LECTURE III. 



THE DISTRIBUTION OF THE VEGETATION AND 

 FLORA OF NEW ZEALAND. 



By L. COCKAYNE, PH.D., F.L.S., F.N.Z.lNST., F.R.S. 



1. GENERAL REMARKS. 



The vegetation of New Zealand composed, as it is, of 

 numerous plant-associations varying in their characteristics 

 from subtropical to subantarctic and from hygrophytic to in- 

 tensely xerophytic, together with the species of diverse origin 

 (Palaeozelandic 1 , Malayan including Polynesian Australian 

 and Fuegian 2 ), offers excellent material for studies in plant- 

 distribution which should be of general phytogeographical 

 interest. Such studies, too, are simplified by the comparatively 

 small flora (about 1830 species of vascular plants) to be dealt 

 with, the somewhat less extreme complexity of the ecological 

 factors than that which botanical regions with an equally 

 diverse vegetation afford, and the clear-cut effect on distribu- 

 tion over a wide area of a sudden change in the rainfall. 



It need hardly be pointed out, that in the brief time allowed 

 by a lecture, only a quite incomplete sketch of the subject under 

 consideration can be presented, though it should be possible 

 to portray some of the more striking features of New Zealand 

 plant-distribution. 



The New Zealand Botanical Region includes not only New 

 Zealand proper (North Island, South Island, Stewart Island, 

 and the islets adjacent to these) but also the Kermadec Islands, 

 the Chatham Islands and the New Zealand Subantarctic Islands, 

 thus extending from lat. 29deg. 15min. S. to lat. 54deg. 30min. 

 S. (Macquarie Island). In this lecture, however, excepting 

 when illustrating certain points, distribution in New Zealand 

 proper is alone dealt with. 



Regarding the available material from which this lecture 

 is prepared, it might be objected that such is inadequate. New 

 Zealand, it may be argued, is far from being fully explored 

 botanically, so that the actual distribution of many species can- 

 not be known ; while, as so much of the primitive vegetation is 

 modified, or destroyed, it must be impossible to picture accur- 

 ately its primeval physiognomy and composition, or to trace its 

 distribution. Such objections are valid only to a minor degree. 

 It is true that much remains to be accomplished before a full 

 list of specific forms and complete details of their distribution 



! For explanation of this term see L,. Cockayne, " New Zealand Plants and 

 their Story," 2nd Edition, 1919, p. 205. 



2 - This is the Subantarctic South American element, but here called " Fuegian" 

 in qrder to avoid confusion with the New Zealand Subantarctic flora. 



