Vinh - Prolifera is large bladeed with runners that attach along bottom - there is a good pic here:

www.floridapets.com
I have 'manatee grass' I believe in my refugium - Syringiodium ? Does little for export as far as I can tell but ihave it established and have gotten a few new shoots which I'm happy about - When tank gets moved over to my 215 it will have a lot of the rock taken out so more sandbed for the grass to hopefully spread - am also going to beef up the lighting.