Best plants for natural water filtration/clarity

[bagsmom]

I'm thinking about my naturally maintained pond (that I hope to build sometime soon!) I'm going to build it as a frog/wildlife pond, with no electrical system or mechanical filtration - no pump.
What are some of the best plants for keeping water clean and clear?
I've heard iris are good.
What others?
Thanks, all!

 

[addy1]

Aracharnis is a great plant I have some in a fish-less pond and the tads love it. Also parrots feather. I bought some that should not survive our winter, I sank it into the deep pond and it is growing. Will be moving it into the more shallow ponds in a bit.