ARRANGEMENT OF FLOWERS ON THE STEM. 133 
called a head (Fig. 109). Around the base of the head usually 
occurs a circle of bracts known as the involucre, well shown 
in Fig. 110. The same name is given to a set of bracts which 
often surround the bases of the pedicels in an umbel. 
167. The Anthodium. — The plants of one large group, of 
which the dandelion, the daisy, the thistle, and the sunflower 
I 
Fie. 108. —Catkins of Willow. 
I, Staminate flowers ; LI, Pistillate flowers. 
Fie. 107.— 
Spike of 
Plantain. Fic. 109. — Head of Eryngo. 
are well-known members, bear their flowers in close involu- 
crate heads on a common receptacle. The whole cluster 
looks so much like a single flower that it is usually taken for 
one by non-botanical people. This kind of head has received 
the special name of anthodiuwm. In many of the largest and 
