Rue is a hardy, shrubby and evergreen plant native to Southern Europe. It’s regarded as one of the oldest garden plants in England, but it doesn’t appear naturally in its wild state except for in parts of hilly areas of Yorkshire and Lancashire. Yet, its wild form is much more vehement in smell than the strong, bitter smell of garden plants. Introduced by the Romans, it’s an old fashioned garden plant that was primarily grown for medicinal reasons.
While it’s still used in some countries, it is hardly grown in gardens nowadays. Its medicinal uses aren’t the only reason to have a rue plant in your garden, though. Before we look into the uses and varieties, let’s go through a brief history of rue plants.
Brief History of Rue
Before the medicinal and homely uses of rue were recognized, the plant was first mentioned by Turner in his book Herbal in 1562. Besides being used for medicinal purposes, it was widely associated with spirituality and paranormal entities. It was used by the Greeks, who considered it an anti-magical herb. Later on, it was used as a powerful defense in spells against witches in many parts of Europe.
Moving ahead, in 1625, the popular Neapolitan physician, Piperno, recommended the use of rue for curing vertigo and epilepsy. It was also once used to cure other diseases by wrapping it around the neck of the patient. Moreover, it later came to be used for the preservation of vision and sight, and to make a person’s vision sharper and clearer.
These developments laid the foundations of the extensive medicinal uses that were later uncovered.
Uses of Rue
Rue has an extensive history of use, particularly in medicine, being considered as a protective herb. Prior to flowering, the top shoots of the plant are gathered and used fresh or dry as a home remedy. The primary contents of the plant include alkaloids, furocoumarins, essential oil containing compounds, alcohols, and other compounds.
It was mainly demanded its flavonoids, such as rutin, that is used to strengthen the blood vessels and reduce blood pressure. These flavonoids have been used to treat parasitic worms in the form of anthelmintics. Moreover, they have been used as antispasmodics, hemostatics, anti-inflammatory medications, expectorants, and stimulants.
Rue is believed to be effective in other secondary purposes such as inducing vomiting and releasing gas. It has been taken as an infusion to cure coughs and stomach issues like flatulence, while the juice of the herb has been used to relieve earaches. An infusion of the rue herb has been used to treat problems that arise from strained and tired eyes and is thought to improve vision. Moreover, it was also considered useful in treating diseases associated with the nervous system, such as Bell’s palsy and multiple sclerosis. Not only that, but this plant was also used to overcome vertigo and dizziness.
Rue essential oil, when mixed with water and sugar, is thought to be an effective way to deal with gastrointestinal problems. However, it may act as an acro-narcotic poison if consumed in large amounts. Any treatment involving rue shouldn’t be taken right after meals as it induces vomiting.
While the oil can also serve as an ointment, the leaves have been used to relieve pain occurring from sciatica. To eliminate bacteria, it has been recommended to chew rue leaves. While the saturated and compressed decoction of rue leaves is believed to be useful in the treatment of persistent bronchitis, they have also been used to cure headaches by placing fresh leaves on the forehead.
Today, however, rue is hardly used in developed countries. Yet it’s still considered a major component in traditional Indian medicines such as Unani, Ayurveda, and Siddha, as well as for herbal medicines in other developing countries.
In traditional Indian medicines, the herb serves as an emmenagogue and is used to treat colic, flatulence, and coughs. The leaf of the rue plant is used to treat internal issues like amenorrhea and menorrhea and external illnesses such as bronchitis, sciatica, arthritis, chest muscle pain, and headaches. Also, the oil is used as an anti-epileptic, a rubefacient, and an antispasmodic.
Even though rue plant leaves are bitter and strong in taste, they’re eaten in some parts of the world. However, due to their slight toxicity, they are mostly consumed in small quantities. The leaves of this plant are mostly used as a condiment to add flavor to a variety of foods, while its powder is used for making tea. They’re sometimes used in salads but more often serve as a seasoning, either fresh or dried.
For cooking purposes, rue is most popular in Ethiopia. Its national spice mix, known as berbere, makes use of the rue herb as a component, while the fresh leaves serve as a popular flavoring. Various Ethiopian cuisines make use of rue leaves as well as its dried fruits or rue berries, which have an intense, pungent flavor.
Generally, use of rue for cooking is considered old-fashioned – it was pretty popular about half a century back. Yet, it is particularly preferred by older people as they typically develop a favorable attitude towards bitter taste as they age. If not overused, rue can add outstanding spicy flavor to eggs, meat, and cheese. Hence, you may use rue leaves to enrich the taste of pickled vegetables and vinegar as well as salads.
Besides its popularity in Ethiopia, rue is occasionally used in Italy. Rue leaves excrete essential oils at a quicker pace than the bitter rutin. This means that you can eliminate the bitterness by soaking the fresh leaves in a slightly boiling sauce for a minute or so and then discard them. This will enable you to achieve the maximum flavor, significantly minimizing the bitterness.
Due to its bitterness, rue has also been used to add flavor to liquors. Bitter liquors contain some stomachic, bile-stimulating, and tonic properties that make them beneficial after a rich feast. The Italian brandy, known as Grappa con Ruta, makes use of a small branch of fringed rue per bottle and is highly popular.
Other recipes that make use of rue in various quantities include seafood gumbo, broccoli cheese soup, rue spice cake, endives wrapped in ham, peas with rue, scotch rues, clam chowder, potato soup, cheese-rue casserole, sauerkraut and bean soup, linguini and white clam sauce, seafood au gratin, lentil soup, and Roman-style garlic cheese with rue.
Rue plants are extremely efficient insect repellents, both during its growth and when dried. Ideally, they should be planted near roses and raspberries to protect them from bugs and pests. Sometimes, they’re even useful to keep cats away from plants. Dried rue leaves are helpful in repelling moths as well. Rue is also used to kill fly larvae and lice when blended as a decoction.
The fresh leaves of rue plants are used to extract oil that possesses a strong, distinct odor. This oil is present in the glands distributed all over the plant. It is then used in the production of a wide range of soaps, fragrances and beauty products. Also, the plants are used to create a red dye.
Effects of Overdose and Toxicity
It is important to note that large doses of rue have proved toxic. Plus, pregnant women should never use it. The oil containing compound, methyl nonyl ketone, can adversely affect the uterus. The herb contains abortive properties that would most certainly result in miscarriages and hemorrhaging. Therefore, rue plants should be handled with caution, and the person interacting with them should wear gloves every time they do so.
A substance called furanocoumarin is present in rue juices, which can sensitize your skin to light, causing blisters or dermatitis. It is also responsible for hepatotoxicity. Some issues that can result from mere mild toxicities include sleep disorders, dizziness, fainting, tongue swelling, phototoxicity, mood changes, fatigue, spasms, bradycardia, and clammy skin. Overdoses of more than 120 milligrams or a half cup of oil can cause severe damage to the liver and kidney, acute abdominal pain, vomiting, and sometimes, even death.
While fresh rue is more toxic, dry rue can also pose certain less extreme side effects. Hence, it should only be used under a physician’s prescription and thorough supervision.
‘Jackman’s Blue’ Rue
Jackman’s blue rue is also known as Ruta graveolens or herb of grace. It is popular for its aromatic greenish-blue foliage and small yellow blooms. It is regarded as the national plant of Lithuania, where it’s associated with virginity and the maidenhood of young girls. Traditionally, it has been used to make crowns for brides that signified maidenhood. Upon marriage, the crown is burned to mark the end of maidenhood for the bride. In addition, the variety was used to convey the sorrow after the loss of virginity in traditional English folk songs.
Due to its tolerance of dry conditions, Ruta graveolens is sometimes planted as an ornamental plant in gardens. A little smaller than its counterpart Ruta chalenpensis (fringed rue), Ruta graveolens comprises of 2 to 3 pinnately divided blue-green leaves. Its yellow flowers are characterized by loose inflorescence, while its pedicels are as long as the capsule. The flower holds 4 to 5 undulate petals that are finely toothed. However, unlike those in Ruta chalenpensis, the flowers of Ruta graveolens have no long cilia.
This variety originates from the Balkan Peninsula and the Krym. It has been introduced to parts of Northern Europe, too. While it has been introduced in the Greek mainland, it is yet to come to Crete.
In its first year of growth, Ruta graveolens requires well-drained and properly moisturized the soil. The plant then becomes highly tolerant to dry conditions in subsequent years. This variety appears attractive in rock gardens and borders.
Young plants of Jackman’s blue demand additional phosphorus to ensure good root development. Ideally, a specified amount of fertilizer with phosphorus should be applied according to the instructions on the bag, especially during the first growing season. To make sure that it thrives well, full sun should be provided – that means at least 6 hours of sunlight per day.
The perfect planting time is spring or fall when the soil is not vulnerable to frost. Planting in the fall season offers an added advantage. This is that the development of roots doesn’t have to compete with the development of top growth as it would have to in spring. Spring plantation is more suited to perennials that do not adapt well to wet or cold conditions, ensuring full establishment before winter. For most plants, summer or winter plantations are certainly not recommended.
A major concern for this variety is that fungal spores, which may develop in soil with excessive moisture, may come into contact with the plant, which leads to root rot or Phytophthora. This is a disease that first infects the leaves near the base and causes the roots to turn black or break. Afterward, it shrinks the base of the stem and causes discoloration. Finally, the upper leaves wilt and die. The disease often occurs due to the use of unsterilized soil mix or contaminated water.
Root rot cannot be controlled using chemicals. The best approach to protect the plant is to cut off the affected parts of the plant, including the roots, as well as discard the surrounding soil. Using sterilized and a fresh soil mix, replace the old plant with new, unaffected ones, and do away with fertilizing for some time. However, make sure that the area is properly drained before plantation and do not water excessively.
Although other diseases like stem rot and Rhizoctonia root look similar to root rot, the latter occurs in well-drained soils.
Source: Backyard gardener
Fringed rue, more commonly known as Ruta chalepensis, is mainly found in the Mediterranean region, such as in Portugal. Since it is a hardy variety, it has spread to most parts of Europe and in California, US. Within the Mediterranean region, you’ll find fringed rue extensively in rocky places such as the gorges of Crete, in the montane and sub-montane zones, dry banks and thickets and on limestone.
It’s a strange-looking flower with four to five yellow petals with a scoop-like shape that flowers from April until June. The yellow flowers are surrounded by a fringe of fine, long hairs. When the leaves are crushed, they release a bitter, unpleasant odor. When the shrub is flowerless, it appears blue-gray in color. This perennial herb typically grows to 20-80 cm in height and contains 10-20 cm leaves dotted with oil glands.
Leaves are strong-smelling and pinnately divided either twice or thrice, with oblong-elliptic to linear segments. While the overall plant is glabrous, the lower bracts are much wider than the branches, and the lower leaves have long stalks.
When you talk about the inflorescence of fringed rue, the pedicels are typically longer than the capsule. The strong scented flowers measure 2 cm across, appearing only on the central part of each inflorescence.
The superior ovary of fringed rue comprises of a floral receptacle that has been developed into a gynophore. Like all other members of the Rutaceae family, fringed rue contains a hypogynous disk that appears as a ring beneath the ovary along with the large glands.
Each of the 4 or 5-lobes of a rue flower emerges with a style of its own, but all styles eventually combine into one. Fruits of fringed rue feature long pointed erect lobes and countless angled seeds.
Rue flowers are a kind of jack-of-all-trades of the flower world. Not only does it have a long history that spans many, many years, but it also has multiple uses. Just remember to wear gloves when handling this particular type of plant or any of its variants.