93 PRACTICAL BOTANY. 



175. The order of flowermg in indefinite inflorescence 

 is centripetal, or ascending, which is the same thing. In 

 its several forms we notice that either the lowest or the 

 outermost flowers are the oldest. If we suppose the main 

 axis to be contracted, as is really the case in the umbel, 

 the lower, lateral axes will be the outer, while the upper 

 will be the inner. The lower lateral axes, regarded as 

 the outer, will represent the periphery, and the upper, re- 

 garded as the inner, the centre of a circle. The youngest 

 flowers are in the centre. 



BB. DEFINITE DTPLORESCENCB. 



176. Definite or determinate infiorescence is that sort 

 of inflorescence in which the flowers grow from terminal 

 buds. If it be represented by three flowers (which, by- 

 the-by, resemble a simple umbel), the middle and largest, 

 or oldest flower arrests the growth of the axis ; and 

 further growth can not take place but by the development 

 of other axes from axillary buds. These secondary axes, 

 if they are leafy shoots, as in our inflorescence of three 

 flowers, will sooner or later be terminated each by a flower 

 in their turn (PI. II., 23) ; and when other (tertiary) axes 

 spring from axillary buds of these secondary axes, they 

 will also be checked by a terminal blossom. (PI. II., 26.) 



Definite inflorescence occurs chiefly in opposite-leaved 

 plants ; but sometimes in alternate-leaved, as the Kose 

 and Potentilla. This sort of inflorescence assumes forms, 

 which closely resemble those of the definite. Both sorts 

 have often been confounded, and not unfrequently they 

 are combined. 



177. There are three principal forms of definite in- 

 florescence — namely, the cyme, the fascicle, and the glo- 

 merule. 



The cyme is a flat-topped, rounded, or expanded, defi- 



