INTRODUCTION TO THE REPORTS ON INSULAR FLORAS. 2i> 



The number set down for Norfolk Island is probably too low, having been taken from 

 Endlicher's Prodromns (1833). Finally, we come to the New Zealand region, that is to 

 say, New Zealand and the adjacent islands included in Hooker's Handbook of the New 

 Zealand Flora. Eighteen genera and upwards of forty species have been discovered, and 

 two of the genera are endemic, while the rest are also Tasmanian or Australian ; none 

 extend to Southern America, the few genera there being distinct and mostly peculiar. 

 With one exception, Chiloglottis corni^ta in the Auckland Islands, which may yet be found 

 in New Zealand, the orchids found in the Kermadec, Chatham, Auckland, and Campbell 

 Islands, are New Zealand species ; a fact pointing to a former land connection. The 

 general distribution of orchids warrants this assumption, for there are comparatively few 

 genera of very wide range, and these, with few exceptions, are the terrestrial genera which 

 have their greatest concentration in the temperate zone of the northern hemisphere. Thus, 

 of the ten orchideous genera represented in California, eight are British, and a ninth, 

 Calypso borealis, is also found in Northern Europe and Siberia ; while only one is peculiar 

 to America. 



THE GENERAL AND INSULAR DISTRIBUTION OP THE GENERA 



CAREX AND UNG1NIA. 



Among large genera especially interesting on account of their insular distribution 

 is Carex, comprising about six hundred species, which are, perhaps, more widely dispersed 

 than those of any other genus of flowering plants ; and they grow in a very great variety 

 of situations, from the extreme polar limits of vegetation down to the most remote islands, 

 though within the tropics they are almost restricted to the mountains. Carex, too, is 

 the only one of the very large and widely dispersed genera that is represented in most 

 of the oceanic islands. Euphorbia is represented in Ascension and in many of the Pacific 

 Islands, and Cyperus in nearly all of the tropical islands ; but Carex occurs in a large 

 number of islands, both in the temperate and tropical zones, and in all three of the great 

 oceans. It may be interesting, therefore, to give some more definite particulars of the 

 o-eneral distribution of the species. A considerable number of the species are widely 

 spread, some very widely spread ; yet in almost all parts where these commoner species 

 penetrate, they are associated with local species. Those growing in the more remote 

 oceanic islands are mostly endemic in single islands or groups of islands. Thus, in the 

 Bermudas, there is one species, which is endemic ; in St Helena there are two, both 

 endemic ; in the Tristan da Cunha group there are two, both endemic ; in Juan Fernandez 

 the only species is endemic ; in the Sandwich Islands, three out of six are endemic ; and 

 of the twelve species found in the Azores six are endemic, and that, be it remembered, in a 

 flora containing a very small endemic element. On the other hand, the six which inhabit 



(BOT. CHALL. EXP. INTRODUCTION 1885.) 5 



