3&XU FEOEA OF NEW ZEALAND. 



and 17 of these are not found in Australia, or elsewhere in the Old World. It is curious that none 

 of the latter belong to those peculiarly Arctic and north temperate genera mentioned in the note to 

 p. xxiv, except Caltha, to a southern form of which, however, the New Zealand species belongs. 



3. Plants common to New Zealand, Australia, and South America. — Of the 77 plants common 

 to these three countries, which include one-tenth of the flora of New Zealand, the majority are 

 Grasses, 10; Cyperacece, 7; moisture-loving Monocotyledons, 9; Monochlamydece, 8; Umbelliferce 

 and Composites each 4 ; and fully 50 of the whole number are also found in Europe, and do not 

 indicate any peculiar affinity between these three southern masses of land : of those that are not 

 European, some are Antarctic plants found in mountainous districts of Australia and Tasmania, as 

 Oxalis Magellanica. Of genera and species which, from their near affinity with one another, and 

 marked distinction from any others, may be said to be represented in all three countries, the majority 

 are Antarctic, and will be noticed under the fifth head. 



4. European plants in New Zealand. — These, amounting to 60, or about one-twelfth of the 

 whole flora, are in many respects the most interesting, and to their identification (which I consider 

 approximate only) I have given a great deal of care. Many I consider still open to inquiry, which 

 may reduce their supposed numbers ; but on the other hand I am sure that future discoveries will 

 add to them. To some extent these are distributed according to well-defined laws, which do accord 

 with facilities for migration by transport, thus: — a. 17 are sea-shore plants, or inhabitants of salt 

 marshes, zsRuppia, Zannichellia, Atriplex, and their allies; Dodoncea, Arenaria rubra, and Calystegia 

 Soldanella, also affect coasts; — b. 16 are fresh-water plants, or natives of very marshy spots, for 

 whose transport, however, it appears to me as difficult to account as if they were land-plants ; — c. 5 

 are Composites, of which four have pappus ; a facility for aerial transport, which loses its significance 

 and weight from the fact that the species of Compositce (which of all Orders is the largest and most 

 universal) are the most local. The fact of these five being found in so very many parts of the globe, 

 and being the only ones that are so, is extremely remarkable, for it points to oceanic transport as 

 the means of their diffusion : though the probabilities are against their all having thus accidentally 

 met in that most isolated area which they all inhabit; — d. 19 of the species are Glumacece, including 

 seven Grasses and three aquatic Cyperacece (which latter have also been included under b) . 



This large proportion of the lower Orders of Phamoganric plants is in accordance with a general 

 law of geographic distribution, but not the more intelligible on that account, for I cannot recognize 

 in then- structure or physiology any peculiarities that render them fitted for such diffusion*. And I 

 may add, that after a most careful microscopic study of the structure of the seeds of all the plants 

 common to Europe and New Zealand, I have come to the conclusion that, as a body, they present 

 no such facility for trans-oceanic or aerial transport, as would account for their baring migrated 

 further than the majority of other plants. To this may be added the fact that the Orders to which they 

 belong, are not those whose seeds after transport are found to vegetate most surely or freely in gardens. 



Many of the European species occurring in New Zealand are also Australian, Tasmanian, and 

 Antarctic; some of the more remarkable exceptions are, — of plants not hitherto found in South 

 America, Hierochloe borealis, Alopecurus geniculatus, some Carices, and other Monocotyledons. 

 Of plants not found in Australia, Agrostis canina and Taraxacum officinale. Of those not found 

 either in Australia or South America, Carex stelhdata and Pyrenaica, and Sparganium nutans. 



* For some details upon the adaptation of various seeds to oceanic and aerial transport, see my Essay on 

 the Geographic Distribution of the Plants in the Galapagos Archipelago. — Transactions of the Linnean Society, 

 vol. xx. 



