I'll add 20% to your guess because that's exactly what it is. Amano uses it extensively in backgrounds.Eleocharis Vivipara. I'm 80% sure it is.
No, I have V. nana and it grows up to 24". The only thing 'nana' about it is the width of the leaves.I'm pretty sure that's Valissneria nana, E.v is a little short for that, the tank is like 12"+ tall.