Heyo !
You need to collect 6 mushrooms, then drink a Kawa when fighting Eris, and use the skill "relax a bit" 3 times under the dead tree in the crossroad.
Viewing post in Ballad of Outstanding Bimbo Sorcery comments
Nope. If it can help, they're in the first few maps : the glade where you started, the forest part where you met Illonia, and the east part, where the gnome is selling. No need to search others maps ^^Although if you already opened the way using the stone tablet, they will have dissapeared, since they're not needed.