That is emersed growth DHG. It will change into it's immersed growth form over time which is what I was looking at not even thinking about how it looks when it's grown emersed. It appears to have a fuzz algae on it. Did it come that way or did it get this after being in your tank? How long do you run your lighting daily? What type of light fixture and bulbs are you using? Do you know your nitrate and phosphate levels? When dealing with algae only run lighting 6 hours daily until it's gone. Plus remember that the higher the light used in a tank the shorter the photoperiod has to be in order to keep algae under control.
You can spot treat the algae by using 3ml of hydrogen peroxide 3% for every 1 gallon of tank water. Pull that amount up in a syringe, turn off filters, squirt the algae, and leave filters off for 20 minutes. Reduce lighting and you should see the algae die off.