Common rue is an herb of many connotations. It also known as herb of grace, or herbygrass, from its use in the early Roman Catholic Church to sprinkle holy water and wash away sins. (Hyssop was the herb of choice in the Middle Ages, but rue was also used, perhaps because of its long-standing reputation as a disinfectant.) The custom derived from a Roman ceremony (using a laurel branch) to purify weapons and standards following a battle.

Rue is associated with sorrow, regret and compassion only in the English language. When the Romans introduced the rue herb plant to England, they called it by its Latin name (now the generic name), Ruta. When Anglicized and shortened to rue, the name sounded just like the word meaning sorrow, but that word comes from an Old English word, hreow. (Some believe that the word Ruta comes from a Greek word meaning to set free. The specific name, graveolens, is Latin for having a strong or offensive smell (dill is Anethum graveolens). Whether rue odor is either strong or offensive is open to debate; usually, it described as musty.
Ruta is the genus belonging to the family Rutaceae, members of which include aromatic citrus trees as well as gas plant (Dictamnus albus), a lovely white- or pink-flowered perennial.

It is also is one of the host plants to the Black Swallow Tail butterfly, It attracts other butterflies bee's, wasp and other insets, That my friend is why I have Rue in my garden