Australian Natural Orders--Dilleniaceae,
Buettneriaceae, Polygaleae, Tremandreae, Casuarineae, Haemodoraceae, and
Xyrideae are entirely wanting in New Zealand, and several others which are
excessively abundant and highly characteristic of the former country are
very poorly represented in the latter. Thus, Leguminosae are extremely
abundant in Australia, where there are over 1,000 species belonging to
about 100 genera, many of them altogether peculiar to the country; yet in
New Zealand this great order is most scantily represented, there being only
five genera and thirteen species; and only two of these genera, Swainsonia
and Clianthus, are Australian, and as the latter consists of but two
species it may as well have passed from New Zealand to Australia as the
other way, or more probably from some third country to them both.[128]
Goodeniaceae with ten genera and 220 species Australian, has but two
species in New Zealand--and one of these is a salt-marsh plant found also
in Tasmania and in Chile; and four other large Australian orders--Rhamneae,
Myoporineae, Proteaceae and Santalaceae, have very few representatives in
New Zealand.

We find, then, that the great fact we have to explain and account for is,
the undoubted affinity of the New {491} Zealand flora to that of Australia,
but an affinity almost exclusively confined to the least predominant and
least peculiar portion of that flora, leaving the most predominant, most
characteristic, and most widely distributed portion absolutely
unrepresented. We must however be careful not to exaggerate the amount of
affinity with Australia, apparently implied by the fact that nearly
six-sevenths of the New Zealand genera are also Australian, for, as we have
already stated, a very large number of these are European, Antarctic, South
American or Polynesian genera, whose presence in the two contiguous areas
only indicates a common origin. About one-eighth, only, are absolutely
confined to Australia and New Zealand (thirty-two genera), and even of
these several are better represented in New Zealand than in Australia, and
may therefore have passed from the former to the latter. No less than 174
of the New Zealand genera are temperate South American, many being also
Antarctic or European; while others again are especially tropical or
Polynesian; yet undoubtedly a larger proportion of the Natural Orders and
genera are common to Australia than to any other country, so that we may
say that