COMPOSITE FLOWERS 25 
and many other plants belong, that have their many small flowers 
grouped in a compact head as shown at A in Figure 23. This 
group of plants is called Composites, and includes some of our 
useful plants as well as some of the most troublesome weeds. 
Both calyx and corolla are somewhat peculiar. In some cases, 
as in the Sunflower, the flowers occupying the center of the head 
have tube-like corollas and are called tubular flowers, while those 
around the margin have strap-shaped and much more showy 
corollas, and are called ligulate flowers. See A, B, and C of 
Figure 23. In some of the Composites, as in the Dandelion, all 
of the flowers of the head are ligulate, while in some, like the 
Thistle, all the flowers are tubular. The calyx is often composed 
