MISCELLANEOUS PLANTS 



207 



cavity, neither coats nor kernel having independent floating power. 

 Of some tested in Jamaica half were afloat after six and a half weeks 

 in sea- water, most of them with sound kernels. Schimper found 

 that seeds of D. viscosa floated from ten to sixty days (p. 165). 



In the Turks Islands this plant only came under my notice on 

 Grand Turk. There, in the company of Sophora tomentosa and of 

 plants peculiar to this region, it thrives in the sandy interior of the 

 southern part of the island, but does not appear on the beach. 



Dodoncea offers in its distribution much the same problem that 

 is presented by Cassytha and Sccevola as discussed in other pages of 

 this work. Here we have three genera, in great part Australian, 

 which are, however, represented over the warm regions of the globe 

 by one or two species typically littoral in their habit, but able in 

 the case of those of the first two genera to accompany xerophytic 

 plants far inland. Here we have a clue to distribution, which if 

 thoroughly investigated might lead to rich results, though it would 

 require many years of travel and research. It can only be said here 

 that my later inquiries in the West Indies go to confirm the general 

 inference given on page 341 of my previous work, namely, that in 

 the case of Dodoncea viscosa currents alone could not account for its 

 distribution in oceanic islands like Hawaii, and that if we placed 

 the agencies of dispersal in their order of effectiveness they would 

 be, first, granivorous birds, then the currents, and lastly man. 



It may here be observed that this plant was found established 

 on Krakatau in 1906. more than twenty years after the great eruption. 

 It was also noticed on the neighbouring coast of Sumatra (Ernst, 

 pp. 17, 40). As one of the plants of the old dunes it is found near 

 the coast all over New Zealand, and has also reached the Chatham 

 Islands (Cockayne's Report on the Dune Areas of New Zealand, 1911, 

 pp. 30, 33). 



ECASTAPHYLLUM BROWNEI, PerS. 



This small leguminous shore tree, which is not only widely dis- 

 tributed in the tropics on the American side of the Atlantic, but 

 occurs also on the West Coast of Africa, is one of the commonest 

 plants bordering the beach in these regions. It extends from 

 South Florida through the West Indies to Southern Brazil, and is 

 found on both the Atlantic and Pacific shores of Central America. 

 It is one of the plants that De Candolle regarded as at home in 

 America, but as naturalised in Africa. In West Africa, however, 

 it behaves as an indigenous tree ; and when we read in Dr. Vogel's 

 journal quoted in Hooker's Niger Flora, that with Chrysobalanus 

 icaco it forms the jungle that clothes the strand near the mouth of 

 the River Nun, we are reading of the association of two typical West 

 Indian shore trees or shrubs in tropical West Africa. Both of them 

 were viewed by De Candolle as American plants naturalised in Africa 

 {Giogr. Botan., p. 792) ; yet both of them would be quite unfitted, 

 as regards their fruits, to accomplish in an effective state the long 

 drift involved in the passage from the American to the African con- 

 tinent by the Gulf Stream route. The only Atlantic traverse avail- 



