108 THE CALYX AND COROLLA. [LESION 16. 



one side, and spread out flat. To prove that this is the case, we have 

 only to compare such a corolla (that of Coreopsis, Fig. 220, c, or 

 one from the Succory, for instance) with that of the Cardinal-flower, 

 or of any other Lobelia, which is equally split down along one side ; 

 and this again with the less irregular corolla of the Woodbine, par- 

 tially split down on one side. 



LESSON XVI. 



ESTIVATION, OR THE ARRANGEMENT OF THE CALYX AND CO- 

 ROLLA IN THE BUD. 



279. ^ESTIVATION or Prcefloration relates to the way in which 

 the leaves of the flower, or the lobes of the calyx or corolla, are 

 placed with respect to each other in the bud. This is of some 

 importance in distinguishing different families or tribes of plants, 

 being generally very uniform in each. The aestivation is best seen 



FIG. 221. Compound flowers, i. e. heads of flowers, of Succory. 



