Forest Vines to Snow Tussocks: The Story of New Zealand Plants
A full range of coastal habitats, from sand dunes to rocky cliffs, can be found in the Chatham Islands. A number of the species are the familiar plants of such sites on the New Zealand mainland, but there are also some notable endemics. Among these, certain large herbs once formed a band of lush vegetation at the top of many sandy and stony storm page 216beaches: the nettle Urtica australis, Embergeria (Sonchus) grandifolius and Myosotidium hortensia. M. hortensia, now widely cultivated, could be called a giant forget-me-not. The leaves, like those of Stilbocarpa in the su-bantarctic, are rhubarb-like and almost fleshy and the flowers in large heads are blue in the centre grading outwards to white. It is a plant stock find very palatable and is now quite rare. Today's sand dunes are dominated by the introduced marram grass.
Endemics of sea cliffs include Hebe chathamica, H. dieffenbachii and the grasses Poa chathamica and Festuca coxii. Myosotidium hortensia may still be found in inaccessible places. Dense shrubberies of Olearia chathamica may be prominent along cliff tops. A large, grey-green, remarkably soft-leaved Aciphylla, A. dieffenbachii, was formerly common along the southern cliffs of the main island and is still frequent on Pitt Island. A smaller species, A. traversii, is a plant of tableland bogs, but it, too, has been reduced by stock.
In highly fertile peaty places riddled with muttonbird burrows, grow luxuriant masses of Carex trifida and the endemics Leptinella featherstonii and Senecio radiolatus. Such sites are now confined to the smaller islands.
With their absence of groups of poor dispersal ability, particularly conifers, the Chathams have an isolated oceanic rather than a continental flora. New Zealand seems to be the principal source area but, as with the subantarctic islands, the presence of a significant element of distinctive endemics indicates quite a long period in isolation.