A number of Chatham Island plants show morphological differences from related plants on mainland New Zealand. These differences could have arisen as a result of freedom from moa browsing on the Chatham Islands. A possible test for this hypothesis is suggested.
To test the hypothesis that the divaricate habit protects internal leaves from cold and dry conditions, and raises leaf temperatures on cold sunny days, thermocouples were attached to internal and external leaves on divaricate plants. For Coprosma propinqua plants at Cass, inland Canterbury, there were consistent differences in temperature between leaves, but these were not simply related to their canopy position (interval vs. external).