Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Cyperaceae
Genus: Carex
Species: C. lessoniana
Binomial name: Carex lessoniana
Synonym: Carex polystachya
Common name: Spreading swamp sedge, Rautahi, Cutty Grass 

Carex lessoniana is a robust wetland sedge found throughout New Zealand but only sporadically in the far south. It grows usually on the margins of peat swamps, or in very wet alluvial forests from coastal to lowland (rarely montane).
Carex lessoniana which has wide-creeping rhizomes forms green tussocks >1m in height and a spread >2m. The bi-fold leaves have scabrid (rough) margins.
Flowering occurs during October to December and the fruits appear during December to April on long hanging green spikes that turn brown. The seeds when ripe are dispersed by seed predation and by water 

For more details visit: http://www.nzpcn.org.nz/flora_details.aspx?ID=1412

Carex lessoniana.JPG 

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0