CHAPTER XVIII 



THE ENIGMAS OF THE LEGUMINOS^ OF THE PACIFIC ISLANDS 



Leguminosae predominate in tropical littoral floras. The anomalies of their 

 distribution in the Pacific islands. They conform to no one rule of dis- 

 persal or of distribution. Strangers to their stations. The American home 

 of most of the Leguminous littoral plants. Summary. 



IT is my intention here to gather up some of the "ends "of 

 the great tangle presented by the Leguminosae in the Pacific. 

 When we look at the indigenous phanerogamic floras of Fiji, 

 Samoa, Tahiti, and Hawaii we find that the Leguminosae form 

 5 or 6 per cent, of the total in each of the three first-named groups, 

 and only about 2*5 per cent, in Hawaii. The paucity of Legu- 

 minosse in oceanic floras was long ago pointed out by Sir Joseph 

 Hooker, whose work forms the foundation of much of our know- 

 ledge of insular plant-life. This is emphasised by Mr. Hemsley in 

 his volume on the Botany of the " Challenger" Expedition (Introd. 

 p. 25), where he makes the very significant remark that the 

 Leguminosae are wanting in a large number of oceanic islands 

 where there is no truly littoral flora. The islands, however, here 

 more especially referred to, are those of the southern Atlantic and 

 Indian oceans, such as St. Helena, Tristan da Cunha, and Amster- 

 dam. It is especially true of New Zealand, where the Leguminosae 

 barely make 2 per cent, of the total. Of the Polynesian islands, as 

 he points out, it is not so correct ; and, in fact, the proportion found 

 in the Fijian, Samoan, and Tahitian floras, respectively, is much 

 the same as that which characterises the British flora, namely, 

 5 to 6 per cent. 



When we come to explain the paucity of the Leguminosae 

 in the Hawaiian flora we bring to light the singular principle that 

 Leguminosa are far more characteristic of the littoral flora than of 



