DERIVATION OF THE FLORA OF HAWAII 25 



wind or of migratory birds ; and, second, certain genera allied to South 

 American types, which very possibly may be residual forms from an era 

 when there was a connection between South America through some ex- 

 tensive antarctic continent with New Zealand. 



4. The absence of conifers and such widespread genera as Ficus, 

 and a number of others which would be looked for on the assumption of 

 a continental origin for the archipelago, is perhaps due to their extinction 

 after the isolation of the islands. It is suggested that such extinction 

 may have been due to volcanic eruptions, to changes in soil conditions, 

 or ravages of disease. It is also possible that climatic changes may have 

 been concerned. 



AUSTRALASIAN-MALAYSIAN GENERA OCCURRING IN HAWAII, BUT NOT IN AMERICA 



Pittosporum Banks Pittosporaceae 



Elaeocarpus L Tiliaceae 



Byronia Endl Ilicaceae 



Pelea Gray ..Rutaceae 



Alectryon Gaertn. 21 ) c . , 



> bapmdc 



Dodonaea L. 22 



Colubrina L. 23 

 Alphitonia Reissek. 



y......... Rhamnaceae 



. ) 



Strongylodon \ogel } T 



~ > Legummosae 



Mezoneuron Desf. j 



Metrosidcros Banks ) ,, 



c . ~ > Myrtaceae 



Syzygium Gaertn. j 



Tetraplasandra A. Gray ~\ 



Reynoldsia A. Gray ^ Araliaceae 



Cheirodendron Nutt. 

 Gardenia L. 1 



Plectronia L. V Rubiaceae 



Coprosma Forst. J 



Scaevola L Goodeniaceae 



Cyathodes R. Br Epacridaceae 



Embelia Burm. | Myrsinaceae 



Suttoma Hook. J 

 Ochrosia Juss. 

 /4/y^rto R. Br. 



Cyrtandra Forst Gesneriaceae 



Myoporum Banks & Sol Myoporaceae 



Plectranthus V Herit. ) T , . . 



_, >- Labiatae 



Phyllostegia Benth. J 



Achyranthes L Amarantaceae 



Wikstroemia Endl Thymeliaceae 



SS - [ Apocynaceae 



r. J 



21 One cosmopolitan species. 



22 One cosmopolitan species. 



23 One cosmopolitan species. 



