124 ELEMENTS OP STRUCTURAL BOTANY. 



You will easily understand,- then, that the production 

 of flowers in such a plant is only limited by the close of 

 the season or by the exhaustion of the plant. Such 



inflorescence is, therefore, called indefinite, or inde- 

 terminate, or axillary. It is sometimes also called 

 centripetal, because if the flowers happen to be in a close 

 cluster, as are the upper ones in Shepherd's Purse, the 

 order of development is from the outside towards the 

 centre. 



187. If you now look at your Buttercup you will be 

 at once struck with the difference of plan exhibited. 

 The main axis or stem has a flower on the end of it, and 

 its further growth is therefore checked. And so, in like 

 manner, from the top downwards, the growth of the 

 branches is checked by the production of flowers at their 

 extremities. The mode of inflorescence here displayed 



is definite, or determinate, or terminal. It is 



also called centrifugal, because the development of the 

 flowers is the reverse of that exhibited in the first mode. 

 The upper, or, in the case of close clusters, the central, 

 flowers open first. 



188. In either mode the flowers are said to be solitary, 

 if (1) single flowers are produced in the axils of the 

 ordinary foliage-leaves (botryose), or (2) if a single flower 

 terminates the stem, as in Tulip (terminal). 



189. Of indeterminate or botryose inflores- 

 cence there are several varieties. In Shepherd's Purse 

 we have an instance of the raceme, which may be described 

 as a cluster in which each flower is supported on a 

 lateral pedicel of its own, usually in the axil of a bract. 

 If the pedicels are absent and he flowers consequently 



