Alpine Zone

Above the subalpine forest and in frosty hollows within it are tussock grasslands similar in appearance to those of the New Zealand mountains. However, no species of the snowgrass genus (Chionochloa) are present. Instead the tussocks belong to such grass genera as Poa, Deschampsia and Deyeuxia, also represented in New Zealand and many other parts of the world. Scattered through the tussock grassland are several shrubs including species of Coprosma, Gaultheria and Parahebe and small trees of Olearia spectabilis. In places clumps of the fern Papuapteris linedris intermingle with the tussocks and at lower elevations a distinctive species of tree fern (Cyathea atrox) is scattered throughout. Above about 4000 m there is a short grassland with species of Festuca and Poa as well as a number of dwarf shrubs. In poorly drained places there are swamps and bogs: the swamps dominated by grasses and sedges; the bogs by cushion plants and small shrubs. The cushion plants include Astelia papuana, Oreobolus pumilio and Carpha alpina. The last species also occurs in Australia and New Zealand.

Above about 4200 m species of Styphelia, Parahebe and Drapetes form close mats on rocky sites with small grasses and species of Ranunculus, Parahebe and Potentilla on level areas and in hollows.

The alpine flora of New Guinea is not rich in species and has links with both north and south temperate regions. An unusually high proportion, 30 per cent, of the species are found outside New Guinea.