116 



FLOWER -BEANCHES 



the flowers are borne on short stems and open from below 

 (that is, from the older part of the shoot) upwards. The 



raceme may be terminal to the 

 main branch, as in Fig. 172, or 

 it may be lateral to it, as in 

 Fig. 173. Racemes often bear 

 the flowers on one 

 side of the stem , or 

 in a single row. 



238. When a 

 corymbose flower- 

 cluster is long and dense 

 and the flowers are sessile 

 or nearly so, it is called 

 a spike (Figs. 174, 175). 

 Common examples of spikes 

 are plantain, mignonette, 

 mullein. 



239. A very short and 

 dense spike is a head. Clover 

 (Fig. 176) is a good exam- 

 ple. The sunflower and re- 

 lated plants bear many small 

 flowers in a very dense head. This special kind of head 

 of the sunflower, thistle, and aster tribes has been called 

 an anthodium, but 

 this word is little 

 used. Note that 

 in the sunflower 

 (Fig. 177) the out- 

 side o r exterior 

 flowers open first. 



Another Special 173> Lateral racemes (in fruit) of barberry. 



form of spike is the catkin, which usually has scaly bracts 

 and the whole cluster is deciduous after flowering or fruit- 



172. Terminal racemes of dicentra. 



