fact that four of the five weeds listed in the Weeds Act 1959 are not poisonous in any real sense . Spear thistle, creeping thistle, curled dock and broad-leaved dock are actually plants that you will find listed in foraging books for wild plants as safe for human consumption. If “injurious” meant “toxic” or “poisonous,” their inclusion in thew law would make no sense in anywayb shape or form.. It is absolutely clear that the word meant what it has always meant in legal and parliamentary language: prejudicial to the rights and interests of those who depend on the land, and no other meaning.
There is a whole elaborate structure of English law and legal terminology built on , iniuria, , including the tort of , injurious falsehood, , which protects economic and business interests, and we have legal judgements that show that this has been repeatedly confirmed by the courts as having nothing to do with physical harm. The UK Supreme Court confirmed as recently as 2024, in the case of , George v Cannell, , ([2024] UKSC 19) that “injurious” in the legal context of injurious falsehood refers throughout its history exclusively to economic interests, not bodily harm.
So it is really clear we must conclude from all of the linguistic and legal evidence that to call ragwort dangerous on the grounds that it is an “injurious weed” is to mistake a 2,000-year-old legal term about harm to interests , in this case the interests of agriculture in 1920 (Agriculture Act 1920, s.4) for a description of actual physical toxicity. The words of the statute do not have that meaning, and it is absolutely clear that they never did.
It is very clear that parliament meant that meaning of harmful or prejudicial to the interests of agriculture because of the language used when it was discussed. The Weeds Act was a consolidation act that replaced earlier legislation and was not subject to discussion in parliament but, as mentioned above, the words "injurious weed" were first introduced in an amendment to the Corn Production Act 1917 which was debated as part of the Agriculture Act 1920 on the 3rd November 1920. There are many uses of the words "injurious" and "injuriously" during the debate. All of them have the "harmful/prejudicial to interests" meaning including this from James Gardiner then MP for Kinross and Western Perthshire, who attendded a posh private fee paying school
"Every agricultural committee I know has intimate knowledge of agriculture and an intimate knowledge of the district in which control is to be exercised. They are, therefore, well able to ensure that nothing injurious to the cultivation or the country results from the orders they give. "
See also: Injurious weeds and the law and the index of parliamentary usage of "injurious" by year.