The New Zealand Plant Conservation Network

Does anyone know what type of grass this would be? Seems to grow well in water; has a very pronounced white (or light green?) midrib

And here is a detail cropped out of the above photograph

Hi Danilo, to me it looks like Austroderia fulvida. What time of year was photo taken? and where?

Photo was taken 30 September 2015 at the mouth of Waiopaoa Stream, Lake Waikaremoana. I was meant to write the location in the comment above, sorry I forgot!
I had been wondering about Austroderia fulvida, which is widespread at Lake Waikaremoana, but can't quite match the description, especially the white midrib.

Probably Austroderia fulvida as common in that habitat at Lake Waikaremoana

Thank you Matt and Mike!