Geographical Affinities of Fern Floras— Brownlie 
221 
on and references to the subject. An analysis 
of the fern flora reveals a corresponding diver- 
sity which contrasts markedly with the rather 
uniform Malaysian relationship of the floras of 
the other tropical Pacific islands. Of the ap- 
proximately 300 species 127, or nearly 42%, 
are endemic. This is a very high proportion of 
plants belonging to such an old group to be 
confined to one island, and can only be ex- 
plained on the basis of the presence of a land 
mass somewhere in the region for a much 
longer period than is the case for the other 
island groups discussed. Fournier (1874) pos- 
tulated a greater Melanesia somewhere in this 
area as a source of much of the Mew Cale- 
donia pteridophyte flora. 
In addition to this the appearance of the 
flora is not so overwhelmingly that of the wet 
Malaysian type found in the other islands. At 
least a quarter of the endemic species are truly 
distinctive, and not merely local variant spe- 
cies of genera such as Asplenium which ap- 
pear to have undergone recent evolution and 
speciation. The presence of several species in 
ancient groups like the Schizaeaceae and the 
Gleicheniaceae suggests relic forms from a 
much older period of diversification. Much in- 
terest also lies in the large number of en- 
demic species belonging to the Lindsaeoid 
group of ferns. Cytological investigations on 
this group suggest that it possibly consists of 
two sections— one a fairly ancient group di- 
versified from one another as to chromosome 
numbers (n = 34, 42, 47), and a fairly uni- 
form group with a chromosome complement 
based on rr ='50 which is typically Malaysian 
in distribution. It appears likely that the non- 
endemic species in Mew Caledonia belong to 
the latter, while the large number of taxonomi- 
cally difficult local species are older forms 
which may not be even closely related to the 
widespread ones. It is also significant that most 
endemics of all the old groups are confined to 
the poorer soils of the island and to mountain 
ridges, while the more aggressive widespread 
recent Malaysian forms occupy the rain forests 
and the better soils. 
A third element enters to a minor degree 
into the New Caledonian flora. This is the 
small group of species which are directly re- 
lated to those of eastern Australia, although 
they are possibly indirectly also Malaysian. The 
various species of Cheilanthes would fall into 
this category. Some of these species occur in 
Malaysia but not in the humid equatorial re- 
gion north of New Caledonia. Others are spe- 
cifically Australian derivatives of this group. 
NEW ZEALAND 
The final major region in the South Pacific 
is New Zealand. Here the number of species 
is considerably less than that of New Caledonia, 
Fiji, or Samoa, being approximately the same 
as that for the most easterly sizeable group, the 
Society Islands. However, a comparison of the 
two fern floras shows major differences. Where- 
as the Society Islands possess no endemic gen- 
era, New Zealand has the local Loxsoma and 
an elaboration of ancient groups only surpassed 
in New Caledonia. A further similarity with 
New Caledonia is shown by the fact that the 
three local species of Lindsaea ( L . linearis Sw., 
L. trichomanoides Dry., and L. viridis Col.) are 
cytologically distinct from one another. It seems 
possible that on the basis of their chromo- 
some contents the rather Isolated genera Lox- 
soma and Leptolepia are more nearly on the 
same evolutionary level, and possibly more 
nearly related to this old section in the Lind- 
saeoid group of ferns than to any other 
(Brownlie 1961, and unpublished). 
At least one third of the New Zealand spe- 
cies are endemic, but here the relationships of 
these endemics are not with the tropical Malay- 
sian element of the Pacific but most frequently 
with closely related species in eastern Austra- 
lia. This relationship is so close that somewhat 
more than 50% of the total New Zealand fern 
flora is found also in the southeastern part of 
Australia and Tasmania (Brownlie, 1962b). 
THE 'ANTARCTIC’ ELEMENT 
A theory which has been made much of by 
Copeland (1939 and 1947) is the antarctic 
origin of much of the world’s modern fern 
flora. This theory was based on his belief that 
within different genera those showing the most 
primitive morphological characters were those 
species occurring in southern lands. The evi- 
