Carex Geminata

These are excellent wetland grasses and absolutely perfect for planting alongside streams and duck ponds in wetlands.  

Their habit supports a lot of insects and when planted on waterways can help with fish spawning and feeding too as well as creating cover for nesting waterfowl. 

They are low growing so can keep areas open where you want to enjoy the amenity value.

If you're after a mass planting around cattle yards/milking sheds or around a duck pond then getting a few hundred of these in will look great.