Origin and Development of the Composite. 211 
in phylesis; it is also proved by the fact that the other characters 
which are analysed by Beauverd do not follow the same sequence 
as the homogamy or heterogamy of the capitulum. 
The data available for the determination of the times of origin 
of the two main lines are confined to the probable origin of the 
Senecioneae in the Upper Cretaceous, the known development of 
the Cynareae in the Upper Miocene and the present geographical 
distribution of all the groups concerned. From these data, however, 
the date of the first development of the Eu-gnaphalieae can be 
placed soon after the origin of Senecio , probably early Eocene ; and 
the date of the origin of the Inulinae must have been later than 
that but some time before the Upper Miocene. Taking all the facts 
into consideration the date indicated is the middle Oligocene. Such 
a date would account for the absence of the Cynareae from the lower 
Oligocene and would also give a sufficient interval for the develop¬ 
ment of the Arctium type of the Cynareae in the Upper Miocene 
(see below under Cynareae). At the same time it would account 
for the similarity in the present distribution of the Inulinae and 
Cichorieae, as well as for the greater area occupied by the latter, 
which is the older group. 
Cynarece. Two possible sources, the Plucheinae and Buphthal- 
minae, have been suggested for the Cynareae and a diphyletic origin 
of the tribe has been indicated as a possibility. As diphylesis is 
supported only by the evidence from the pappus it will be neglected 
until a more detailed examination has been made of the evolution 
in the tribe. The rest of the characters, including the geographical 
distribution and the secretory apparatus, support a monophyletic 
origin of the tribe from the Inuleae via the Buphthalminae, Gym- 
narrhena, C'entaurea and the Centaureinae. So close is the affinity 
that a microscopic investigation is necessary to distinguish some 
plants of Gymnarrhena micrantha (Inuleae, Buphthalminae) from 
Centaurea Jurfuracea (Cynareae, Centaureinae) and these two species 
grow in the same region. 
The development of the Carduinae from the Centaureinae with 
the Carduus-Cousinia group as the basal plexus is clear, as is also 
the development of the Carlininae and Echinopsidinae from the 
Carduinae. The evolution of these two sub-tribes along different 
lines from the same source is well shown in the secretory apparatus, 
the Carduus plexus gives the Cirsium line in the Carduiinae and the 
parallel Carlina line in the Carlininae; the same plexus gives the 
Echinopsidinae line and the parallel Xeranthemum line in the 
