144 ELEMENTS OF 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. Roses, 
mallows, and mignonette are familiar examples of flowers 
FIG. 118.— Flower of Stonecrop. 
I, entire flower (magnified); I, 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. 
Fic. 119. — Irregular Corolla of Laburnum. 
I, side view ; LI, front view. 
177. The Receptacle. — The 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 
