All ingredients available to Hogwarts students are listed here. Includes any magical properties for use in potions, and extra tips on how to locate them. Some ingredients may be used to obtain others.
Found ~ Where to search, though some are difficult. May need special circumstances or to overcome a challenge to collect them.
Obtained ~ NPC character that gives you the ingredient in exchange for completing a task. RP-wise, ask if they know where to find the specified ingredient. If non-human NPC, just complete the mentioned task or interaction. No exp rewards are given.
Bought ~ Self-explanatory; Wizshop. Doesn't count towards getting a Potions Kit. No exp rewards are given.
Rewarded for ~ Unless otherwise specified, it's an inventory reward only and not something you RP getting.
Grown ~ Must be grown from its specified seed using the Herbology Kit.
~ A kit isn't required to receive this ingredient, only to use it. Doesn't count towards getting a Potions Kit.