Flowers and Flower Clusters 



23s 



Fig. 13S. Catkins of staminate flowers of red oak {Quercus rubra). 



been invented to describe them. In many plants the flowers 

 occur singly at the ends of stems or lateral branches, as in the 

 tulip and in some varieties of roses. The stem which bears a 

 flower or flower cluster is called a peduncle. In flower clusters 

 the small branches which bear the individual flowers are called 

 pedicels. 



In the spike of the common plantain, cat- tail, and timothy, the 

 flowers are arranged along the sides of the upper part of the pe- 

 duncle. The catkin of the willow, poplar, alder, and oak differs 

 only in that it droops. The raceme of the garden currant differs 

 from the spike in the fact that the^ flowers are borne on long pedi- 

 cels at some distance from the peduncle. In the umhel of the 

 onion, milkweed, carrot, and cherry, the pedicels all arise at the 

 top of the peduncle and are of about the same length, so that the 

 cluster is more or less flat topped. The corymb of the hawthorn 



