It is difficult to get a good picture with it being so small.

It doesn't have broad leaves like the pictures of the aquatic mosses I found on line. It is very small, somewhat spiny, fine/breaks apart easy and appears to have no firm root system. It is covering the bottom of my pond which is red clay and muck.

I sent a sample to a local pond chemical vendor and may also ask my local DNR. It is taking over my pond quickly as it did last summer.