Butterfly Garden

Our home is a 1950's bungalow complete with an original swimming pool (nothing fancy, just a huge rectangle) that I am trying to landscape. Right now it's a mess with only a concrete border and various weeds and plants fighting to take it over.
One plant (or weed) has turned into a butterfly/hummingbird magnet. I don't know what this thing is, it's loaded with small flowers and draws hundreds of butterflies as well as the occasional humming bird.
When I re-landscape the area I'm going to have to move this colorful weed next to the pond. I was able to snap a few photo's of some butterflies yesterday.