In order to repair one of the bridges on Misty Mountains, you need to do the quest with Bindweed plant. But sometimes the task can't be found in the list of quests. How to get it?

If you don't have this task, it means that there are still some flower seeds that you can study. In Gloria's Laboratory, there is a Flower collection tab where you can check which flowers you still need.

Here's a little guide on where to look for the flower seeds: https://quartsoft.helpshift.com/hc/faq/331-flower-seeds-on-misty-mountains/

Make sure that you open new parts of the island in both directions.