Included here is the New Guinea Highlands which runs the length of the island. The highest peak is Mount Wilhelm at 4,509 metres.

Papuan Mountain Tree Fern Savanna

Savanna characterized by tree ferns appears to be unique to Papua New Guinea, and yet here it cover large tracts of land between altitudes ranging from 2700 – 3300 m and can be found on many of the high mountains.  The tree ferns are all atypical species of the genus Cyathea since most other members of this genus are forest dwellers characteristic of tropical mountain forests.  On Papua New Guinea, however, certain endemic species, such as Cyathea dicksonioides and C. pruinosa (Cyatheaceae) have broken away from this ancestral habitat becoming adapted to open grassland where they need to be tolerant of periodic burning, occasional draughts and large diurnal temperature fluctuations. This has been partly achieved by developing a thick fibrous ‘bark’, but these species are far from stunted and certain species, such as the endemic Cyathea muelleri can reach heights of 10 m. The dominant savanna grasses at these altitudes include the endemic or near endemic species Danthonia archboldii and Deschampsia klossi and to a lesser extent Dichelachne novoguineensis (Poaceae). Other endemic species include trees such as Dacrycarpus expansus (Podocarpaceae), various epiphytic shrubs such as Agapetes costata and Rhododendron caespitosum (Ericaceae), and many herbaceous species like Cynoglossum glabellum (Boraginaceae).

Papuan Alpine Grassland

Above the tree line at about 3900 m extensive grasslands occur. The species composition and structure of these grasslands can vary considerable with differences in altitude, soil depth, drainage conditions and degree of exposure, and may for example, range from stunted tussocks of Deschampsia klossii to a continous sward of Monostachya oreoboloides. Other grasses include species of Danthonia (such as D. archboldii, D. vestita, D. schneideri and D. semiannularis), Festuca (such as F. papuana) and Poa (such as P. callosa and P. crassicaulis). Sedges, including the endemic Carex bilateralis and C. sarawaketensis (Cyperaceae), may be present in some of the wetter area. Shrubs are also often present, but become scarce and mostly dwarfed to less than 20 cm above altitudes of about 4000 m. Dimorphanthera alpivaga (Ericaceae), Hypericum papuanum (Hypericaceae), Rhododendron pusillum and Vaccinium amblyandrum (Ericaceae) and Trochocarpa dekockii (Epacridaceae) are just a few of the endemic shrubs likely to be encountered. Small tree ferns, like the endemic Cyathea subtripinnata (Cyatheaceae) may also be encountered. Amongst the herbaceous elements are various endemic species of Epilobium such as E. detznerianum, E. hooglandii and E. keysseri (Onagraceae), while other endemic herbs include Geranium monticola (Geraniaceae), Potentilla irianensis (Rosaceae) and Trigonotis inoblita (Boraginaceae). Cushion herbs, like the endemic Oreomyrrhis azorellacea and O. papuana (Apiaceae), mosses, lichens and ferns abound in places sometimes having a a higher coverage than grasses. The fern Gleichenia vulcanica may in places be dominant up to about 4000 m, and the unusual endemic finger fern Papuapteris linearis (Dryopteridaceae) is often a conspicuous feature among tussock grasses on Mount Wilhelm.


Conn, B. J. 1995. Handbook of the Flora of Papua New Guinea. Vol. III. Melbourne University Press.

Henty, E.E. (ed). 1981. Handbook of the flora of Papua New Guinea. Vol. II. Melbourne University Press.

Paijmans, K. (ed). 1976. New Guinea Vegetation. Commonwealth Scientific and Industrial Research Organisation in association with the Australian National University Press, Canberra.

Polak, M. 2000. The botanical diversity in the Ayawasi area, Iran Jaya, Indonesia. Biodiversity and Conservation, 9: 1345-1375.

Robbins, R. G. 1971. The montane vegetation of New Guinea. In: World Vegetation Types.  Ed. S. R. Eyre. Macmillan.

Specht, R. L. & Womersley, J. S. 1979. Heathlands and related shrublands of Malesia (with particular reference to Borneo and New Guinea). In: Ecosystems of the World (9A) – heathlands and related shrublands: descriptive studies. Ed. R. L. Specht. Elsevier Science.

Steenis, C. G. G. J. van. 1957. Outline of the vegetation types in Indonesia and some adjacent regions. Proceedings of the Pacific Scientific Congress, 8: 61-97.

Womersley. J. S. (ed). 1978. Handbook of the flora of Papua New Guinea. Vol. I. Melbourne University Press.