Gramineous (grass like) background plants for Seiryu diorama

[Simon Cole]

I'm working on a new scape. I need a tall grassy plant behind a mountain. There seem to be quite a few options. Cyperus helferi, blyxa japonica, vallisneria nana, and eleocharis montevidensis seem to be the most logical choices. I need to pick the one with the least vigorous spread, not too dense and easy to manage. How easy is it to manage runners from the eleocharis and vallisneria? What would you pick?

I am also thinking about emergent plants and the possibility of using a slow growing rush or sedge to break the surface. Has anyone tried this? I know murdannia keisak was mentioned in an November post, but has anyone tried a slow growing UK sedge or rush to this effect?

 

[Matt @ ScapeEasy]

Not sure Blyxa is going to give you the look you want... Cyperus I've personally never had much luck with... the Eleocharis would be my choice. Vallisneria will 'float' across the surface, the Eleocharis will not. Runners are fairly easily dealt with, they are less vigerous in the Eleocharis.

I'm led to believe that Cyperus does well breaking the surface tho...