If you look closely beside the track through the stunted beech forest you will see dark, extremely twiggy shrubs bearing small green leaves. This is Pittosporum lineare. It is a feature of the beech forest in small patches in the park. It has seeds that are embedded in thick pitch which helps dispersal by birds. Most species of Pittosporum are normal looking leafy trees, but some have a twiggy juvenile and others are twiggy all their lives. The same kind of variation occurs in other New Zealand plants such as kōwhai and ribbonwood.
This grown form is termed ‘divaricating’ and is a conspicuous feature in New Zealand. Some people think it might be related to evolving with the extinct bird moa, the twigginess protecting the plant from excessive damage. Others think it may be caused by cool and dry climates before the ice age, the dense branches and small leathery leaves being protection against drought or frost.