162 THE BEHAVIOUR OF PLANTS 
most prominent part is like a strap. The other flowers 
are more numerous. ‘They are shaped somewhat like a 
tube, and’ have been called tubular flowers. Because 
they form a large disk in the centre of the flower head 
they are also called disk flowers. Each one of the little 
3 ray and disk flowers 
is called a floret. 
The behaviour of the 
florets in flowering. 
If you will read from 
several sunflower 
heads, or read from 
one day by day, you 
will learn an interest- 
ing story. You can 
cut off a head and 
put the stem in a 

FIG. 199. Sunflower head. 
vessel of water in the 
room where you can see it from day to day. It will 
behave very well for several days. You do not need 
_ to pick the flowers to pieces. Just look now and then 
at the disk florets. 
First, in those next the ray flowers, the pollen is 
pushed out from the pollen cases and lifted above the 
corolla tube, so that the pollen grains can be scattered. 
It is the growing pistil in each floret which pushes the 
pollen out. Then in a few more rings next these and 

— 
