262 ELEMENTS OF BOTANY 
by the succession of families in the Flora which accom- 
panies this book, the Willow family being perhaps the 
oldest (of the familiar dicotyledons) and the Composite 
family the youngest. 
The beginner in systematic botany must guard himself 
from the natural tendency to feel that the simpler types of 
flowers, like those of the Buttercup family and the Stone- 
crop family, with their organs distinct and hypogynous, 
are more perfectly organized than sympetalous flowers. 
This is not the case. It is in such bilatersi flowers as 
those of Figs. 129 and 132, and in such consolidated clus- 
ters as those of the yarrow, shown in Fig. 8 of the Appen- 
dix, that we are to recognize the highest types reached in 
floral structures. 
