Berra wants you to complete the Pokédex entry for Roselia and show it to her.

The Request

Talk to Berra at Mirelands Camp to accept her request.

Complete Roselia's Pokédex Entry

Complete research tasks in Roselia's Pokédex entry until the entry reaches research level 10. Roselia can be found in Crimson Mirelands, in the Gapejaw Bog area and the Cloudpool Ridge area.

Reward

After you complete Roselia's entry, talk to Berra at Mirelands Camp to get 5 Grain Cake and 2 Exp. Candy S.