Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order: Asterales
Family: Asteraceae
Tribe: Astereae
Genus: Olearia
Species: O. lacunosa
Scientific name: Olearia lacunosa
Common name: Lancewood Tree Daisy,  Rough Leaved Tree Daisy.

Olearia lacunosa is an evergreen shrub or small tree, growing up to 5 m high and is found in subalpine to alpine forests (900m=2300m} from the Tararua Range southwards in North Island and mainly to the west of South Island, till above Franz Joseph Glacier.
The dark green narrow leaves are up to 17mm long and up to 5mm wide. The leaves have a prominent midrib and veins which impart an alveolate appearance to their lower surfaces.  The leaves underside are covered with a brown tomentum.  In spring/summer, it has flower heads of white daisy flowers

A mature tree photographed near Mt Arthur hut (Tasman region) at approximately 1100 masl.
[1]

A young plant photographed at Otari Native Botanic Garden and Wilton's Bush Reserve. Wellington.   
[2]

[3]

A photo showing the brown tomentum on the underside of a leaf.
[4]

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