Wubbzy

I'm at the part of the game on the SS Anne where i need to find the pharmacist to give the captain a potion. Guides have told me there is a blissey on the third floor that will give me something to give to the pharmacist to make the potion, this blissey is not there. A friend told me i needed a pecha berry but ive picked all of the berry trees in the game so far and have double checked. Please help.