In my pond (6-7 acres), I have only been successful at getting lilies established at one spot which also happens to adjacent to where the most human activity takes place. In this spot, I planted two plants about 4 years ago, now there are 3-4 plants there and the span is about 8-10' at full. With this type of progression, I'm not worried about them overtaking the pond.
Unfortunately, I do not know the name of the specific lily.
As far as my other attempts to get lilies established in other areas, the turtles would get to them as soon as they sprouted a few pads, and that would be it.
This year, I'll be trying again but will be using a wire mesh staked around each new plant to guard against turtle attack.
EDIT: DanB, I do also have muskrats, and they may be working against me too.
