xviii FLORA OF NEW ZEALAND. 
mate of the number of species known to botanists is a greatly exaggerated one*, and the prevalent 
ideas regarding their distribution no less contracted. 
Many more plants are common to most countries than is supposed; I have found 60 New Zea- 
land flowering plants and 9 Ferns to be European ones, besides inhabiting various intermediate 
countries; and amongst the lower Orders we find a greatly increased proportion of species common 
to all countries: thus of Mosses alone 50 are found in New Zealand and Europet; of Hepaticæ 13; 
of Algæ 45 are also natives of European seas; of Fungi nearly 60; and of Lichens 100. 
So long ago as 1814 Mr. Brown] drew attention to the importance of such considerations, and 
gave a list of 150 European plants common to Australia. The identity of many of these has re- 
peatedly been called in question, but almost invariably erroneously, added to which more modern 
collectors have greatly increased the list. 
The too prevalent idea that the plants of newly discovered, isolated, or little visited localities 
must necessarily be new, has been a fertile source of the undue multiplication of species. "There are 
very many cases of naturalists having been so impressed with this idea, that they have not thought it 
worth while to consult either books or herbaria before describing the plants from such spots. The 
New Zealand Flora presents several instances of this; two conspicuous ones oceur in the genus 
Oxalis; one, O. corniculata, is amongst the most widely diffused and variable plants in the world ; of 
its varieties no less than seven or eight species have been made, most of them supposed to be peculiar 
to New Zealand; not only is O. corniculata hence excluded from the flora, but in the descriptions of 
these its varieties, no allusion is made to that plant$. In the case of the other species the error is 
more excusable, and may be still open to question|| ; it is that of O. Magellanica, originally discovered 
in Fuegia, and imperfectly described by Forster, whose very indifferent specimens of it are in the 
* According to the loose estimate of compilers, 100,000 is the commonly received number of known plants : 
from a multiplicity of data I can come to no other conclusion but that half that number is much nearer the truth. 
This may well be conceived, when it is notorious that nineteen species have been made of the common Potato, and 
many more of Solanum nigrum alone. Pteris aguilina has given rise to numerous book species, Vernonia cinerea of 
India to fifteen at least. Many of the commonest European plants have several names in Hurope, others in India, 
and still others in America, besides a host of garden names for themselves, their hybrids and varieties, all of which 
are catalogued as species in the ordinary works of reference whence such estimates are compiled. 
+ In fact the distribution of some Cryptogams is so wide, that I have visited a spot in a high southern lati- 
tude, nearly all whose plants are not only identical with those of Great Britain, but inhabit many intermediate tem- 
perate and tropical countries. Cockburn Island, in lat. 64° 12’ S. and long. 64° 49' W., nearly fulfils this con- 
dition ; I thereon collected nineteen plants, of which three-fourths are natives of England. 
+ Appendix to Flinders's Voyage, vol. ii. p. 592. 
$ I have stated very confidently in the body of this work that eight of Cunningham's and Richard’s species of 
this genus are all referable to one. This view will probably not meet the approbation of the local botanists, who will 
point to the constancy with which some of the states retain their characters under varied conditions. I value such 
facts very highly, and attach great weight to them, and did these varieties occur only in New Zealand I should 
perhaps have withheld so strong an opinion on the subject; but such is not the case. 0. corniculata varies as much 
in numerous other parts of the world; and admitting, as every one must, that varieties are known to retain their 
characters with more or less constancy for certain periods, some other evidence is necessary to shake the opinion of 
the botanist who grounds his views on an examination of the plant from all quarters of the globe. 
|| As no identification is proved till all the organs of the plants to be compared have been studied, there is yet 
a possibility of these three species proving distinct, but I do not at all expect it; the only difference I can find is 
a greater obliquity and emargination of the petals of the New Zealand species, but that character varies so much 
both in this plant and in others of the genus that it loses all specific value. 
