We had some good lighting tonight so I was messing around with the camera.
Could be a type of cardinal flower?
Pecan your floating island looks like it is held up quite well, did you put anything on it to make it look natural or did it just age on its own.
http://davesgarden.com/community/forums/t/1360945/
Join this site, post a picture of the plant and they will tell you within a day what it is called. I have done that for a few aggressive weeds we have around here, and some trees.
I think I had the same plant in arizona, but sure can not recall the name of it
Great photos!