Also looks like green algae to me. Grows quickly and covers all surfaces in the aquarium, often giving off an unpleasant swampy or fishy odor. I have found that it is most of the time its High levels of organic wastes. There are a few ways to get rid of it. Depends on what you have in the past few weeks that made thats start to see what needs to be done.
I got rid of some by syringing 3ml of 3% hydrogen peroxide on it.
Now I see the U. Ribba entangled in the moss, THATS whart I have to get rid of.
Spose I could get to work untangling the stuff from the moss. It sure does look like a PITA tho.