Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Monocots
(Unranked): Commelinids
Order: Poales
Family: Poaceae
Genus: Festuca
Species: F. coxii
Binomial name: Festuca coxii
Synonyms: Agropyrum coxii, Festuca glauca 
Common name: Cox’s fescue

Festuca coxii is a frost hardy native blue-green-greyish green tussock of flowing habit up to 35 cm tall and 40cm wide. The leaves which have pointed tips are about 40 cm long and 1mm wide. The leaves edges are slightly in rolled so they appear cylindrical. It produces 40 – 45 cm long flowering stems in November – January with 4cm long inflorescences.
Dr Alan Stewart describes in an article in the New Zealand Garden Journal, 2003, Vol. 6 (2) how to identify closely related European species.
http://www.rnzih.org.nz/RNZIH_Journal/Page11_from_2003_Vol6_No2.pdf

Festuca coxii is endemic to the Chatham Islands only where it has been grown in peaty turf amongst petrel burrows on exposed, coastal wind-blasted ridgelines.

Photographed at Otari Native Botanic Garden and Wilton's Bush Reserve. Wellington[1] 

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