I have tried before to identify New Zealand lichens, but there is no handy identification guide. David Galloway's Lichen Flora of New Zealand, is way too technical for limited understanding, so I guess we'll just have to admire these as lichen-landscapes!
However, I am reasonably confident that this is Teloschistea chrysophthalmus. Comparing another photograph on the Forest lichens website. Of course, matching photos is probably a silly way to identify things, but never mind. And of course, Chryso- means golden coloured.
The grey 'spread-out' foliose form is what I habitually call Parmelia, which in a NZ context probably means its in the Parmeliaceae family, rather than the genus per se.
The brown bumps - are tree trunk scars - typical of most Prunus species, but particularly noticeable on this ornamental flowering cherry-tree. It was here when we moved into the house, so we have no idea what variety it is. Dunedin has plenty of these pink cherry trees, in public spaces as well as private gardens. Spring is early this year, and already there are three or four blooms. Elsewhere in town some of the early flowering pink rhododendrons are in flower, leastways those that are sited in choice sunny positions.
