Rue Perrée

''Ruta graveolens'', commonly known as rue, common rue or herb-of-grace, is a species of ''Ruta'' grown as an ornamental plant and herb. It is native to the Balkan Peninsula. It is grown throughout the world in gardens, especially for its bluish leaves, and sometimes for its tolerance of hot and dry soil conditions. It is also cultivated as a culinary herb, and to a lesser extent as an insect repellent and incense.

Etymology

The specific epithet ''graveolens'' refers to the strong-smelling leaves.J. D. Douglas and Merrill C. Tenney

Description

Rue is a woody, perennial shrub. Its leaves are oblong, blue green and arranged pinnate; they release a strong aroma when they are bruised.

The flowers are small with 4 to 5 dull yellow petals in clusters. They bear brown seed capsules when pollinated.

Uses

Traditional use

In the ancient Roman world, the naturalists Pedanius Dioscorides and Pliny the Elder recommended that rue be combined with the poisonous shrub oleander to be drunk as an antidote to venomous snake bites.

The refined oil of rue is an emmenagogue and was cited by the Roman historian Pliny the Elder and Soranus as an abortifacient (inducing abortion).

Culinary use

Rue has a culinary use, but since it is bitter and gastric discomfort may be experienced by some individuals, it is used sparingly. Although used more extensively in former times, it is not a herb that is typically found in modern cuisine. It is a component of berbere, the characteristic Ethiopian-Eritrean spice mixture, and as such is encountered in their cuisine. Also in Ethiopia, fresh rue is dipped in coffee before drinking it. Due to small amounts of toxins it contains, it must be used in small amounts, and should be avoided by pregnant women or women who have liver issues.

It has a variety of other culinary uses:
* It was used extensively in ancient Near Eastern and Roman cuisine (according to Ibn Sayyar al-Warraq and Apicius).
* Rue is used as a traditional flavouring in Greece and other Mediterranean countries.
* In Istria (a region spanning Croatia and Slovenia), and in Northern Italy, it is used to give a special flavour to grappa/ raki and most of the time a little branch of the plant can be found in the bottle. This is called ''grappa alla ruta''.
* Seeds can be used for porridge.
* The bitter leaf can be added to eggs, cheese, fish, or mixed with damson plums and wine to produce a meat sauce.
* In Italy in Friuli Venezia-Giulia, the young branches of the plant are dipped in a batter, deep-fried in oil, and consumed with salt or sugar. They are also used on their own to aromatise a specific type of omelette.
* Used in Old World beers as flavouring ingredient.

Other

Rue is also grown as an ornamental plant, both as a low hedge and so the leaves can be used in nosegays.

Most cats dislike the smell of it, and it can, therefore, be used as a deterrent to them (see also '' Plectranthus caninus'').

Caterpillars of some subspecies of the butterfly '' Papilio machaon'' feed on rue, as well as other plants. The caterpillars of '' Papilio xuthus'' also feed readily on it.

Hasidic Jews also were taught that rue should be placed into amulets to protect them from epidemics and plagues. Other Hasidim rely on the works of a famous Baghdadi Kabbalist Yaakov Chaim Sofer who makes mention of the plant "ruda" () as an effective device against both black magic and the evil eye.

It finds many household uses around the world as well. It is traditionally used in Central Asia as an insect repellent and room deodorizer.

Toxicity

Rue is generally safe if consumed in small amounts as an herb to flavor food. Rue extracts are mutagenic and hepatotoxic. Large doses can cause violent gastric pain, vomiting, liver damage, and death. This is due to a variety of toxic compounds in the plant's sap. It is recommended to only use small amounts in food, and to not consume it excessively. It should be strictly avoided by pregnant women, as it can be an abortifacient and teratogen.

Exposure to common rue, or herbal preparations derived from it, can cause severe phytophotodermatitis, which results in burn-like blisters on the skin.

Chemistry

A series of furanoacridones and two acridone alkaloids ( arborinine and evoxanthine) have been isolated from ''R. graveolens''. It also contains coumarins and limonoids.

Cell cultures produce the coumarins umbelliferone, scopoletin, psoralen, xanthotoxin,