TME ARRANGEMENT OF THE FLOWERS 



may arise as the plant grows, the oldest 

 flowers may be .constantly left farther and 

 farther behind on the axis. That is, the 

 flowers which first open are nearest the 

 base of the plant. This type of branch- 

 ing is, as we have already seen (Obs. iii.), 

 indeterminate in type. Plants which have 

 terminal flowers must cease to grow from 

 the ends of the axes, and lateral branches 

 must continue the growth in length. Such 

 type of branching is determinate, or diffuse. 



216. If the lateral flowers of an in- 

 determinate branch are close together, a 

 flower -cluster results; and it opens from 

 below (that is, from the base) upwards. 

 Such a simple inflorescence is a raceme. 



216(1. The lily-of-the-valley (Pig. 184) is a typical 

 example of a raceme. The leaves are reduced to mere 

 bracts. The currant (Fig. 185) is also a, good example. 



217. If the pedicels in a raceme were 

 obsolete, and if the flowers were close to- 

 gether, we should have a typical spike. 



217«r. The common plantain of door-yards (Fig. 

 186) bears its flowers in a spike. In such long spikes 

 there is usually a gradual progression in anthesis (in 

 the opening of the flowers) from below upwards, so that 

 the spike is not in bloom simultaneously throughout 

 its length. The lowest flowers often wither and die, as 



Pig. 186. 



Spike of 

 plantain. 



