Oliver. — Vegetation of the Kermadec Islands. 



149 



VII. Geographical Distribution. 



(a.) The Species. 



In the list of pteridophytes and spermophytes given in this paper 114 

 species are admitted as indigenous to the Kermadec Islands. Of these, 

 76, or 67 per cent., are flowering-plants, and 38, or 33 per cent., ferns and 

 fern-allies. 



The 114 species are referred to 88 genera, belonging to 42 famiUes. The 

 flora is thus most fragmentary, and characteristic of oceanic islands, whither 

 plants are accidentally carried by ocean and air currents, and possibly other 

 means. Twelve species, or 11 per cent., are endemic. The age of the 

 island, therefore, will not be so great as that of Norfolk Island or Lord 

 Howe Island, where the proportion of peculiar forms is about one-fifth and 

 one-fourth respectively. 



The relations of the Kermadec Islands plants to those of Lord Howe 

 Island, Norfolk Island, New Zealand, Australia, and Polynesia are expressed 

 in the following table : — 



The fiist column shows the percentage of the different constituents to 

 the whole flora. The extensions of the plants to Lord Howe and Norfolk 

 Islands (one or both) are shown in the second column. " Australia" means 

 the eastern portion of the continent and Tasmania. Polynesia includes 

 New Caledonia. 



In the four central columns of the above table every species is taken 

 into account. If a species is endemic it is counted under the headings in 

 which its nearest related species falls. Thus Poa polyphylla. being closely 

 allied to P. anceps, a peculiar New Zealand form, is included in the 16 shown 

 under " New Zealand," and, as this number stands in a row by itself, it 

 signifies that 16 species of Kermadec Islands plants, or 14 per cent, of the 

 flora, are identical with or related to endemic New Zealand forms. Similarly 

 Rapanea Jcermadecensis, which is related to R. crassifolia, occurring in Norfolk 

 Island and Australia, is the species represented by the fifth row. The seventh 

 row of figures shows that five species of Kermadec Islands plants are identical 



