258 E. D. Merrill 



more or less automatically accept it as a group characteristic of 

 that region. If a representative of it is later found in another 

 area, we are apt to consider it as an extraneous entity there. Euca- 

 lyptus is such a genus. It is tremendously developed in Australia, 

 has a very few species in New Guinea, and one which extends 

 to the Bismarck Archipelago, the Moluccas, Celebes, and the 

 Philippines. We are justified in accepting it as an Australian ele- 

 ment in the other regions. The same is true of the few phyllod- 

 inous species of Acacia outside of Australia. The one native 

 species of Ulmus in northern Sumatra, two species of Pinus in 

 Sumatra and the Philippines, and one species each of Taxus and 

 Gleditschia in the Philippines and Celebes may be unquestion- 

 ably accepted as Asiatic (continental) types in Malaysia. But 

 consider the following genera: 



The genus Vavaea was described in 1846 for a single species 

 from Vavau in the Tonga Islands. When the first Philippine 

 species was found, it was considered to be a Polynesian element 

 in the Philippine flora; and yet seven species are now known in 

 the Philippines, one in Java, three in New Guinea, one in the 

 CaroHne Islands, and still only three in Polynesia. This supposed 

 Polynesian element in the Philippines and Malaysia is really a 

 Malaysian element in Polynesia. Couthovia was even more 

 mistakenly located. This genus was proposed in 1858 for two 

 species, one from Hawaii and one from Fiji. In 1888 a third 

 species was described from New Guinea, and ten years later a 

 fourth from Celebes which, four years after, was found in the 

 Philippines. Thus we had a "Polynesian" element in the New 

 Guinea-Philippine-Celebes flora until the New Guinea flora be- 

 came better known. Eleven species of Couthovia are now known 

 from New Guinea and two from the Caroline Islands. Couthovia 

 thus resolves itself into a Papuan genus which has extended its 



