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PACIFIC SCIENCE, Vol. XIX, April 1965 
giving any impression of the relationships ex- 
isting among various Pacific island floras. 
The only locally endemic genera in the area 
under discussion are Loxsoma in northern New 
Zealand and Stromatopteris, a monotypic mem- 
ber of the Gleicheniaceae confined to the open 
serpentine region in the south of New Cale- 
donia. It is interesting that these occur in the 
two island groups with the longest geological 
history. 
SAMOA AND THE SOCIETY ISLANDS 
Similarities are most striking when the floras 
of Fiji, Samoa, and the Society Islands are 
compared with one another. Of the total of 
approximately 200 species in Samoa only 32, or 
16%, are endemic, and all of these are species 
closely related to other local species or to ones 
found in Fiji. A critical comparison of the en- 
demic species of the various Pacific islands is 
required because in the past there has been a 
marked tendency to give specific rank to any 
local form which varies at all from the de- 
scribed type, often on the basis of a single 
collection. This is most apparent in large and 
difficult genera such as Asplenium and Cyclo- 
sorus. The eight Samoan species with peculiar 
distribution and found nowhere else in Poly- 
nesia, as noted by Christensen ( 1943 ) , are all 
open to misinterpretation, each apparently 
being based on single, possibly aberrant, indi- 
viduals. Of the remaining non-endemic species, 
practically all are found in Fiji. 
The picture presented for Samoa is repeated 
with minor variations in the Society Islands. 
Here there are approximately 150 species of 
ferns of which 30% are regarded as endemic. 
This appears to be a somewhat high figure 
when it is noted that Tahiti is geogically 
younger than Fiji with only 20% of endemics, 
but it may be explained on the basis of the 
greater elevation of the former and its greater 
isolation. A more likely explanation when com- 
paring the percentage of endemics in these 
islands may lie in the relative propensities of 
the various authors to recognize local variants 
as true species. Again all of the Society Islands’ 
endemics are close to other local species or to 
species found elsewhere in Polynesia, and Cope- 
land (1932) admits that one, Polypodium 
maximum (Brack.) Hook., may be an inter- 
specific hybrid. This aspect of hybridism which 
is known to occur in some fern groups in New 
Zealand may explain several of the rare spe- 
cies which appear in so many Pacific island 
lists on the basis of a single collection. 
The remaining high island groups of south- 
ern Polynesia, the Cook Islands, Tonga, the 
Marquesas, and the Australs, have fern floras 
which are only extensions of the three major 
areas, Fiji, Samoa, and the Society Islands. 
FIJI 
Fiji represents possibly the immediate source 
of the fern flora of central and eastern Poly- 
nesia. Geologically it is older than these other 
islands and its flora is larger. However only 
just over 20% of this large number are en- j 
demic, and again all of these are closely related 
to other local species or to species on other i 
Pacific islands, including this time the New | 
Hebrides. Approximately 60% of the total spe- 
cies known in Fiji occur in these islands to the 
west, many extending as far as New Guinea 
and Indonesia. In addition to these common 
species, many pairs of closely related species 
occur in the southern islands of the New Heb- 
rides such as Aneityum and Fiji. Examples 
of these pairs of species are Humata botrychioi- 
des Brack, in Fiji and Humata multipda 
(Baker) Carr, ex Brownlie in the New Heb- 
rides, and Orthiopteris ferulacea (Moore) 
Copeland of Fiji and Orthiopteris kingii 
(Bedd.) Holtt. of the New Hebrides and far- 
ther west. 
The whole effect then of the fern floras of 
the islands from the New Hebrides eastwards 
into the Pacific is that of a Malaysian group 
becoming gradually depleted the farther east 
it is traced, with probable secondary centres 
of diversification in the New Hebrides them- 
selves and in Fiji. 
. 
NEW CALEDONIA 
Perhaps the most interesting island from a 
phytogeographical viewpoint is New Caledo- 
nia. This has been realised for many years in 
the case of the phanerogamic flora of that 
island, to judge by the number of publications 
