XXXII FLORA 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; Cyperacee, 7; moisture-loving Monocotyledons, 9; Monochlamydee, 8; Umbellifere 
and Composite 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, as Ruppia, Zannichellia, Atriplex, and their allies; Dodonea, Arenaria rubra, and Calystegia 
Soldanella, also affect coasts ;—d. 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 Composite, of which four have pappus; a facility for aerial transport, which loses its significance 
and weight from the fact that the species of Composite (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 
d. 19 of the species are Glumacee, including 
met in that most isolated area which they all inhabit ; 
seven Grasses and three aquatic Cyperacee (which latter have also been included under b). 
This large proportion of the lower Orders of Pheenogamic plants is in accordance with a general 
law of geographic distribution, but not the more intelligible on that account, for I cannot recognize 
in their 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-oceanie or aerial transport, as would account for their having 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 Tarawacum officinale. Of those not found 
either in Australia or South America, Carex stellulata and Pyrenaica, and Sparganium natans. 
* For some details upon the adaptation of various seeds to oceanic and aerial transport, see my Essay on 
the Geographie Distribution of the Plants in the Galapagos Archipelago.— Transactions of the Linnean Society, 
vol. xx. 
