The ingredient Primrose Leaves comes from the plant "Primrose". There are actually two varieties of this plant (one with pink flowers and one with purple flowers), both of which yield the same ingredient. Primrose flowers are found sporadically in the West Weald, Heartland, and Nibenay Valley regions.
Primrose Leaves are one of only three ingredients which can be used to create a Fortify Luck potion at journeyman level or higher, and Primrose Leaves are the only ingredient which can be used to create Fortify Luck potions that do not have a Damage Fatigue negative side-effect. Primrose Leaves can be combined with either Bonemeal or Green Stain Shelf Cap.
Two guaranteed samples can be found, in the following locations:
It can also be found randomly in the inventories of alchemy vendors.
The places with the highest concentrations of Primrose Leaves are: