23 - 5 Dickerson: Bagnio Plateau 439 



south as Celebes and Timor. This indicates a very long period since the 

 original plants came into the Philippine Islands, allowing for the devel- 

 opment of very numerous endemic species and no less than six endemic 



If we examine the flora of the Benguet-Bontoc region by larger 

 groups, for example, families, we find two striking facts. The families 

 essentially characteristic of the temperate regions are relatively strongly 

 developed, while the families highly developed in tropical regions are very 

 poorly represented. Thus, such essentially temperate families as the 

 following seventeen are well represented in the Benguet-Bontoc region: 

 Pinaceas (one species of Pinus, Saxifragaceaa. 



but dominant). Rosacea?. 



Gramineae. Violaceaa. 



Cyperaceae. Ericaceae 



Juncaceae. Primulaceae. 



Liliaceaa. Gentianaeeaa. 



Caryophyllaceae. Labiataa. 



Ranunculaceae. Scrophulariaceaa. 



Berberidaceae. Compositaa. 



In contrast to this, the families that are in general strongly developed 

 at low and medium altitudes in the Philippines and in other tropical 

 countries are either entirely unrepresented in the Benguet-Bontoc region 

 or are represented only by few species, practically none of the few species 

 that do occur there being confined to the Benguet-Bontoc region. Perhaps 

 the most striking case is the Dipterocarpaceaa, the family being represented 

 in the Philippines by nine genera and about fifty species, and dominant 

 in the primary forests of the entire Archipelago at low and medium 

 altitudes. No representative of the family is known from the region 



Pandanaceae. Guttiferaa. 



Palm*. Dilleniaceae. 



Nyctaginaceae. Flacourtiaceaa. 



Anonaceaa. Lecythidaceaa. 



Myristicaceae. Combretaceae. 



Capparidaceae. Sapotaceaa. 



Connaraceae. Ebenacea?. 



Meliaceaa. Apocynaceaa. 



Sterculiaceaa. Convolvulaceae. 



Malvaceae. Verbenaceaa. 



Dipterocarpaceaa. Bignoniaceaa. 



Ochnaceae. Acanthaceaa. 



e the very numerous essentially tropical genera which 

 occur elsewhere in the Philippines but which do not occur at all or, 

 if present, then very poorly represented in the Benguet-Bontoc region. 



