[--Chris--]

In case you're still confused, it's by that town with the red trees to the top left of the map =O

You hit these little bushes a few times, when they are cut down there's a chance of you finding a mushroom underneath. You have to wait for them to fully grow back before you could start chopping 'em down again. 5 mushrooms = 1 gralat. You sell them to this npc north of where you picked the mushrooms. It's almost as efficient as pearl diving =O