292 
PACIFIC SCIENCE, Vol. IV, October, 1950 
According to A. Engler (1882), 425 of 
the 1,393 genera of the Australian flora — 
that is, 30.5 per cent — are endemic. This is 
a statement of great importance, for from it 
we learn that the time interval between the 
Upper Cretaceous period and the present 
time has been sufficient for the creation of 
a great number of new genera — almost a 
third of the genera found in Australia — or 
for the conservation in Australia of a part of 
them while in other continents they have be- 
come extinct. It has already been stated that 
the same suppositions are valid for 90 per 
cent of all the Australian species. In short, 
the period from Upper Cretaceous time until 
the present has been long enough to create, 
or, exclusively, to conserve, 30.5 per cent of 
the genera and at least 90 per cent of the 
species of the Australian flora. On the other 
hand, it has not been long enough a time to 
permit the creation, or the exclusive conser- 
vation, of very many of the families of the 
Australian flora, particularly of the larger 
families. 
It is interesting, for the sake of compari- 
sons not unimportant to the arrival at a con- 
clusion, to see how the species of the larger 
groups are distributed in other parts of the 
world. According to Hegi’s Flora (1906- 
1931 ), the larger groups of plants are repre- 
sented in central Europe — Germany, Austria, 
and Switzerland — -by the numbers presented 
TABLE 3 
Representation of Endemic Species among 
the Larger Plant Groups of Central 
Europe and Australia 
PLANT GROUP 
NUMBER 
OF SPECIES* 
PERCENT- 
AGE OF 
“higher 
flora” 
COM- 
PARABLE 
FIGURES 
FOR 
AUSTRALIA 
Pteridophytae 
74 
2.3 
2.8 
Gymnospermae 
11 
0.3 
0.5 
Monochlamydeae 
355 
11.2 
12.8 
Dialypetalae 
1,043 
32.9 
41.2 
Sympetalae 
1,042 
32.8 
25.2 
Monocotyledones 
648 
20.4 
17.6 
"According to Hegi (1906-1931). 
in column 1 of Table 3. These figures are 
converted, in column 2, into percentage val- 
ues which can be compared with the figures 
for the same plant groups in Australia 
(column 3). 
In several of these groups- — the Pterido- 
phytae, the Gymnospermae, and the Mono- 
chlamydeae — the percentage values for Aus- 
tralia do not differ much from those of central 
Europe. In Australia the Monocotyledones 
and the Sympetalae appear somewhat less 
frequently than they do in Europe; while the 
Dialypetales are found somewhat more fre- 
quently in Australia than in central Europe. 
In R. Mansfeld’s catalogue of ferns and 
flowering plants (1940), the figures given 
for that part of central Europe included in 
Germany, Austria, Bohemia, and Moravia are 
presented in Table 4. 
In northern Europe the Monocotyledones 
are even more plentiful. In England they 
form 25.3 per cent of the flora (Druce, 
1932); in Iceland and the Faroes, 30.8 per 
cent (Ostenfeld, 1934); in Greenland, 31.2 
per cent (Ostenfeld, 1926); in Novaya 
Zemlya, 33.3 per cent (Ekstam, 1897); and 
in Spitzbergen, 31.2 per cent (Nathorst, 
1883). In Portugal the Monocotyledones 
form 20.3 per cent of the flora (Palhinha, 
1939); in Italy, 18.6 per cent (Buscalione 
and Muscatello, 1911-1913); in the Bal- 
kans, 16.3 per cent (calculated from Hayek 
and Markgraf, 1927-1933); and in the ter- 
ritory of the Aegaean islands, 17.5 per cent 
(calculated from Rechinger, 1943). It be- 
comes apparent, then, that the number of 
species of Monocotyledones is greater in 
northern Europe than it is in southern 
Europe. 
With the Sympetalae quite the opposite 
representation is found: the northern coun- 
tries have fewer of these, the southern coun- 
tries have more: Spitzbergen has 13.5 per 
cent; Novaya Zemlya, 16.5 per cent; Green- 
land, 21.1 per cent; the Faroes, 25.5 per 
cent; England, 25.4 per cent; Germany, 29.5 
