Water Gardening: Plant With No Name, 1 by CindyInAZ

CindyInAZ wrote:
My husband recently built a small koi pond in our front courtyard so I'm a newbie here. I was going to list this on the Plant Identification Forum but this one is more specific. We added this plant which we found at a Plant Sale but it has no name. I'd like to read up on it so if anyone knows what it is, I'd appreciate any information you can offer.

It is sending runners all over the place and I am just hoping it may not be too invasive for my small pond. Thanks in advance.