ARRANGEMENT OF FLOWERS ON THE STEM 187 



FIG. 130. Simple Umbel of Cherry. 



198. The Racemes and Related Forms. If the leaves 

 along the stem were to become very much dwarfed and the 



flowers brought closer together, 

 as they frequently are, a kind 

 of flower-cluster like that of the 

 currant (Fig. 129) or the lily- 

 of-t he-valley would result. Such 

 an inflorescence is called a ra- 

 ceme; the main flower-stalk is 

 known as the peduncle ; the little 

 individual flower-stalks are pedi- 

 cels, and the small, more or 

 less scale -like leaves of the 

 peduncle are bracts. 1 

 Frequently the lower pedicels of a cluster on the 

 general plan of the raceme are longer than the upper 

 ones and make a some- 

 what flat-topped cluster, 

 like that of the hawthorn, 

 the sheep laurel, or the 

 trumpet creeper. This 

 is called a corymb. 



In many cases, for ex- 

 ample the parsnip, the 

 Sweet Cicely, the gin- 

 seng, and the cherry, a 

 group of pedicels of 

 nearly equal length 



FIG. 131. Catkins of Willow. 

 A, staminate flowers ; JS, pistillate flowers. 



1 It is hardly necessary to say that the teacher will find it better in every 

 way, if material is abundant, to begin the study of flower-clusters with the 

 examination of typical specimens by the class. 



