I've poked around the interwebs quite a bit and I can't figure it out.

It grows in very shallow water. Only around the edge of the pond.

Looks like some variety of arrowhead. Not sure tho.

It could possibly be water hyacinth but we will let the experts chime in.
Dave

It could be arrowhead. When my arrowhead sprouts up, they have a more spear shaped leaves, but then start to develop into the flying "V" before they get leaves longer than a couple inches.

It could a be pickerel weed or, maybe, lizard's tail. Either way, keep an eye on it and post some more mature pics, especially if it flowers.

I don't think it's water hyacinth or at least not the floating kind.

If it's pickerel weed (my bet), you are blessed to have it. Especially if you like Arrowhead. They both live in the same locations of the pond and flower nicely.

Flowers would help a lot to verify the correct name. Watch it and get back to us when you see it gets larger and hopefully flowers.

The picture shows up as a small box with an x in it. I'm on a work computer so might now have correct software. Anybody know the problem?

I have some that is similar too so I will post a picture as well to verify if it is the same plant. I hope it will establish at my pond as well.

Many people here use 3rd party hosts rather than the PondBoss method for photos that are blocked by your big brother.

TinyPic has been semi-busted the last few days. I received notice this morning that they are going to be shutting down permanently sometime in 2019.

So I'm going to have to figure out a new place to put my pics.
And edit a lot of posts.
Ugh.

This pic has newly-sprouted arrowhead and the yet-to-be-identified mystery plant.

I think it's going to take letting it grow some to figure out what it is.

Here is a pic of the only bloom to date from some of the mystery plants that you gifted me. I thought it was going to be Water Arum, but the flower has set me back. I am currently at a loss...anybody?

I got it - 99% sure...Heteranthera Reniformis or Kidneyleaf Mud Plantain or Floating Leaf Mud Plantain. Seems to be native to North, Central, and South America, but listed as endangered in Illinois and Ohio and of special concern in Connecticut...

https://plants.usda.gov/core/profile?symbol=HERE

I haven't seen any bad reviews on it, so all must be good.

Looks like the same stuff to me. I like it in my pond so far.

One thing I did read about it said that it has a bad time competing with grasses, rushes, and such as they tend to block the sun from getting to these low lying plants which chokes them out.