Shinon is looking to make some medicine and needs you to find the special leaves. Unfortunately, she is unaware that you are actually looking for a Pokémon. It is time to go search the Crimson Mirelands for a three-leaved Pokémon. Here is how you complete the Search for Bitter Leaves request in Pokémon Legends: Arceus.
This request appears after you unlock the Crimson Mirelands. You can find Shinon along the central road in Jubilife Village. Once you speak to her, turn around and head into the house indicated by the marker. Inside, you will talk to Anise. She will inform you that the leaves Shinon is looking for are on a Pokémon. Now you need to hunt down the Pokémon down.
Head to the Crimson Mirelands and head east to the area indicated by the stamp on the map above. There are a few ways you can reach this location if you can’t go through the water or fly yet. Summon your Wyrdeer and use it to climb a cliff along the riverbed. From a high enough area, you can jump and make it far enough that you can swim to shore. The area you are looking for is Cottensedge Prairie. You will know when you are there because you will see a field of white flowers. This is where you can find Petilil.
Catch a Petilil and return to Anise. Once you hand over Petilil, Shinon will enter the house. You will receive your reward after the cutscene.
