I had no idea what this was but it has been suggested that it could be Geranium rubescens. It was in a slightly boggy area on the foothills of Mt Hikurangi.
Hi Malcolm, G. potentilloides is known from that area. From what can be seen of the leaf I don't believe it is G. rufescens
Here is a better shot just of the leaf.
Hi Malcolm I would agree with Mike. The leaves are a little different to what I usually see though. See attached.
(JPG format, max 500kB)