A mundane plant used as a potions ingredient.
Lavender is an ingredient in a Sleeping Draught (Pm).
From Latin "Lavendus" meaning "wash" referring to the practice of drying clothes on lavender bushes to add a pleasant scent
The essential oil from lavender has been used for centuries to sooth various maladies including headaches and insomnia. To aid sleep, pillows were sometimes stuffed with dried lavender flowers. Source: Complete Herbal