Included here is Vanuatu (formerly the New Hebrides) which forms a Y shaped archipelago in the South Pacific of more than 80 islands, the largest of which is Espiritu Santo. Up to about 600 m altitude lowland rainforest is the natural vegetation on the southeastern, windward sides of all Vanuatu islands. Important trees are Antiaris toxicaria, Castanospermum australe, Intsia bijuga and Kleinhovia hospitat. Endemic species include Alangium vitense (Cornaceae). On old volcanic ash, rich in plant nutrients, trees can reach more than 30 m in height with large crowns. Typical sub canopy trees include Diospyros acris, Garcinia pancheri and Syzygium species, while endemic small trees include various Veitchia palms, Calophyllum inophyllum (Clusiaceae) and Trilocularia pedicellata (Balanopsidaceae). These forests are best developed on the northern islands of Malakula and Espiritu Santo, and are structurally similar to forests on the Solomon Islands. However, many are in various stages of recovery following disturbance from hurricanes. Vines and epiphytes are numerous and certain areas are covered with lianas. The undergrowth includes various shrubs, and typically there is an herbaceous ground layer comprising genera such as Geophila and Homalomena and ferns like Asplenium, Microsorium and Pteris, but tree ferns are usually absent. Of endemic species, however, many seem to be specific to certain islands or island groups. On Aneityum, for example, there are endemic trees such as Boehmeria anisoneura (Urticaceae), Canarium aneityensis (Burseraceae), Couthovia neo-ebudica (Loganiaceae), Cryptocarya wilsonii (Lauraceae), Cupaniopsis aneityensis (Sapindaceae), Decaspermum neo-ebudicum (Myrtaceae), Dedea neo-ebudica (Saxifragaceae), Dolicholobium aneityense (Rubiaceae), Elaeodendron artense (Celastraceae), Endiandra aneityensis (Lauraceae), Ficus acrorrhyncha (Moraceae), Geissois denhamii  (Saxifragaceae), Grewia inmac (Tiliaceae), Guettarda kajewskii (Rubiaceae), Hedycaria neo-ebudica (Monimiaceae), Homalium aneityense (Samydaceae), Ixora aneityensis (Rubiaceae), Kermadecia lutea (Proteaceae), Leucosyke corymbulosa (Urticaceae), Ligustrum beo-ebudicum (Oleaceae), Litsia aneityensis (Lauraceae), Melia azedarach (Meliaceae), Myrtus aneityensis (Myrtaceae), Palaquium neo-ebudicum (Sapotaceae), Pittosporum aneityense (Pittosporaceae), Sideroxylon aneityense (Sapotaceae), Semecarpus tannaensis (Anacardiaceae), Sideroxylon aneityense (Sapotaceae), Syzygium aneityensis (Myrtaceae), Tieghemopanax neo-ebudarum (Araliaceae), Weinmannia macgillivrayi (Cunoniaceae), and the palm Kajewskia aneityensis (Arecaceae). Endemic shrubs in these rainforests include Cyrtandra aneiteensis (Gesneraceae), Elatostema macrophyllum (Urticaceae) and Psychotria aneityensis (Rubiaceae), while other endemics include epiphytes such as the orchid Eria kajewskii (Orchidaceae), the vine Faradaya neo-ebudica (Lamiaceae), and the parasites Loranthus aneityensis (Loranthaceae) and Medinilla neo-ebudica (Melastomaceae).

References

Ames, O. 1932. Contribution to the flora of the New Hebrides and Santa Cruz islands. Orchids collected by S. F. Kajewski in 1928 and 1929. Journal of the Arnold Arboretum, 13: 127-144.

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

Braithwaite, A. F. 1975. The phytogeographical relationships and origins of the New Hebrides fern flora.  Philosophical Transactions of the Royal Society of London, B272: 293-313.

Chew, W. L. 1975. The phanerogamic flora of the New Hebrides and its relationships. Philosophical Transactions of the Royal Society of London, B272: 315-328.

Dowe, J. L. & Cabalion, P. 1996. A Taxonomic Account of the Arecaceae in Vanuatu with descriptions of three new species. Australian Systematic Botany, 9: 1-60.

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

Guillaumin, A. 1931. Contribution to the flora of the New Hebrides. Plants collected by S. F. Kajewski in 1928 and 1929. Journal of the Arnold Arboretum, 12: 221-264.

Guillaumin, A. 1932. Contribution to the flora of the New Hebrides. Plants collected by S. F. Kajewski in 1928 and 1929. Journal of the Arnold Arboretum, 13: 1-29.

Guillaumin, A. 1932. Contribution to the flora of the New Hebrides. Plants collected by S. F. Kajewski in 1928 and 1929. Journal of the Arnold Arboretum, 13: 81-126.

Guillaumin, A. 1933. Contribution to the flora of the New Hebrides. Plants collected by S. F. Kajewski in 1928 and 1929. Journal of the Arnold Arboretum, 14: 53-61.

Guillaumin, A. 1938. A florula of the island of Espiritu Santo, one of the New Hebrides. Journal of the Linnean Society, London, 51: 547-566.

Balgooy, Van. M. M. J. 1969. A study of the diversity of island floras. Blumea, 17: 139-178.

Green, P. S. 1979. Observations on the phytogeography of New Hebrides, Lord Howe Island and Norfolk Island. In: Plants and Islands. Ed. D. Bramwell. Academic Press.

Krupnick, G. A. & Kress, W. J. 2003. Hotspots and ecoregions: a test of the conservation priorities using taxonomic data. Biodiversity and Conservation, 12: 2237-2253.

Moret, P., Veillon, J. M. & MacKee, H. S. 1984. Floristic relationships of New Caledonian rain forest phanerogams. In: Biogeography of the Tropical Pacific (Proceedings of a Symposium). Eds. F. J. Radovsky, P. H. Raven and H. Sohmer. Bishop Museum Special Publication No. 72.

Mueller-Dombois, D. & Fosberg, F. R. 1998. Vegetation of the Tropical Pacific Islands. Springer.

Setoguchi, H., Ohba, H. & Tobe, H. 1998. Evolution in Crossostylis (Rhizophoraceae) on the South Pacific Islands.  In: Evolution and Speciation of Island Plants. Eds. T. S. Stuessy &  M. Ono. Cambridge University Press.

Schmid, E. 1975. La flore at la végétation de la partie méridionale de l’Archipel des Nouvelles Hébrides. Philosophical Transactions of the Royal Society of London, B272: 329-342.

Schmid, M. 1978. The Melanesian forest ecosystems (New Caledonia, New Hebrides, Fiji Islands and Solomon Islands. In: Tropical forest ecosystems. Natural Resources Research Vol. XIV. UNESCO

Schmid, M. 1989. The forests in the tropical Pacific archipelagoes. In: Ecosystems of the World 14B - Tropical Rain Forest Ecosystems.  Elsevier.

Thorne, R. F. 1965. Floristic relationships of New Caledonia. University of Iowa Studies in Natural History, 20: 1-14.