Crocus

Crocus were a family of small sun-loving and delicate flowering plants of lavender or purple color. Growing almost exclusively around the city of Carcassonne
These flowers were valued for the Saffron harvesting, and for its memorable sweet scent
When processed through alchemy, a sublimate of Autumn Crocus  could be created. It was then mixed with a certain type of essence to make potions of feather fall.