144 ELEMENTS OP BOTANY. 



number in every case is a multiple of the smallest number 

 found in any set. The stonecrop is symmetrical, since it has 

 five sepals, five petals, ten stamens, and five carpels. Eoses, 

 mallows, and mignonette are familiar examples of flowers 



II 



Fig. 118. — Flower of Stonecrop. 

 I, entire flower (magnified) j II, vertical section (magnified), 



which are unsymmetrical because they have a large indefinite 

 number of stamens ; the Portulaca is unsymmetrical since it 

 has two divisions of the calyx, five or six petals, and seven to 

 twenty stamens. 



Fig. 119.— Irregular Corolla of Laburnum. 

 I, side view; II, front view. 



177. The Receptacle. T-^Th& parts of the flower are borne 

 on an expansion of the peduncle, called the receptacle. 

 Usually, as in the flower of the grape, Fig. 145, this is only 

 a slight enlargement of the peduncle, but in the lotus and the 

 magnolia the receptacle is of great size, particularly after the 



