Antiquity of the Angiosperms — SUESSENGUTH 
Rustia (from Central America to Brazil), 
and Tresanthera (in Venezuela and in the 
West Indies). None of these genera even so 
much as appears in Australia. The redupli- 
catively valvate species of the Condamineae 
are placed in the genera Portlandia (found 
in the West Indies and in Mexico), Isidorea 
(in Haiti and Cuba), Bikkia (from the Pacific 
islands, New Caledonia, and Malacca), and 
Morrierina (found in New Caledonia). 
Of the Rondeletieae, the simpler species, 
in which there is no contorted vernation of 
the corolla and in which the petals are not 
evolved into showy organs, are placed in the 
genera Rhachicallis (found in the Antilles), 
Bathysa (found in Brazil), and Rondeletia 
(found in the Antilles, Central America, and 
the northern parts of South America ) . 
All of this evidence proves that the Ru- 
biaceae did not originate in Australia, but 
primarily in the tropical regions of Central 
and South America and in the West Indies, 
and only in lesser part in the regions of 
New Caledonia and the Moluccas. 
The most primitive species of the Valeri- 
anaceae appear on the Asiatic mainland: 
Species of Nardostachys, with four stamens 
and the clearly five-parted edge of the calyx, 
are found in the central Himalayas; species 
of Patrinia, with four stamens, extend west- 
ward from Japan through central Asia to 
the Ural mountains and northward into 
Arctic territory. 
Now, in recapitulation, let us list all the 
larger systematic groups of the angiosperms, 
the most primitive types of which are found 
in Australia: Labiatae, Mimosoideae, Papil- 
ionatae, Myrtaceae (sub-family Leptosperm- 
oideae ) , Rutaceae, Santalaceae, Apocynaceae, 
Goodeniaceae, Proteaceae, Restionaceae, Cen- 
trolepidaceae, Loranthaceae, Dilleniaceae, 
Cyperaceae (subfamily Caricoideae ) . This 
summary and all of the evidence leading up 
to it are of great importance for the proper 
evaluation of many of the problems and 
questions in the science of plant geography. 
299 
Most of these groups cannot be considered 
primitive in the general phylogenetic sense — 
as, for example, these nine of the 14 families: 
the Labiatae, Papilionatae, Mimosoideae, 
Restionaceae, Centrolepidaceae, Apocynaceae, 
Myrtaceae, Goodeniaceae, and the subfamily 
Caricoideae of the family Cyperaceae. This 
would mean that the angiosperms which 
have developed in Australia since the Upper 
Cretaceous period cannot be traced back to 
the very earliest groups of angiosperms. These 
ancient groups must have developed in much 
earlier times than the Upper Cretaceous. It 
is not likely that the nine families have 
spread from Australia to other parts of the 
world after Australia’s geographic isolation 
began and that the original primitive species 
have been conserved in Australia ever since 
that time. On the contrary, it is much more 
probable that the primitive ancestral types 
also existed in other parts of the world even 
before the Upper Cretaceous period and that 
they have died out there since that time, 
just as most of the Marsupialia and the 
Monotremata have died out in parts of the 
world outside of Australia. Finally, it should 
be remembered that it is also possible that 
the Australian angiosperms of today might 
have had ancestors originating in other 
continents before the beginning of Austra- 
lia’s geographic isolation. 
It is likely, too, that many of the families 
of the Australian plants have migrated into 
Australia in times later than the Upper 
Cretaceous period, especially those families 
found now in northern, tropical Queensland. 
All of this would mean that parent types 
of most of the derived families of Angio- 
spermae were already in existence before the 
Upper Cretaceous period, and that the de- 
velopment of the main branches of the 
Angiospermae took place in even earlier 
times. Fossil discoveries lead us to suppose 
that a strong and rapid development of 
angiosperms has taken place since the Upper 
Cretaceous period. Investigations of the 
