44 



The prominence of orchids, Myrtacese, Rhododendrons, Styphelias, and 

 Vacciniums, in relation to other plants, is equally emphasized, but members 

 of the Araliacese, an old type of plant so prominent in the Arfak of New 

 Guinea, are, so far as we know, absent on the N. Bornean mountain. 



From descriptions of the Philippine mountain-ridge vegetation it would 

 appear that the Papuan facies again predominates, thus approximating it to 

 that of the Arfak and Mt. Kinabalu, the absence of araliaceous types being 

 less marked, though of the typical P;ipuan genera Anomopanax is represented 

 by one species, and Kissodendron and Mackinlaya are absent. Phyllocladu* 

 hypophyllus is common to all, with allied Dacrydium and Podocarpus spp. 

 Glochidion Merriltii is also common to the Arfak, but a thinning out in the 

 number of Styphelia and Vaeciniuni spp. is apparent, while the Rhododendrons 

 show a great reduction in variety of type. 



4. THE MOUNTAIN FOREST FLORA OF THE ARFAK MOUNTAINS 

 POSSIBLY REPRESENTS OLDEST PAPUAN TYPE. 



It is in the Arfak alone, of all the Papuan mountain ranges of similar or 

 greater altitude, that two different localities have been worked over on three 

 separate occasions. This fact gives a wider field of comparison in relation 

 to this range. On comparing the general type of vegetation and the 

 generic and specific distinctness of the plants so far collected on this range 

 with those known from similar localities, one feels inclined to look upon 

 these granite mountains as carrying an older part of the Papuan flora. 

 Where so little is known, however, of the mountain flora of the country as 

 a whole, and collections remain limited to vertical sequence, it is impossible 

 to base such an impression on any actual fact, and the hypothesis is only 

 worth advancing as a possible consideration for future workers. 



The contrast is very striking between the recent " korang " belt, from 

 which this range on the east rises almost without transition as abruptly as 

 the mountains on the north from the sea, and the well-defined limits and 

 deep soil of the foot-hills and lower ranges. The extreme homogeneity of 

 the mountain forest zone, the extraordinarily small incidence of outside or 

 immigration plants, combined with the relatively broad crests of the ridges 

 and the tremendously weathered condition of the main range, are all facts 

 which point to general stability in condition, spreading over a considerable 

 epoch of time. 



The climate of the Arfak would also seem to be more favourable than on 

 other ranges, and the nature and structure of the plants are not so limited 

 by the edaphic and atmospheric factors which play such a large part in the 

 restriction of floral conditions on Kinabalu. 



For instance, all the Arfak plants show coriaceous to very small leaves, 

 and the hairy covering or tomentum, common to many of the Kinabalu 



