Euphorbia mellifera

Honey spurge. This one's names are due to its honey scented flowers, but the real apeal is hardy, drought tolerant bold form and texture. Up to 1.5 m round. Never a small tree here, despite many years. Also loves moisture and a modicom of shade where it grows more lax and has larger thicker leaves, looking like an island giant which it is, but perhaps it even looks succulent enough to be from our offshore islands too. There is a beautiful, luscious specimen sprawling about to about 1.2m at Fisherman's Bay Garden on Banks Peninsula. It looks great all year anywhere with its bright green leaves and bright midrib in any situation.  Drainage and sun or moisture and part shade, take your pick. 

Fully hardy.

Wikimedia commons, habitat photo