CHAP. XXII THE FLORA Of* NEW ZEALAND 501 



shown, a moist and luiiforni climate favours the extension 

 of tropical forms in the temperate zone, yet some means 

 must be afforded them for reaching a temperate island. On 

 carefully going through the Handhooh, and comparing its 

 indications with those of Bentham's Flora Australicnsis, I 

 find that there are in New Zealand thirty-eight thoroughly 

 tropical genera, thirty-three of which are found in 

 Australia — mostly in the tropical portion of it, though a few 

 are temperate, and these may have reached it through New 

 Zealand.^ To these we must add thirty-two more 

 genera, which, though chiefly developed in temperate 

 Australia, extend into the tropical or sub-tropical portions 

 of it, and may well have reached New Zealand by the 

 same route. 



On the other hand we find but few New Zealand genera 

 certainly derived from Australia which are especially 

 temperate, and it may be as well to give a list of such as 



^ The following are the tropical genera common to Xew Zealand and 

 Australia : — 



1. Melicope. Queensland, Pacific Islands. 



2. Eugenia. Eastern and Tropical Australia, Asia, and America. 



3. Pnssiflora. N.S.W. and Queensland, Tropics of Old World and America. 



4. My} sine. Tropical and Temperate Australia, Tropical and Sub-tropical regions. 

 .5. Sfipota. Australia, Norfolk Islands, Tropics. 



6. Cyathodes. Australia and Pacific Islands. 



7. Parxonsia. Tropical Australia and Asia. 



8. Gfniostoma. Queensland, Polynesia, Asia. 



9. Mitrasacme. Tropical and Temperate Australia, India. 



10. Ipomoea. Tropical Australia, Tropics. 



11. Mazus. Temperate Australia, India, China. 



12. Vitex. Tropical Australia, Tropical and Sub-tropical. 



13. Pisonia. Tropical Australia, Tropical and Sub-tro]iical. 



14. Alternanthera. Tropical Australia, India, and S. America., 



15. Tetranthera- Tropical Australia, Tropics. 



16. Santalum. Tropical and Sub-tropical Australia, Pacific, Malay Islands. 



17. Carumbinm. Tropical and Sub-tropical Australia, Pacific Islands. 



18. Elatoatemvia. Sub-tropical Australia, Asia, Pacific Islands. 



19. Pejycromia. Trojiical and Sub-trojiical Australia, Tropics. 



20. Piper. Tropical and Sub-tropical Australia, Tropics. 



21. Dacnjdium. Tasmania, 3Ialay, and Pacific Islands. 



22. Dammara. Tropical Australia, Malay, and Pacific Islands. 



23. Dendrohium. Tropical Australia, Eastern Tropics. 



24. Bolhophyllum. Tropical and Sub-tropical Australia. Tropics. 



25. Sarcochilns. Tro]iical and Sub-tropical Australia, Fiji, and Malay Island?. 



26. Freycinetia Tropical Australia, Tropical Asia. 



27. Cordyline. Trojiical Australia, Pacific Islands. 



2S. Dianella. Australia, India, Madagascar, Pacific Islands. 



29. Cyperus. Australia, Tropical regions mainly. 



30. Fimbristylis. Tropical Australia, Tropical regions. 



31. Paspalum. Tropical and Sub-tropical gi-asses. 



32. Isachne. Tropical and Sub-tropical glasses. 



33. Sporobolus. Tropical and Sub-tropical grasses. 



