21 



number of them do not reach the PhiHppines proper but at most 

 extend in the south as far as western or central Mindanao and 

 in the north to Palawan or Mindoro only. Furthermore the 

 only genera known from and confined to Borneo and the 

 Philippines are Clemensia, Hallieracantha, Philbornea, and 

 Beccariardhiis. The Borneo-Philippine list then is much smaller 

 in species of limited distribution and very much smaller in genera 

 of such distribution than are the corresponding Philippine- 

 Celebes or Philippine-Molucca lists; and the flora of Celebes and 

 the Moluccas generally is no better known, and is perhaps less 

 perfectly known, than is that of Borneo. So far as the origin 

 of the Malayan element in the Philippine flora is concerned, the 

 preponderating evidence is that it has been derived from the 

 islands to the south and south-east of the Philippines rather 

 than from the nearer and apparently closer geographically 

 allied Island of Borneo. 



The Asiatic types in the Bornean fiora are chiefly if not 

 entirely those confined to the higher mountains. These species 

 probably reached Borneo during one of the glacial periods when 

 there was a more or less general migration of northern types to 

 the south. In former geologic times they may have occurred 

 in Borneo at lower altitude but now find the climatic conditions 

 to which they are adapted only at higher altitudes, notably on 

 Mount Kinabalu. Among these northern types may be mentioned 

 Viola serpens Wall., Potentilla (three species), Lactuca 

 retrosidens Merr., Aletris, Sanicula, Scirpus clarkei, Carex, 

 Gentiana (two species), Agrostis (two species), Poa epileuca Stapf, 

 and Deschampsia flexuosa Trin. The Asiatic element in Borneo 

 is com.paratively weak however, as compared with that of the 

 mountains of Java (which may be largely due to insufficient 

 exploration of Borneo) and especially in comparison with that 

 of the mountains of Northern Luzon. 



Perhaps the most interesting extra-Malayan element in 

 the Bornean fiora is the Australian one. This is not so pro- 

 nounced as is the same element in the Philippine flora, but again 

 this may be largely due to our own ignorance of the Bornean 

 flora due to insufficient exploration. The Australian types are 

 not confined to the higher altitudes although they are 

 predominatingly so, for Gsbornia octodonta F. Muell., and 

 Camptostemon (Vidalia) philippinense Becc. both occurring in 

 the mangroves are definitely Australian types; the former, a 

 monotypic genus was previously known only from the 

 Philippines and Borneo, and the latter presents two species, one 

 Australian, the other also previously known only from the 

 Philippines; Faradaya, of which one species has recently been 

 found in Borneo presents its other species in the regions to the 

 south-east of Borneo, New Guinea, Australia, and Polynesia. 



