FLOWER-CLUSTERS 



157 



upwards (Fig. 213). The raceme may be terminal to the 

 main branch; or it may be lateral to it, as in Fig. 214. 



Racemes often bear the 

 flowers on one side of 

 the stem, thus form- 

 ing a single row. 

 When a cen- 

 tripetal flower- 

 cluster is long 

 and dense and 

 the flowers are 

 sessile or nearly so, 

 it is called a spike 

 (Fig. 215). Common 

 examples of spikes 

 are plantain, migno- 

 nette, mullein. 



A very shorthand 

 dense spike is a head. 

 Clover (Fig. 216) is 

 a good example. The 

 sunflower and related 

 plants bear many 

 small flowers in a 



very dense and often flat head. Note that in the 

 sunflower (Fig. 189) the outside or exterior flowers 



FIG. 213. RACEME OF CURRANT. 

 Terminal or lateral ? 



FIG. 214. LATERAL RACEMES (in fruit) OF BARBERRY. 



FIG. 215. 

 SPIKE OF 

 PLANTAIN. 



