Rue, which belongs to the Rutaceae family, is a paradoxical plant: medicinal, spicy, but also toxic; aromatic, but according to some unpleasantly smelly; naturally insecticidal but also a healthy food for some butterflies; soothing for bruises, yet can cause serious skin irritation in sensitive persons. As far back as the Middle Ages the manual 'Tacuinum Sanitatis' claimed that it increased sperm in men yet at the same time reduced the desire for coitus! The Swedish botanist and physician Carl Linnaeus (23rd May 1707 - 10th January 1778) identified nine species of rue in the genus; nowadays ten are recognised. Rue plants are thought to have spread from Europe to many countries around the world, including as far as North, Central and South America, southern Africa, China, India and Asia. Rue is the national plant of Lithuania.
According to Prof. dr. Toni Nikolić, from the Faculty of Science, University of Zagreb, author of the 'Flora Croatica' Database, three species grow in Croatia: ruta angustifolia Pers. (vernacular name: narrow-fringed rue), ruta chalepensis (fringed rue, Sicilian rue) and ruta graveolens (ruta divaricata Ten., common rue, herb-of-grace). 'Graveolens' is Latin for 'strong-smelling'. According to the listing of 'Useful Plants' in the Flora Croatica Database, ruta graveolens can have a role in medicines, food additives, vertebrate poisons, materials and 'social uses'.
Ruta graveolens blooms from June to August. The flower is not fringed, it has no cilia, and the petal margin is toothed. In ruta angustifolia, the flowering leaves are as wide as the stems and the plant is glandular and hairy in the upper part, while in ruta chalepensis, which blooms from April to June, the petal margin is long and ciliate, the flowering leaves are much wider than the stems (especially the lower ones) and the plant is bare. (Toni Nikolić, 'Flora croatica' Volume 3, p.560, Volume 4 p.591)
These three endemic species, which are protected, are spread all over the Adriatic coast and are also found, but very rarely, in northeastern Croatia. According to expert recommendations for the sustainable harvesting of wild native species published in 2023 by the Ministry of Economy (Ministarstvo gospodarstva,. Gambiroza et al, text in Croatian), people can harvest up to 200 kg of ruta graveolens annually, but only the upper part of the plant, not the root. Ruta chalepensis is not recommended for harvesting, while ruta angustifolia is not listed. Experts say that "Rue's homeland is the northeastern Mediterranean (Illyrian-Apennine species), from where the Benedictines spread it across the Alps to Central Europe, where it also grows in country gardens." (Kovačić, Nikolić et al. 2008, p. 301). Of these three species in Croatia, ruta graveolens is the most frequently mentioned.
RUE AS MEDICINE
Throughout history rue has been used for an extremely wide range of purposes, especially as medicine. Applied extrenally or used as a tonic to swallow or chew, various parts of the different types of rue are said to provide benefits for many different kinds of maladies, including high blood pressure, bronchitis, epilepsy, multiple sclerosis, Bell's palsy, headaches, dizziness, vertigo, dementia, eye strain, poor eyesight, ear pain, digestive, chest and menstrual disorders, gum bacteria, eczema, sciatica, arthritis and muscular pains. Rue has also been used as an antidote to poisoning and protection against infectious diseases. In English law courts it was an old custom to put sprigs of rue around the premises and give the judge a bouquet of aromatic plants including rue as a preventive, because so many criminals were sick due to bad prison conditions. In some countries, rue is still said to provide protection against snake venom.
Rue is still used as a medicine in homeopathy and herbal medical traditions such as Chinese medicine and Ayurveda, Unani and Siddha in India. Medicines are made from the leaves and flowering plants, without the roots, and are used in the form of powder, tea, liquid extract and as a tincture.
In Croatia and the wider region, where here and there the old traditions of herbal medicine are preserved, rue is still used and even some recipes have been preserved in written form. For example, S.M. Ljubica Bernardica Kovač gives details about rue tea for regulating menstruation in her book 'Medicinal herbs - a gift from God's hand'. In the book 'Domestic medicinal plants', doctor Katja Toplak Galle gives a recipe for rue tea that should not be used without medical supervision, and another recipe for a tea mixture that mildly stimulates monthly bleeding and can be drunk without supervision.
As rue is credited with so many beneficial effects, it is not surprising that its active ingredients are the subject of intensive research, seeking possible use in medicinal drugs. Studies on ruta graveolens in particular have shown promising results for its antibacterial and anti-inflammatory effects. There are also studies showing good effects against cancer, viruses and parasites; as an antioxidant; as a contraceptive and a fertility regulator; effects on the nervous system have been documented as well.
BEWARE, RUE CAN CAUSE HARM!
Alongside rue's many possible good effects, it can have toxic side effects, so it should not be used as a cure-all or without medical supervision. Known possible adverse effects, especially for ruta graveolens, include an irritating skin rash with blisters called photosensitive dermatitis, caused when someone with skin sensitivity handles rue under sunshine. Because of the risk of causing bleeding in the uterus, rue should not be used or handled during pregnancy. There have been reports that rue can cause heart problems and severe toxic reactions in the liver and kidneys. (In traditional Chinese medicine, R. graveolens belongs to the lung, kidney, liver, and heart meridians.) Other recorded unwanted side-effects include dizziness, insomnia, hallucinations, depression, vomiting and stomach cramps.
As a general precaution, only use medicines based on rue under medical supervision.
RUE FOR FOOD AND DRINKS
Since ancient times, rue has been used as food and spice, in small quantities. Every part of the plant was used in fresh and dry forms. To this day, rue is still used in food in some countries, especially in Ethiopia, where fresh rue leaves are used to add flavour to coffee and in a mixed herb spice called 'berbere'. In Italy, it is still used in traditional recipes for tomato sauces, along with olives and capers.
In Italy and Dalmatia, rue it is still used as a flavouring in local brandy, called travarica in Croatian (the general term for herb-flavoured liqueurs) and more specifically grappa con ruta in Italian. One method is to put a sprig of rue in the bottle of liqueur where it stays for about 40 days, until it has turned completely pale, when the sprig is removed. More rarely, travarica is made by adding rue with other medicinal plants (usually fennel, sage, immortelle and dried bramble fruits) during distillation to produce a yellowish brandy.
RUE IN SPIRITUAL BELIEFS
An old custom on Hvar is to put rue in a bouquet that the priest blesses during Mass on Palm Sunday. Jasenka Bunčuga, also from Jelsa, believes that rue is put in a bouquet just for its scent. However, since ancient times, rue has also had symbolic spiritual significance. In the Middle Ages, Catholic priests used a sprig of rue to bless the regiment by sprinkling it with holy water. An old tradition states that ruta is effective against witches, evil spirits and as an antidote against spells and curses, and it is possible that in some countries it is still used for these purposes.
Related to its use for stimulating and improving sight was the belief that rue could lead a person to clairvoyance. For a while, some believed that rue not only improves eyesight but also strengthens creativity: it is said that Michelangelo and Leonardo da Vinci used to eat a small amount of rue leaves regularly for this purpose.
In Lithuania, Ukraine and other countries, rue is a symbol of a woman's virginity, which is why it is customary for brides to wear rue in a bouquet or on their wedding dress.
RUE AS INSECTICIDE
In the garden, rue can have different roles. As an insecticide, it can protect plants such as roses, raspberries, strawberries and figs from pests when planted near them. In the home, dry rue leaves are a deterrent against moths, and rue decoction can be used to destroy fly larvae, lice and fleas. Despite being a natural insecticide, rue leaves are a healthy food for butterfly caterpillars, especially the Swallowtails (papilio machaon - Old World Swallowtail, and papilio xuthus - Asian Swallowtail). Just as mice and rats hate the smell of peppermint and run away from it, so cats hate the smell of rue, making it an effective deterrent in the garden or in the home if you don't want cats on your property.
RUE IN COSMETICS
Rue extract and the oil from rue leaves are used in perfumes, soaps and in some cosmetics. There is little official control of cosmetics and their ingredients, and much concern about potential allergens which might be contained in them. There are efforts to improve safety in cosmetic products. For instance, in 2001, the European Commission's Scientific Committee on Cosmetic and Non-Food-Products intended for Consumers (SCCNFP) compiled an 'Initial List of Perfumery Materials Which Must Not Form Part of Cosmetic Products Except Subject to the Restrictions and Conditions Laid Down': Rue graveolens was included in section 6, which decreed: "May be used in cosmetic products, provided that the total concentration of furocoumarin-like substances in the finished cosmetic product do not exceed 1ppm". The European Commission's 'Regulation (EC) No 1223/2009 of the European Parliament and of the Council', updated in 2024, set out definitions and safety measures designed to establish come control over the propducts offered on the market. Most often, cosmetic products based on plants are sold with little factual information about their constituents, what they do and their possible side-effects.
CONCLUSION
Plants in the rutaceae family are truly wondrous! But, be warned, they should be used with due caution...
© Vivian Grisogono and Mirko Crnčević, 2022 / 2025.
A version of this article was published in the magazine 'Dobra kob' in 2022.
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Izvori - (Sources in Croatian):
Stručna podloga za sakupljanje zavičajnih divljih vrsta 2024. - 2026.
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