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Show 4GO ISLAND LIFK (PART H. But this by no means exhausts the differences between ~ew Zealand and Australia. No less than seven important Australian Natural Orders-Dilleniacore, Buettneriacere, . Polygalere, .Tre-mandrere, Casuarm. ere, H remo d oracere, a nd XvJ nde• re are entirely wanting in New Zealand and sever~l ?thers w h1eh are exces~ively abundant and highly charactenstic of the former co~nti y are very poorly represented in the latter. Thus, Legummosm are extremely abundant in Australia, where there are over 1,000 Species belonO'ina to about 100 genera, many of them altogether ' 0 b 1. )eculiar to the country; yet in New Zealand t ns great order Is most scantily represented, there being only five ~ener~ and thirteen species ; and only two of these genera, ~wa~nsoma and Glianthus, are Australian, and as the latter consists of but two species it may ns well have passed from New Zealand . to Australia as the other way, or more probably from some tlurd country to them both. Goodeniacere wit~ t;venty genera and 230 species Australian, has but two species In New Zealandand one of these is a salt-marsh plant found also in Tasmania and in Chile ; and four other large Australian orders- Rhamnem Myoporinere, Proteacere and Santalacere, 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 Zealand flor[l. to that of Australia, but an affinity almost exclusively confined to the least predominant and least peculiar portion of that fl ora, 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 sixsevenths 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 n 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 17 4 of the New Zealand genera are CHAr. XXII.] 'fHE FLORA OF NEW ZEALAND. 4Gl t emperate South American, many being also Autarctic 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 the basis of the flora is Australian with a large intermixture of uorthorn and southern temperate forms and others which have remote world-wide affinities. .l· General jeat~tns of the Australian, PlO?·a and its probable Origin.-Before proceeding to point out how the peculiarities of the New Zealand flora may be best accounted for, it is necessary . to consider briefly what are the main peculiarities of Australian vegetation, from which so important a part of that of New Zealand has evidently been derived. The actual Australian flora consists of two great divisionsa temperate and a tropical, tho temperate being again divisible into an eastern and a western portion. Everything that i$ characteristic of the Australian flora belongs to the temperate division (though these often overspread the whole continent), in which are found almost all the rema~kable Australian types of vegetation and the numerous genera peculiar to this part of the world. Contrary to what occurs in most other countries, the tropical is far less rich in species and genera than the temperate region, and what is still more remarkable it contains comparatively few peculiar species, and very few peculiar genera. Although the area of tropical Australia is about equal to that of the temperate portions, and it has now been pretty well explored botanically, it has less than half as many species.q 1 Sir Joseph Hooker informs me that the number of tropical Australian plants discovered within the last twenty years is very great, and that the statement as above made may have to be modified. Looking, however, at the enormous disproportion of the figures given in the "Introductory Essay" in 1859 (2,200 tropical to 5,800 temperate species) it seems hardly possible that a great difference should not still exist, at all events aR regards species. Sir Joseph Hooker also doubts the generally greater richness of iropical over temperate floras which I have taken as almost an axiom. He says: '' Taking similar areas to Australia in the W estem World, e.g., tropical Africa N. of 20° as against temperate Africa an(l Europe up to 47°-I suspect that the latter would present more genera ancl |
