298 
anthers and an involucre. If we except the 
genus Oreobolus — which is somewhat in a 
special position because of its circum-Pacifk 
distribution and its single, terminal, one- 
flowered false spikelets ( Suessenguth, 1942) 
— we note that genera with alternate or very 
slightly distichous bracteal scales are more 
primitive than are those with distichous 
scales. Among these genera the most prim- 
itive are those which have three style branches 
and an involucre; of these genera three are 
especially worthy of consideration here: 
Lepidosperma, with nine-tenths of its 
species found in Australia, two in New 
Zealand, and two in tropical east Asia 
Tricostularia, with five-sevenths of its 
species found in Australia, one in Bor- 
neo, and one in Ceylon 
Decalepis, with one species found at 
the Cape of Good Hope in South Africa. 
From this evidence we see that — again if we 
except the genus Oreobolus , which is of old- 
Pacific origin and which is difficult to classify 
— most of the oldest types of the Caricoideae 
are to be found in Australia, while the most 
primitive species of the whole family of the 
Cyperaceae are found in the tropics. 
In order to complete the picture we should 
consider some of the families, the origin of 
which cannot be traced to Australia. 
Of the Anacardiaceae the most primitive 
genus is Buchanania, native to tropical Asia, 
especially to the Malaysian territory, and to 
northern Australia. The most primitive spe- 
cies of Buchanania have four to six free car- 
pels, of which one is fertile. 
The Compositae are impossible to trace 
to their origin, or to differentiate into their 
most primitive groups, even if we exclude 
from consideration the tribes which are ob- 
viously derived, like the Liguliflorae and the 
Mutisieae. 
The family Cucurbitaceae is divided into 
the Fevilleae and the Fevillinae. The Fevil- 
leae are the more primitive, having five free 
anthers and loculamenta which are not grown 
PACIFIC SCIENCE, Vol. IV, October, 1950 
together to form a circular ring (except for 
the slightly more developed Gomphogyninae 
and the Zanoninae, which have unilocular 
ovaries ) . The Fevillinae have trilocular ova- 
ries, and, of course, are more highly evolved 
than are the Fevilleae. All of these plants 
are native to tropical America, Brazil, and the 
West Indies. 
Among the Orchidaceae, the more prim- 
itive species (the Diandrae-Apostasiinae) are 
not found in Australia. Species of the genus 
Neuwiedia, which have three fertile stamens, 
appear in Malacca and the Malaysian archi- 
pelago; those of the genus Apostasia, which 
have two fertile stamens, appear in the East 
Indies, the Malaysian archipelago, and trop- 
ical Australia. From this it is evident that 
the oldest types of the whole family belong 
to the tropics and are found today in terri- 
tories lying north of Australia. 
The distribution of the Piperaceae (as, in- 
deed, of many another smaller family), leads 
us to expect a tropical origin for them. 
Of the Rubiaceae, the more primitive sub- 
family is that of the Cinchonoideae, whose 
species have many seeds in each locule of 
the ovary. Among the Cinchonoideae, the 
Cinchoninae are more primitive because of 
their dry fruits. More highly developed 
groups, like the Condamineae and, to some 
extent, the Rondeletieae, have radiate flowers 
which are single or in panicles (but not in 
clusters), apterous seeds, whole or bipartite 
stipules, and the habit of trees or shrubs. The 
Rondeletieae, however, show imbricated or 
contorted vernation of the corolla, and the 
contorted vernation, at least, is a derived 
feature. Among the Condamineae the most 
primitive species are those in which the se- 
pals are of equal size and in which the petals 
are simply valvate and not reduplicatively 
valvate. 
The simply valvate species are placed in 
the genera Condaminea (found in Andean 
South America), Chimarrhis (found in An- 
dean South America and in the Antilles), 
