426 



C. SKOTTSBERG 



and TJiamuoscris finds no better place, but to derive FitcJiia from an American 

 source seems little inviting. Another solution is, perhaps, in sight. Professor GUN- 

 XAR KRnr.MAX kindly told me that, to judge by the pollen morphology, Fitchia 

 may have to be removed from the Cichoriuui subfamily where J. D. HoOKER 

 placed it next to Dcudroscyis and where it has remained. 



There is in the Pacific Ocean no island of the size, geology and altitude of 

 l^aster Island with such an extremely poor flora and with a subtropical climate 

 favourable for plant growth, but nor is there an island as isolated as this, and 

 the conclusion will be that poverty is a result of isolation — even if man is re- 

 sponsible for the disappearance of part of the flora, it cannot have been rich; 

 the Marquesas Is., which have been inhabited longer, I believe, and formerly 

 had a large native population, still preserve a fairly rich and varied angiospermic 

 flora, half of which is endemic. The distances are too great to be overcome 

 except on very rare occasions. The nearest land is to the west, the small most 

 easterly islets of the Alangareva (Gambler) group, but winds (S.E. trade-wind) and 

 currents are unfavourable for transport from \V., and Piaster Island appears to lie 

 away from the cyclonic tracks. Beach drift is responsible for the arrival of several 

 s{)ecies, Ipoinaca, Caesalpijiia, Cheuopodium, Tciragonia, Eryt/iraea, Apium, Samo- 

 lus, LyciuDi and perhaps some grasses and species of Cypcrus, altogether about 

 ^'3 of the angiosperms. Storms bring light diaspores, but it is noteworthy that 

 CoDipositac are absent. I can find no special adaptations for bird carriage, but the 

 j)ossibility of rare cases of epizoic transport cannot be excluded. However that 

 may be, Piaster is a good example of an island peopled by "waifs and strays". 



Affinities are, as we have seen, with Malaysia-Australia or pantropical, whereas 

 the well-marked east Polynesian flora has contributed nothing, not even its leading 

 famil}' Rubiaceae, rich in drupe-fruited forms. Sophora torouiiro is allied to vS". ''tetra- 

 ptcrd^ of Raivavae and Rapa; I cannot tell if this is the true /^/r^//rr^, a native 

 of New Zealand, but I do not think it is, and as Brown's description (III. 120) 

 shf)ws, it differs much from toroniiro, which comes very close to S. masafuerana. 

 Neither is of American ancestry: sect. Edivardsia is austral-circumpolar and gene- 

 rallv regarded to be of Antarctic origin or, at least, history. 



With the exception of Lyciian carolinianiwi var. sa7idvicense, supposed to 

 belong to the beach drift, there is, if FitcJiia is definitely excluded, no American 

 element in the fiora of southeastern Polynesia, nor is it expected there. It is, as 

 we have seen, found in I^aster Island. Of the 3 endemic grasses, Stipa was ten- 

 tatively brought to the palaeotropical element, Axonopus to the neotropical. Dan- 

 tlionia is an austral-circum{)olar, tricentric genus. Three American, not endemic 

 si)ecies. Cypcrus rraj^rostis, Scirpus riparius and Polygomim acumiiiatmn, remain 

 to be accounted for. 



\'{ I^^aster Island once had a richer flora is an open question. According to 

 newspa[)er reports a palynological survey of the swamp in the crater of Rano 

 Kao was planned for IllA I.rdaiii/s recent survey. The thickness of the loose, 

 water-soaked Cauipylopus peat was not measured by me; it is a somewhat dan- 

 gerous quagmire which cannot be bored with the usual methods, but samples may 



