Mist Trees are collectables in Xenoblade Chronicles. They can be found in Satorl Marsh.
Satorl Marsh - the following location has the highest spawn rate (25%) for Mist Tree (night only):
※ After completing the Mechonis Core and Zel Argentis has not been invited to Colony 6. Or during Stopping the Elopement only, if she has been invited to Colony 6.
Giving this collectable as a present from one player character to another will raise or lower the affinity between them as indicated by the following table: