CHAP, xxi COALESCENCE AND ADNATION 93 



CHAPTER XXI 



COALESCENCE AND ADNATION 



I. Take a flower of Convolvulus or Morning Glory 

 (Ipomcea) and notice : 



1. That the corolla is made up of one piece. 



2. That there are five points or stripes to indicate that five 



petals are joined together at their edges. 



3. Make a sketch of this corolla. 



4. Such a corolla is said to be sympetalous, or having the 



petals united. 1 



II. When parts of the same circle are joined together, as 

 in the case of the petals of the Morning Glory, it is called 

 coalescence. Parts of any of the four circles may be joined. 



Take the Pea Flower again, and notice : 



1. The calyx, it is synsepalous. Notice the lobes indicat- 



ing the sepals composing it. 



2. Removing the corolla, notice that nine of the stamens 



are united into one piece by their filaments, the 

 tenth remaining free. 



3. Such stamens are called diadelphous (in two brother- 



hoods) if in one piece, as in some flowers of this 

 family, monadelphous, etc. 



1 When the petals are separate (or " distinct "), the corolla is said to be 

 choripetalous. 



