Wormwood (Artemisia absinthium) is a bitter herb historically used in European traditional medicine, particularly as an aperitif to stimulate appetite and aid digestion. It is known for its intensely bitter taste and is an ingredient in the alcoholic beverage vermouth.
In our times, probably the most bitter plant that people used in European terms was something called wormwood. Now you may not be familiar with that word but the French for wormwood is vermouth and you think of the use of a drink before a meal.
""Dr. Simon Mills identifies wormwood as a historically significant 'bitter plant' used in European medicine to stimulate appetite and digestion, explicitly linking it to its medicinal properties and its use as an aperitif."