It will be useful now to clarify here the difference between cultivated and wild rue, for there is some confusion in the later tradition. Dioscorides writes of the cultivated or garden rue and the wild rue that grows on mountains together as ‘peganon’. He has a separate entry for the wild rue ‘peganon agrion’ called ‘harmala’, by the Syrians ‘bessara’ and by the Cappodocians ‘moly’. It is sometimes called ‘Syrian rue’ but is the white-flowered harmal Peganum harmala from the Zygophyllaceae (USDA 2010). The fact that these plants of different families are both called wild rue sets up a confusion. For Dioscorides’ peganon agrion or harmal is also used for dim-sightedness but there is no internal use mentioned for either the seed or root. Galen accords with Dioscorides in pointing out that the wild form of rue and harmal are both called ‘wild rue’ but differentiates garden and wild forms by attributing heating and especially drying qualities in the fourth degree to wild rue (a category reserved for agents which can inflame and blister the skin) and in the third degree to garden rue. Mattioli tells us that harmal is also deemed hot and dry in the third degree by Galen, and therefore it cuts thick humours, provokes diuresis and menstruation, and purges phlegm. Is this simply Galenic pharmacological theory or was harmal used internally in this way? It may be good for shoulder pain, according to Galen, but this could perhaps be achieved through topical application. Our later French edition of Mattioli, as well as providing a description of harmala, states that the seed of wild rue (i.e. harmal) prepared and mixed with honey and sesame or almond oil is remarkable in purging melancholy by vomit and also treats epilepsy. It is added that the Arabs regard the seed as intoxicating and makes those who take it sleep long. Modern research has identified that one of the plant’s alkaloids, harmaline, has a monoamine oxidase inhibitory effect, that as an entheogen (a substance that facilitates communion with the supernatural) it has been likened to the South American ayahuasca (which also causes vomiting) and that animal studies show it is an abortifacient and can reduce spermatogenesis. In modern Turkey, the seeds of harmal are hung in a house to protect from the ‘evil eye’ and in Iran an old Zoroastrian ritual is still occasionally carried out in restaurants where diners are exposed to the gaze of strangers whereby the seed capsules and other ingredients are placed on hot charcoals whereupon the seeds explode, releasing a fragrant smoke which is wafted about the diners’ heads as protection.
Latin texts name garden rue ‘ruta sativa’ and wild rue ‘ruta agrestis’ or ‘ruta sylvestris’. Mattioli correctly reads Dioscorides and comments that ruta sylvestris practically covers mount Salvatinus, demonstrating again that the wild peganon is found in mountainous areas. Gerard even includes the hills of Lancashire and Yorkshire as locations in which to find ruta sylvestris, though it is a native of southern Europe, but Parkinson is doubtful of the claim, sure that rue would not survive winter in the Pennines (the fact that Fernie (1897) and Grieve repeat the claim shows that they have read Gerard but not Parkinson on the matter). Mattioli admits that he has not yet seen (in 1554) the plant harmal, although it reportedly grows in the botanic gardens in Padua. He chastises Fuchs in his work called Paradoxes for misreading Ibn Sina on wild rue by assuming that Ibn Sina was discussing harmal when in fact he was following Dioscorides on the wild form of rue. Equally, Mattioli reckons that when the Mauritanians (Arabs of North Africa) speak of ‘armala’ (i.e. an unaspirated form of harmala) they mean the wild form of rue and if Italian apothecaries are following any of their prescriptions, they should prepare wild rue when ‘armala is required. Mattioli makes no comment on the advice of Dioscorides not to use wild rue internally. Dodoens has a separate section for harmal but tells us that the wild form of rue is called ‘harmel’ in the apothecaries’ shops. Turner regards the seeds of wild rue as safe to ingest but unhelpfully calls its root ‘moly of the mountains’ while Gerard falls prey to Fuch’s misunderstanding by suggesting that ‘Harmala’, ‘Harmel’ and ‘Besara’ are simply alternative names for wild rue among the Arabic writers. In the 18th century Miller names the white-flowered harmal ‘wild rue’. Location helps to distinguish the species, although this is unhelpful if the only examples are seen in botanical gardens. Cultivated or garden rue, according to Pliny, loves to grow in open, dry places, especially on clay and needs to be dressed with ashes, but it hates dampness, winter and manure. The wild form is found in mountainous areas, while harmal is a plant of desert regions. Harmal has become an invasive weed since being planted in New Mexico in the late 1920s and has since spread across the salt-desert shrub lands of the western USA, successfully competing with native species because of its drought tolerance.
Despite the confusions over wild rue, Dioscorides’ warnings that eating too much of this wild form can be fatal and handling it can blister the skin are passed down the tradition, from the Arabic writers to the Renaissance authors. Gerard, for instance, affirms that wild rue ‘scor-cheth the face of him that looketh upon it, raising up blisters, wheals, venometh the hands that touch it, and will also infect the face if it be touched before they are clean washed; therefore, it is not to be admitted to meat, or medicine’. Fernie (1897) later quotes the same statement and warns of inflammation of the skin but Grieve omits it and styles rue a topical rubefacient agent without this caution). Bauhin informs us that Guillaume Rondelais (1507-66), physician and botanist at the medical school in Montpellier, used to tell a story about meeting a man on pilgrimage to that city who came across rue on his journey and, having heard that Montpellier was beset by the plague, gathered the herb, placed it in his nostrils and held it in his hand for some time, whence the parts in contact with rue became greatly inflamed.
Rue is ‘among our chief medicinal plants‘ says Pliny, and its extensive uses by ingestion are consistently passed down as far as Culpeper. We have heard of its emme-nogogue action, to which is linked by Galenic pharmacology a diuretic one, although the indication was given by Hippocrates. Pliny, who tells us this and reckons the herb good for the kidneys, then marvels at how some use rue for incontinence of urine, while treatment of strangury is made by the usual internal administration or the application of an oil of rue over the bladder area. Mention has also been made of its ability to antidote the poison of a snake bite. Dioscorides includes not only reptile poisons but all deadly poisons, requiring a dose of one oxybaphon (a volume measurement of nearly 70 mL) of the seed taken in wine. Pliny regards the pounded leaves of any sort of rue in wine a powerful antidote, especially against aconite, mistletoe, poisonous fungi, snake bites, rabid dogs and scorpion and other stings. Apuleius advises the powdered seed drunk in wine and laid on for scorpion stings. Seth cited in Fuchs adds opium to the list of poisons rue antidotes. Pliny notes that weasels about to fight with snakes first protect themselves by eating rue. It is also good for fevers with rigors.
Serapio calls rue ‘the ultimate medicine against the evil of poisons’ and Dodoens, Gerard, Bauhin, Parkinson and Culpeper want it as a remedy against the plague. It was, after all, one of the ingredients of the ‘vinegar of the four thieves’ who robbed the houses of plague victims under the protection of their aromatic repellent. Quincy, Miller and Hill consider it an alexipharmic remedy against the plague or epidemic infections and fevers. Drury (1992) comments that the English courtrooms of today no longer have to contend with the threat of gaol fever (typhus) or the plague from defendants in the dock or from members of the public in the gallery, for which rue was used as a strewing herb as proof against these contagions of the Renaissance and early modern periods. A belief in rue’s ability to combat poison thus has a long history and strong recommendation, since it is a constituent of the famous antidote of Mithridates, King of Pontus. Parkinson informs us that each morning the king, to protect himself against poisoning, would take 20 rue leaves mixed with a little salt, two walnuts and two figs, the whole beaten to a mass and ingested as a daily dose. We know this because, as Fernie (1897) relates, the Roman general Pompey found the formula in the satchel of the conquered king. The formula turns up in the Red Book of the physicians of Myddfai. Culpeper offers particular praise to Mithridates for his researches in physic, dismisses arguments that protection against cold poisons do not afford immunity against hot poisons but recommends instead that Mithridates’ formula, to which Culpeper adds 20 juniper berries, taken in the quantity of a hazel nut, will preserve admirably the health of the body. This is because rue is a herb of the sun in Leo, an alexipharmic like juniper, which by fortifying the heart strengthens resistance to all disease. The herbs must be gathered, however, at the astrologically propitious hour.