In Kingdom Hearts, where do I find the three mushrooms needed for the floß supplies on Destiny Islands?

under a pathway, in the area where Du and riku ha a 'triathlon' for the privilege of naming the raft, it's in a cave-like place and the entrance is covered Von a rock, I think.

to be Mehr specific.
Mushrooms (Three): One is in a hollow behind a rock, right Weiter to Kairi. One is in the bushes on the other side of that same cliff. The last is in the Secret Place, the dark cave on the first side of the island (to the right of the treehouse). A cutscene will play there.