My grandmother and I were just talking about this last night. She converted all of her flowerbeds to native wildflowers last year and was really thrilled with all the butterflies, particularly monarchs, that it drew. I have never seen a butterfly emerge from it's chrysalis before, but she got to see dozens of them go through their stages this summer.
I had found about 10 monarch catepillars eating on my black anise this year (which is funny, because I've had that anise for about 5 years now and have never seen them on it before). I watched them for a couple days but never saw where they went after that. I wonder where they decided to hang their pupa...
I've also seen them all over my parsley last summer. Now I really don't know where they could have gone from there. I would think something would have eaten them before they made it far enough to reach a tree or anything tall enough to hang from.
It's amazing that they can turn into a butterfly in only 10 days!