A curious feature of New Zealand plants is the large number of shrubs with small leaves and flexible interlacing branches. This form is termed divarication or filiramulation. Divarication occurs across many plant families and curiously is found in some genera or species, but may not be prevalent in all the members of the genera. There are a number of theories put forward to explain this phenomena. One idea is that it is a defensive mechanism against browsing Moa. Moa did not browse in the same way as other mammal browsers (of which New Zealand had none). Small leaved woody tangled shrubs were unpalatable to Moa, so plants that created this divaricating form were naturally selected as being advantageous. Another theory is that this shape is advantageous in a dry, cold, windy, environment as may have been present in New Zealand in a previous ice age. The theory that I most adhere to, as I have observed this occurring, is that this twisted small leaved form creates an ideal habitat for lizards which are the primary agent of fruit and seed dispersal. The lizards are readily able to climb throughout the plant to digest the fruit and are hidden or protected by the interwoven branches. Whatever the answer, divarication is another special feature of New Zealand native plants.
