In contrast to the Mount Gede area, Mount Halimun has been comparatively little researched; the still strong conviction thet the mountainis haunted meant that early researchers found it very difficult to obtain guides.

The past geological link with South Sumatra is reflected in the vegetational affinity between the two areas. Over half the forest occurs in the altitudinal range 1,000-1,400 m. This can be regarded as sub-montane forest, a type which possesses a greater diversity of plants than higher, cooler areas. Dominant tree species are the huge rasamala (Altingia excelsa), the puspa (Schima walichii), and oaks (Lithocarpus). Smaller laurel trees (Litsea spp.) also make up an important constituent.

Epiphytes are numerous, orchids making a substantial contribution. Woody climbers, termed lianas, are well represented and include the very spiny rattans. The high rainfall gives rise to a rich community of ferns and mosses. Palms, rhododendrons, tree ferns and rare mistletoes all add to the area's high botanical value.

In the higher montane forest diversity is less, the dominant trees being conifers (Dacrycarpus imbricatus, Podocarpus blumeii and P. neriifolius). There are fewer herbs than in the sub-montane zone; even so, one investigation, lasting only a week, discovered 75 species of orchid. Many are rare, endangered or are Javan mountain endemics: Bulbophylum binnendykii, B. angustifolium, Coelogyre correa, Cymbidium ensifolium and Dendrochilium raciborski.

FAUNA

Mount Halimun is particularly important for Javan gibbon conservation. The gibbon (Hylobates moloch) lives in primary forest between sea level and 1,250 m. It ic confined to western Java. Since most lowland forest has been lost to agriculture, Halimun National Park offers a much-needed secure home. The Javan leaf monkey (Presbytis comata), our other] West Javan endemic primate, is also endangered. Its future will depend, crucially, on protection in forested National Parks. Halimun is also home to the ebony leaf monkey (Trachypithecus auratus.), which is found only on Java and few of the lesser Sunda Islands. The long-tailed macaque (Macaca fascicularis), common and famous throughout South East Asia, is also resident.

A quiet walk in the magnificent forest may yield views of wild pig (Sus scrofa) and barking deer (Muntiacus muntjak), the latter preferring secondary forest. These animals form the main diet for the now very rare wild dog (Cuon alpinus).

Flocks of bright red and black minivets fly through the canopy. In fact, there are around 130 species of bird, 90 of which are more or less permanently resident. Of the 30 or so "javanese endemics" nine can be seen within the park. At least two are endangered: the spotted crosias (Crosias albonotatus) and the rufous-fronted laughingthrush (Garrulax rufifrons). Other endemics include the pygmytit (Psaltria exilis); only found in West Java, it is the island's smallest bird.