Tranquility Vines

Tranquility vines are a form of flowering vine native to the Shengalvan Archipelago. They have beautiful, sweet-smelling flowers and their aroma is also calming to humanoids. People near tranquility vines can feel stress bleeding off slowly. They aren't soporific, just calming.
Incense can be made from the petals of the blossoms that has the same effect.