The Element Encyclopedia of Witchcraft: The Complete A-Z for the Entire Magical World - Judika Illes 2005
(Circaea lutetiana or Circaea alpine)
This is Circe’s plant; the enchanter in question is the Greek witch-goddess Circe. Other names for it include Walpurgis Herb, Great Witch Herb, Sorcerer of Paris (the Trojan prince, not the city), Paris Nightshade, Magic Herb, and Great and Common Witch’s Herb. In German, it’s called Hexenkraut (Witches’ Herb); its Anglo-Saxon name was Aelfthone, as it was believed to counter elf-derived illnesses.
Despite its common folk name, it is not as toxic as other plants nicknamed Nightshade, such as Black Nightshade, Deadly Nightshade or Russian Nightshade. There are two species of Enchanter’s Nightshade. The most common—Circaea lutetiana—is from Eurasia. It grows best near streams and damp, marshy places, often associated with witchcraft and magic.
A variation of the species prefers higher altitudes. Alpine Enchanter’s Nightshade (Circaea alpine) is also called Circe of the Alps. Both plants are associated with hexes, binding charms, and love spells. Enchanter’s Nightshade was one of the plants whose possession was sufficient evidence to warrant accusation of witchcraft.