The leaves on its head are very bitter. Eating one of these leaves is known to refresh a tired body.
Since they prefer moist, nutrient-rich soil, the areas where Petilil live are known to be good for growing plants.
The leaves on its head grow right back even if they fall out. These bitter leaves refresh those who eat them.
Although the leaves on its head are bitter enough to cause dizziness, they provide relief from weariness—even more so when boiled.
By pruning the leaves on its head with regularity, this Pokémon can be grown into a fine plump shape.
— Pokédex entries (via PokeAPI)