New Zealand plants – Introduction
Some New Zealand plants have an ancient lineage. Others are relative newcomers, and have evolved since New Zealand’s isolation. There are about 2,200 plant species native to New Zealand, 80% of these occur nowhere else.
White is the most common flower colour. There are over 220 trees native to New Zealand, only two are deciduous. Plants that are deciduous in the UK can be evergreen in New Zealand. For example speedwell is commonly seen as a blue flowered herb in lawns; but in New Zealand its cousin is an evergreen shrub called Hebe.
About 290 million years ago all land formed one supercontinent called Pangaea. This split into Laurasia and Gondwana, about 150 million years ago – Laurasia to the north; Gondwanaland to the south. Africa, India and Madagascar split from Gondwana about 130 million years ago. About 70 million years ago New Zealand finally split from Australia and Antarctica.
About 190–135 million years ago trees of the podocarp family were evolving, and spread throughout Gondwanaland. The southern beeches, Nothofagus, appeared 135–100 million years ago. Members of both families are found in New Zealand.
New Zealand was recently (in geological time) isolated from other landmasses.
We would therefore expect its flora to also show the features of the Isolated
Island Syndrome, which are:
1. Plants with good dispersal are strongly present
2. Plants with poor dispersal are absent.
The lack of specialised pollinators, such as bees, explains the general lack of highly coloured flowers, their small size and shallow forms. A similar pattern is seen in Hawaii, which is 2,500 miles from the nearest continent.
For more information on the evolution of New Zealand plants see the NZ Plant Species Radiation Group website.
The horticultural information on New Zealand native plants refers to growing conditions in the United Kingdom.
For a comparison between the flora of New Zealand and the British Isles see the Museums and Galleries of Northern Ireland website.
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