Ruta graveolens

Ruta graveolens Common rue
Common rue in flower
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Sapindales
Family:	Rutaceae
Genus:	Ruta
Species:	R. graveolens
Binomial name
Ruta graveolens L.

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 now 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 medicinal herb, as a condiment, and to a lesser extent as an insect repellent.

Uses

Traditional use

Illustration in the Tacuinum Sanitatis

The Tacuinum Sanitatis, a medieval handbook on wellness, lists these properties of rue:

• Nature: Warm and dry in the third degree.
• Optimum: That which is grown near a fig tree.
• Usefulness: It sharpens the eyesight and dissipates flatulence.
• Dangers: It augments the sperm and dampens the desire for coitus.
• Neutralization of the Dangers: With foods that multiply the sperm.

The refined oil of rue is an emmenagogue^[1] and was cited by the Roman historian Pliny the Elder and the gynecologist Soranus as a potent abortifacient (inducing abortion).

A "crown of rue" or crancelin on the heraldic banner of Saxony

Culinary use

foliage

Capsule and seed - MHNT

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 an herb that is typically found in modern cuisine. Today it is largely unknown to the general public and most chefs, and unavailable in grocery stores.^[2] It is a component of berbere, the characteristic Ethiopian spice mixture, and as such is encountered in Ethiopian cuisine.

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 in Croatia), 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.^[3]
• Used in Old World beers as flavouring ingredient.^[4]

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.^[5]

In South India, rue is recommended for home gardens to repel snakes (however the effectiveness is unknown).

Rue is also a common ingredient in witchcraft and spell making. During the Middle Ages it was a symbol of recognition between witches. The Catholic Church also used a branch of rue to sprinkle holy water on its followers during this time known as the "herb of grace."

Toxicity

Rue extracts are mutagenic and hepatotoxic.^[1] Large doses can cause violent gastric pain, vomiting, systemic complications, and death.^[1]

Exposure to common rue, or herbal preparations derived from it, can cause severe phytophotodermatitis which results in burn-like blisters on the skin.^[6][7][8][9]

Effect of the common rue on skin in sunny weather

Chemistry

R. graveolens essential oil in a clear glass vial

A series of furanoacridones and two acridone alkaloids (arborinine and evoxanthine) have been isolated from R. graveolens.^[10] It also contains coumarins and limonoids.^[11]

Cell cultures produce the coumarins umbelliferone, scopoletin, psoralen, xanthotoxin, isopimpinellin, rutamarin and rutacultin, and the alkaloids skimmianine, kokusaginine, 6-methoxydictamnine and edulinine.^[12]

The ethyl acetate extract of R. graveolens leaves yields two furanocoumarins, one quinoline alkaloid and four quinolone alkaloids.^[13][14]

The chloroform extracts of the root, stem and leaf shows the isolation of the furanocoumarin chalepensin.^[15]

The essential oil of R. graveolens contains two main constituents undecan-2-one (46.8%) and nonan-2-one (18.8%).^[16]

Symbolism

The bitter taste of its leaves led to rue being associated with the (etymologically unrelated) verb rue "to regret". Rue is well known for its symbolic meaning of regret and it has sometimes been called "herb-of-grace" in literary works. It is one of the flowers distributed by the mad Ophelia in William Shakespeare's Hamlet (IV.5):

"There's fennel for you, and columbines:

there's rue for you; and here's some for me:

we may call it herb-grace o' Sundays:

O you must wear your rue with a difference..."

It was planted by the gardener in Richard II to mark the spot where the Queen wept upon hearing news of Richard's capture (III.4.104–105):

"Here did she fall a tear, here in this place

I'll set a bank of rue, sour herb of grace."

It is also given by the rusticated Perdita to her disguised royal father-in-law on the occasion of a sheep-shearing (Winter's Tale, IV.4):

"For you there's rosemary and rue; these keep

Seeming and savour all the winter long."

It is used by Michael in Milton's Paradise Lost to give Adam clear sight (11.414):

"Then purg'd with euphrasy and rue

The visual nerve, for he had much to see."

Rue is used by Gulliver in "Gulliver's Travels" (by Jonathan Swift) when he returns to England after living among the "Houyhnhnms". Gulliver can no longer stand the smell of the English Yahoos (people), so he stuffs rue or tobacco in his nose to block out the smell. "I was at last bold enough to walk the street in his (Don Pedro's) company, but kept my nose well with rue, or sometimes with tobacco".

Rue is mentioned in the Bible, Luke 11.42: "But woe unto you, Pharisees! For ye tithe mint and rue and all manner of herbs".

In mythology, the basilisk, whose breath could cause plants to wilt and stones to crack, had no effect on rue. Weasels who were bitten by the basilisk would retreat and eat rue in order to recover and return to fight.

Rue is considered a national herb of Lithuania and it is the most frequently referred herb in Lithuanian folk songs, as an attribute of young girls, associated with virginity and maidenhood. It was common in traditional Lithuanian weddings for only virgins to wear a rue (ruta) at their wedding, a symbol to show their purity. Likewise, rue is prominent in the Ukrainian folklore, songs and culture.

In the Ukrainian folk song "Oi poli ruta, ruta" (O, rue, rue in the field), the girl regrets losing her virginity, reproaching the lover for "breaking the green hazel tree".^[17] "Una Matica de Ruda" is a traditional Sephardic wedding song.

"Chervona Ruta" (Червона Рута—"Red Rue")—a song, written by Volodymyr Ivasyuk, a popular Ukrainian poet and composer. Pop singer Sofia Rotaru performed the song in 1971. More recently Rotaru performed in a rap arrangement.

See also

• Peganum harmala, an unrelated plant also known as "Syrian rue"

References

External links

Wikimedia Commons has media related to Ruta graveolens.

• Rue (Ruta graveolens L.) page from Gernot Katzer's Spice Pages