PARTS OF THE FLOWER 189 



regular cymose inflorescence (dichasium). The flower 

 is composed of 



1. Calyx, sepals five, polysepalous, inferior. 



2. Corolla, petals five, deeply notched, polypetalous, 

 hypogynous. 



3. Androecium, stamens ten, polyandrous, or very 

 slightly united at the base, hypogynous. 



4. Gyncecium, carpels three, united or syncarpous, 

 superior : styles and stigmas three. Ovary unilocular, 

 ovules numerous, inserted on the prolongation of the 

 axis (central placentation). 



This affords an example of cohesion of the carpels. 

 Compare the Rose Campion (Lychnis dioica), which 

 belongs to the same natural order, and shows the same 

 general characters ; but the plants are more or less 

 distinctly unisexual, flowers with perfect stamens 

 being borne on some plants, while on others flowers 

 will be found with only the female organs matured : the 

 species is thus dioecious. 



Note the calyx with united sepals, gamosepalous : in 

 the male flowers there are ten stamens slightly united 

 at the base, and centrally a rudimentary gynoecium ; 

 in the female flowers, the gyncecium consists of five car- 

 pels, syncarpous and superior, while around its base may 

 be seen ten rudimentary stamens : thus this plant 

 illustrates cohesion of the sepals and of the carpels, and 

 a partial suppression of the stamens, or of the 

 carpels. 



IV. Examine flowers of the Bird-Cherry (Prunus 

 Padus) : they are arranged in racemose manner. Note 

 that each flower consists of 



1. A calyx of five sepals, inserted upon the so- 



