Kingdom:   Plantae
(Unranked):        Angiosperms
(Unranked):        Monocots
(Unranked):        Commelinids
Order:       Poales
Family:      Cyperaceae
Genus:      Carex
Species: C. morrowii
Binominal name: Carex morrowii
Common name: Morrows Sedge, Japanese sedge
Cultivars: Variegata, Gold Band,  Evergold, Silver Tassel, Ice Dance, Fisher’s Form.

Carex morrowii a Japanese exotic clump-forming evergreen ornamental grass with stiff, dark green leaves with narrow white edges; 30cm long. It will form a clump with a height of 30-40 cm and will stand temperatures down to minus 15 c. and is drought tolerant.  In spring short-lived groups of four to six flowers on spikes appear;

Photographed at Pukekura Park, New Plymouth
[1] 

[2]

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