The term bane (from Old English: bana, meaning "thing causing death, poison"), in botany, is an archaic element in the common names of plants known to be toxic or poisonous.
In the Middle Ages, several poisonous plants of the genus Aconitum were thought to have or prophylactic qualities, repelling and protecting against that which they were banes to (e.g. Henbane, Wolfsbane).
There is no single species, genus, or family of poisonous plant exclusively referred to as banes. Several unrelated plants bear the name.
In medieval Europe, the toxic entheogen Aconitine was believed to prevent werewolves from undergoing their dire transformations.
In the Southeastern United States, sheep and cattle straying into woodland and grazing Kalmia latifolia have been known to suffer from its toxic effects.