302 
PACIFIC SCIENCE, Vol. IV, October, 1950 
PLANT GROUP 
NUMBER OF 
SPECIES 
PERCENTAGE OF 
VASCULAR PLANTS 
REPRESENTED 
BY GROUP 
Compositae . . . 
. . 221 
14.1 
Ferns 
. . 138 
8.8 
Cyperaceae .... 
. . 119 
7.6 
Scrophulariaceae . 
. . 113 
7.2 
Gramineae .... 
. . 113 
7.2 
Umbelliferae . . . 
. . 62 
3.9 
Orchidaceae . . . 
. . 57 
3.6 
Ranunculaceae . . 
. . 50 
3.2 
Rubiaceae .... 
. . 47 
3.0 
Epacridaceae . . . 
. . 31 
2.0 
Onagraceae . . . 
. . 31 
2.0 
Leguminosae . . . 
. . 26 
1.7 
Juncaceae .... 
. . 25 
1.6 
Boraginaceae . . . 
. . 25 
1.6 
The differences between the figures for 
New Zealand and those for Australia are 
very striking: Leguminosae, ranking first in 
Australia, is not among even the first 10 of 
the families of New Zealand, and neither is 
Myrtaceae (in second place in Australia), 
Proteaceae (in third place), or Euphorbi- 
aceae (in eighth place). The Compositae, 
however, have achieved first place in the 
New Zealand flora (they are in fourth place 
in Australia), and — the ferns being left out 
of consideration — the Scrophulariaceae, the 
Umbelliferae, the Rubiaceae, and the Ranun- 
culaceae have entered into the list of fam- 
ilies with the most species. The Labiatae, in 
contrast, are not to be found at all in New 
Zealand; they did not reach these islands 
from Malaysia and Australia. 
Of the 1,591 plant species found in New 
Zealand, 428 species are not endemic. Among 
these, 366 are related to the Australian flora, 
and 108 are related to that of South America. 
The genera with the greatest number of 
species in New Zealand are these: Vero- 
nica, 84 species; Carex, 54; Celmisia, 43; 
Coprosma, 40; Ranunculus, 38; Olearia, 35; 
Senecio, 30; Epilobium, 28; Poa, 25; My- 
osotis, 23; and Hymenophyllum, 20. 
It cannot be said, however, that New 
Zealand’s flora is more primitive or has more 
primitive species than does the flora of Aus- 
tralia, even though its isolation from Malay- 
sia and New Guinea apparently occurred 
earlier than did that of Australia. The great 
number of endemics in New Zealand’s flora, 
then, can be attributed not to the conserva- 
tion of primitive species, but rather to the 
formation of new ones. 
Because of its temporary connection with 
Australia, Melanesia, and the Antarctic con- 
tinent, New Zealand cannot give us any 
assistance in solving the problem of the origin 
of the larger and older Australian flora, so 
important in any estimation of the age of 
the angiosperms. The geologic and biologic 
records left on New Zealand are quite dif- 
ferent from those of Australia, and they 
can not be traced very far back into geologic 
time. 
ORIGIN OF NEW TYPES IN AUSTRALIA 
How, then, can we explain the appearance 
of new types in Australia? Perhaps the fol- 
lowing supposition may be the simplest one. 
Let us assume that during the Upper 
Cretaceous period, or possibly during the 
Middle Cretaceous period, but in any case a 
short time before Australia’s geographic iso- 
lation began, there existed the plant types 
A, B, C, D . . . in Malaysia as well as in 
Australia . Since that time, the Malaysian 
types have evolved into types A 1 , B 1 , C 1 , D 1 
. . . that is, into new and different species or 
genera. The Australian types, however, have 
developed into types A 2 , B 2 , C 2 , D 2 . . . into 
different species or genera from both their 
parent types, A, B, C, D . . . and the col- 
lateral types A 1 , B 1 , C 1 , D 1 . . . developing 
in Malaysia. It is conceivable that the en- 
demic plants in Australia have evolved in 
this manner. 
Of course it is also possible that this 
development of endemics could have taken 
place in later times, without it being neces- 
sary for us to conclude that all species of 
the parent series A, B, C, D. . . must have 
been distributed throughout Malaysia and 
