V THE FIJIAN STRAND-FLORA 45 



tions. One can say that almost without exception the seeds or 

 fruits or seedlings of the mangrove and intermediate formations 

 float for long periods. In the case of some of the true mangroves, 

 as in Rhizophora and in Bruguiera, where germination takes place 

 on the tree, it is the seedling that floats, whilst in others, as in 

 Carapa and Lumnitzera, it is the seedvessel that floats. The 

 plants with non-buoyant seeds or fruits that belong to the littoral 

 flora are all confined to the beach formation, but they do not form 

 more than a sixth of the total. Almost all the " good floaters " of 

 the beach-plants are widely spread over the shores of the Pacific 

 and of much of the tropics, and include such familiar species 

 as Barringtonia speciosa, Caesalpinia Bonducella, Terminalia 

 Katappa, and many others mentioned in the lists of Notes 2 

 and 24. 



When, however, we come to the dozen or so of beach-plants 

 that possess seeds or fruits with little or no floating power, we find 

 that several of them have a limited distribution in the Pacific, such 

 as Acacia laurifolia, Drymispermum Burnettianum, Eugenia Richii, 

 &c., whilst others, such as Casuarina equisetifolia, Tephrosia pisca- 

 toria, Triumfetta procumbens, and Wikstroemia fcetida, are widely 

 spread. This small non-buoyant group of the beach-plants has a 

 nondescript appearance, and it is here that the inland flora is most 

 likely to make its influence felt by additions to the number. It is 

 here indeed that the littoral floras of the tropics mostly differ, the 

 accessions from the inland flora varying in each region. It is in 

 fact the zone of change. 



A number of these plants, such as the species of Drymispermum, 

 Eugenia, and Wikstroemia, have probably been dispersed by frugi- 

 vorous birds ; whilst others, like Triumfetta procumbens, possess 

 fruits that might have been transported in birds' plumage. From 

 the frequency with which Tephrosia piscatoria is associated on 

 hilltops in Fiji with Fagrasa Berteriana and climbing species 

 of Morinda that are well suited for dispersal by frugivorous birds, 

 it seems likely that it is also distributed by birds fond of a drier 

 diet. It is possible that the Polynesians, who much value the wood 

 of Casuarina equisetifolia, have often assisted in dispersing the tree. 



The following is a summary of the contents of the chapter. 



(i) The extension inland of the Fijian strand-flora is to be 

 attributed to the xerophilous organisation of the plants, and to the 

 exceptionally favourable conditions that are offered to such plants 

 on the plains, and in other scantily vegetated localities, lying 

 usually on the drier sides of the larger islands. 



