Vervain / Verbena

Vervain or Verbena is a genus in the family Verbenaceae. It contains about 250 species of annual and perennial herbaceous or semi-woody flowering plants.

According to the ancient Egyptians this divine herb came from Isis's tears when she wept at the death of Osiris her lover/partner/brother, the ancient Greeks called it Hera' tears, the Romans Juno's. It was dedicated to Eos Erigineia, a Titaness and the goddess of the dawn, who rose each morning from her home at the edge of the Oceanus.
Many societies believed vervain held hidden powers. In Persia it was the herb of prophecy for the magi: mystic sages. Revered by many cultures and peoples for millennia it was one of the most sacred herbs to the Druids, who are said to have gathered it from shady places, preferably when Sirius, the dog star was  rising, before sunrise, to utilise for divination, consecration and cleansing sacred spaces. It is described as having been presented on Jupiter altars.
in many Central and Eastern European languages the name is often associated with iron. e.g.  Dutch; Ijzerhard -iron-hard, Danish; Læge-Jernurt - medical iron root, German; Echtes Eisenkraut true iron herb, Slovak; Železník lekársky medical iron herb, Hungarian; vasfű - iron grass. 1
In Greek texts it was suggested for treating fever and plague. Aztecs used the root as a diuretic they named it “medicine for urinating”. In other areas of the Northern  Americas, other Nations used it to boost circulation, for headaches and insomnia. Chaticks si Chaticks (or "Men of Men, usually referred to as) the Pawnee have adopted common vervain as an entheogen enhancer and in oneiromancy (dream divination). Christians call V. officinalis "Herb of the Cross, Holy Herb or Devil's Bane because  'it was used to staunch Jesus' blood when he was taken from the cross'.
In The History and Practice of Magic a book written in 1870 by "Paul Christian" (Jean-Baptiste Pitois) it is used to prepare a mandragora charm.The book tells of it's antiseptic capabilities (p.336), and use as a protection against spells (pp.339, 414).

Despite it's long and varied use there are few human trials and inconsistent direction in those with animals2

When used to combat depression and mood swings, it is said that, this deeply penetrating nervine soothes and sedates the nervous system, is relaxing and uplifting, yet can stimulate the release of (the neurotransmitters) dopamine and serotonin, enhancing mood and well being.
Vervain is said to be effective in promoting a good night's sleep without a groggy feeling in the morning. Studies have found that the compound in Vervain responsible for inducing sleep is verbenalin - an iridoid glucoside.
A “bitter herb”, Vervain is called a digestive stimulant, which means it improves digestive function by increasing saliva production, and promoting stomach acid and digestive enzyme production.
It is said to be especially good when digestive issues are stress related – if we are stressed our digestion can shut down;  it is seen as non essential when dealing with a serious threat. The fight or flight stress response is prioritised over freeze. Vervain suposedly helps to stimulate the appetite by relaxing the stomach when tension is held there. As a tea many have found alleviation of cramps, bloating and flatulence.
Vervain active ingredients include aucubin and oleanolic acid, these powerful plant compounds suggest hepatoprotective benefits.
Vervain tea can purportedly help to stimulate the liver and encourage healing of any damage. If consumed on a regular basis it should help to strengthen the liver, supporting the elimination of toxins from the body.
It is a diuretic, assisting in flushing out unwanted toxins, especially from the urinary tract, this helps combat water retention, which improves kidney function. Apigenin is a compound of the plant that has also been found to prevent kidney damage.3