Stereum ostrea is a native, but non-endemic bracket fungus that is a plant pathogen that grows on tree bark and decaying wood. This fungus is relatively common in native forest on dead and dying trees. The fungus is inedible.
This example is from Pine Valley in Mount Richmond Forest Park on the waterfall track.
Location: Latitude: -41.502518 Longitude: 173.504883"
Image Date: 3/11/2014
Photographer: Christopher Cookson