The Vegetation of Western Australia. 
XXlll. 
last two — the Genisteae and Podalyrieae — there is a marked southern de- 
velopment. The following list gives the distribution of these two tribes : — 
Genisteae. Podalyrieae. 
South Africa 
19 genera 
Australia .... 
20 
genera 
North Africa and 
8 genera 
North America and 
3 
genera 
Mediterranean 
Siberia 
Australia ... 
7 genera 
Himalayan 
2 
genera 
Warm regions 
2 genera 
Mediterranean 
1 
genus 
Indo-Malayan 
2 genera 
South Africa 
1 
genus 
N. Hemisphere 
(mesothermic) .... 
1 genus 
South America 
1 genus 
It is suggested that both tribes migrated southwards from the northern 
hemisphere, and that the Axistralian Podalyrieae, like the South African 
Genisteae, have formed their own centres of distribution. It will be noticed 
that the Podalyrieae are absent from both New Zealand and South America, 
and that botli have a number of localised endemics in two centres — the Genis- 
teae in the Cape Peninsula of South Africa, and the Podalyrieae in southern 
Australia. 
Finally there is a relationship between the flora of Madagascar and Aus- 
tralia that cannot be overlooked. There is, in the first ])la(5e, the remarkable 
distribution of the Baobab (Adansonia). This genus is restricted to the 
African savannahs, Madagascar, and that portion of Australia wliich lies 
between the Fitzroy and Victoria rivers. In the second place there are those 
genera which are entirely restricted to Madagascar and Australia — -and p^u'- 
ticularly well developed in Western Australia- and Kermidrenia 
(Sterculiaceae), and Diplopeltis (Sapindaceae). No attempt is made to 
explain this rem^irkable distribution. 
3. THE AUSTRALIAN ELEMENT. 
Botanists and zoologists luiN'e rep(‘atedly referred to an Australian Ifli'inent. 
Hooker, speaking of the Australian Flora, states : “ It contains more genera 
and species peculiar to its own areas, and fewer j)lants belonging to other 
parts of the world, than any country of equal extent. About two-fifths of its 
genera, and upwards of seven-eights of its species aix^ entirtdy confined to 
Australia. On the other hand, if, disregarding the pt'culiarities of the flora, 
I (ionipaix' its elements with those of the floras of similarly situated larg(' areas 
of land, or with that of the whole globe, I find that there is so great an agree- 
ment b(>twoen these? that it is impossible to i*(?gard the Australian vegetation 
in any other light than as forming a peculiar but not tu) aberrant or anomalous 
botanical ])rovince of the existing Vegetal)le Kingdom ; that with only two 
small exceptions, the Australian families are also found in other countries ; 
that most of those most widely diffused in Australia are such as are also the most 
wid(fly distributed over the glob(‘ ; and that Australia wants no known family 
of general distribution. Tliat the largo families and gc^nera which, though 
not absolutely restricted to Australia, are then* very abundant in sp(‘cios and 
rarc^ elsewhere, an<l for which 1 shall hence adopt the t(‘rm Australian, stand 
in very close relationship to groups of plants which ar<* widely spn'ad over the 
glob(? {as Kpacridaceae to Fricaceae ; Good(‘uiac(‘a(? to (<ampanula(?eae ; 
Styli(liac(‘ae to LolH'liaceae : ('asuarinaceao to Myrica(H'ao). Turning again 
to other countries vhich are remarkable for tlio peculiarity of tlu?ir vegetation, 
