Chathamian Sand Dune Vegetation

Just above high tide the sandy shores are characterized by the presence of small rosettes of Ranunculus acaulis and the cosmopolitan Calystegia soldanella together with occasional plants of the magnificent endemic Myosotidium hortensia (Boraginaceae). On the mobile dune ridges Festuca littoralis is the dominant species while in the more landward dunes the main sand binding species area Carex pumila, Primelea arenaria and Scirpus frondosa. In their undisturbed state, the more landward dunes support dune forest and scrubland chiefly comprising the endemic Myrsine chathamica (Mrysinaceae) and Olearia tranversii (Asteraceae) together with occasional plants of the impressive endemic purple flowered giant sowthistle Embergeria grandifolia (Asteraceae). However, this species tends to occur in more abundance on sand covered maritime cliffs and rocks where it can be found growing with the endemic Agropyron coxii (Poaceae).


Chathamian Maritime Rock Vegetation

In the soil filled crevices of rocks above the shoreline Crantzia lineata, Samolus repens and Triglochin striatum are usually the main species, but where the soil is less developed the endemic Senecio radiolatus (Asteraceae) becomes the more characteristic species. On maritime cliffs, the endemic Veronica chathamica (Scropulariaceae) seems to be able to grow on almost solid rock, while in other places there are luxuriant stands of Mesembryanthemum australis accompanied by Apium australe, Salicornia australis and the endemic Geranium traversii (Geraniaceae).


Chathamian Peatland Vegetation

A dense mat of Mesembryanthemum australe often covers open areas of peat, but this is frequently interrupted, especially in the wetter areas by patches of species such as Cotula muelleri, Pratia arenaria and Selliera radicans. In the dryer areas the endemic Cotula featherstonii (Asteraceae) can be found especially in areas that have been manured by mutton-birds.


Chathamian Limestone Cliff Vegetation

Veronica dieffenbachii, usually with its thick stem embedded in a crevice, is one of the characteristic species of these steep cliffs. Associated species include Phormium tenax, Senecio lautus and the endemic Linum monogynum var. chathamicum (Linaceae).  In some of the dryer areas white flowers of the endemic Geranium traversii (Geraniaceae) can also be found.


Chathamian Limestone Sophora Forest.

In limestone hollows, small woodlands characterized by the endemic Sophora chathamica (Fabaceae) can be found. Other dominant trees include the endemic Plagianthus chathamica (Malvaceae) and Pseudopanax chathamicus (Araliaceae). In fact, most of the trees found in these woodlands, including Coprosma chathamica (Rubiaceae) and Corakia macrocarpa (Cornaceae) are endemic to these islands.


Chathamian Lowland Forest

With possibly one or two exceptions most of the lowland trees are evergreen and most of them including Olearia traversii (Asteraceae), Coprosma chathamica (Rubiaceae), Corokia macrocarpa (Argophyllaceae), Hymenanthera chathamica (Violaceae), Mrysine chathamica (Myrsinaceae), Plagianthus chathamicus (Malvaceae), Pseudopanax chathamica (Araliaceae) and Veronica gigantea (Scrophulariaceae) are endemic or near endemic. Also scattered in these forest, often rising well above the canopy, is the endemic palm Rhopalostylis baueri (Arecaceae). On the edges of the forest, especially in some of the wetter areas, the endemic Dracophyllum arborea (Epacridaceae) and Senecio (Brachyglottis) huntii (Asteraceae) can occur in great abundance. Dracophyllum is of interest in that it goes through a broad-leaved juvenile form, which eventually changes into a needle-leaved adult form. This is thought to be an adaptation to strong winds.  Tree ferns such as Cyathus dealbata, C. medullaris, Dicksonia antarctica and D. squarrosa often dominate the forest undergrowth, and these in turn support many epiphytes such as the primitive Tmesipteris tannensis, and ferns such as Aspidium capense and Polypodium billardieri. Ferns are also a conspicuous feature of the forest floor with species like Asplenium bulbiferum, Lomaria lanceolata and Hymenophyllum demissum commonly occurring, and where there is a deep humus layer, orchids such as Acianthus sinclairii and Pterostylis banksii can be found.


Chathamian Tableland Forest

The most abundant trees of this formation are the two endemics Dracophyllum arborea (Epacridaceae) and Senecio (Brachyglottis) huntii (Asteraceae). The latter often providing spectacular displays of yellow blossoms.  Most of the remaining trees are also endemic including Coprosma chathamica (Rubiaceae), Corokia chathamica (Cornaceae), Myrsine chathamica (Mrysinaceae), Pseudopanax chathamica (Araliaceae) and Veronica gigantea (Scrophulariaceae). The lower tree layers are mainly dominated by the tree ferns Dicksonia antarctic and D. sqarrosa, and the whole lower forest is covered in epiphytic species especially filmy ferns such as Hymenophyllum multifidum, H. dilatatum and Trichomanes venosum.


Chathamian Swamp Formations

The curious restiaceous plant Leptocarpus simplex often dominates the swamps, which are largely confined to the central and northern parts of Chatham Island. These are also no doubt the places to find the endemic carices Carex chathamica and C. ventosa (Cyperaceae). In the slightly dryer areas, less likely to be subject to seasonal flooding, Coprosma propinque is usually the main species together with tall grasses such as Arundo conspicua, several Epilobium species and the endemic Astelia chathamica (Asteliaceae).


Chathamian Heath

In areas too exposed to wind for tree growth a type of heath develops. In the dryer areas Isolepis nodosa, Leucopogon richei, Libertia ixioides, Pimelea arenaria and the endemic Cyathodes robusta (Ericaceae) are the characteristic species. Libertia ixioides, imparticular, can form very large patches, and occasionally intermixed with this species are stunted plants of the endemic Dracophyllum paludosum (Epacridaceae). In other places, the bracken Pteris esculenta forms extensive stands, but where the bracken is not too tall species such as Dichelachne crinita, Lagenophora forsteri, Microtis porrifolia, Oreomyrrhis colensoi and Thelymitra longifolia can found growing among the fronds.


Chathamian Bog Formations

On some of the marshy land adjacent to lakes can be found the endemic Aciphylla traversii (Apiaceae), but in general the bog formations can be roughly divided into Sphagnum bogs, Lepyrodia-Olearia bogs, Phormium bogs and Dracophyllum bogs. The remaining Sphagnum bogs are considered to be very primitive and thought to have been much more extensive in the past. In the wettest areas the only associated taxa are usually Carex and Isolepis, but in the dryer areas scattered plants of Hierchloe redulens and the endemic Poa chathamica (Poaceae) occur. Hollows between the Sphagnum are the haunt of insectivorous plants such as Drosera binata and Utricularia monanthos and in places the unusual fern Schizaea fistulosa can be found. The Lepyrodia-Olearia formation seems to be the natural succession from Sphagnum bog as the ground becomes dryer. The two main species are Lepyrodia traversii and the endemic Olearia semidentata (Asteraceae). The former species was also thought to be endemic but has since been found in New Zealand. Other associated plants include Gleichenia circinata and the endemic Gentiana chathamica (Gentianaceae). In areas too dry for Olearia semidentata, its close relative the endemic Olearia chathamica (Asteraceae) may become the main species. This species can form dense thickets devoid of other plants, but where it is less dense species such as Lomaria procera and Pteris esculenta grow in the undergrowth. The remaining Phormium bogs are mainly confined to the banks of the tableland streams. The dominant Phormium tenax is often associated with species such as Cotula asiatica and Juncus planifolius. The Dracophyllum formation is transitional vegetation between bog and forest. It is characterised by the endemic Dracophyllum paludosa (Epacridaceae), but small trees of the related endemic Dracophyllum arboreum may also be present. The endemic Olearia semidentata (Asteraceae) may also be well represented and in places becomes the dominant species. The ground flora includes species such as Pratia arenaria and the endemic Poa chathamica (Poaceae).

Further information required.



Balgooy, Van. M. M. J. 1960. Preliminary plant geographical analysis of the Pacific. Blumea, 10: 385-430.

Cockayne, L. 1958. The Vegetation of New Zealand. H. R. Engelmann (J. Cramer).

Cockayne, L. 1902. A short account of the plant-covering of Chatham Island. Transactions of the New Zealand Institute, 34: 243-325.

Molloy, L. 1994. Wild New Zealand. The MIT Press, Cambridge, Massachusetts.

Northcroft, E. F. 1975. Adventive flora of the Chatham Islands. New Zealand Journal of Botany, 13: 123-129.