Gilghamut is half right. Well, more than half. But it's just a saying.

You must have completed the little annoying cactuar hunt thing. Then you take the flower to the guy's wife, who then sends you on a massive great journey, eventually ending in a Barheim Key. Also, if you keep something to do with a serpent, you can get a Golden Amulet fairly early in the game.

Wow, that was well phrased. Renmiri will come along soon and show us all how it's done.