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.

Vanuatu Vegetation of New Volcanic Surfaces

On Yasur Volcano on Tanna, the ferns Histiopteris incisa, Nephrolepis hirsutula and Cyathea species are widely but sparsely distributed on lava fields, but a completely different flora occurs on the disturbed cinder cones. Here the dominant species include shrubs such as Melastoma denticulatum, Piper latifolium and Pipturus argenteus, the grasses Imperata cylindrical and Miscanthus floridulus, and the annual herb Emilia sochifolia. Surprisingly orchids have also been recorded in these inhospitable areas including species of Spathoglottis, while on the volcanic ash of Erromango the endemic orchid Trichochilus neo-ebudidus (Orchidaceae) can be found.

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.

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.

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.

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.

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

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.