Harry potter and the half blood prince on ds?

I am playing harrry potter and the half blood prince on ds and need to find ingredients to a potion, peppermint sprigs, shrivelfig and porcupine quills.i know the quills r located in charms clroom but can't figure it out, i cant find a student for peppermint quills and I have no clue where to find the shrivelfig. Can anyone help me?????