PARTS OF THE FLOWER 187 



REPRODUCTIVE ORGANS 



Observations with the Naked Eye on the Mature Flower 



In order to become acquainted with the external 

 characters of the reproductive organs, it will be well to 

 examine and compare a few common types of flower; 

 and since the sexual reproductive process is essentially 

 the same in Dicotyledons and Monocotyledons, the two 

 may be treated simultaneously. 



I. Examine specimens of the common Buttercup 

 (Ranunculus acris) : a number of flowers may be 

 found associated together on a single branching sys- 

 tem, the inflorescence, which has here the character 

 of a cymose panicle. Recognize in each single flower 

 the following series of parts, which are inserted upon 

 the enlarged apex of the axis or floral receptacle : 



1. The calyx, which is the outermost series of floral 

 leaves, and consists of five sepals, separate from one 

 another (or polysepalous), inserted below the other 

 organs (inferior), greenish yellow, and hairy. 



2. The corolla, consisting usually of five yellow 

 petals, separate from one another (polypetalous), and 

 seated below the more central organs (hypogynous) : 

 remove a single petal, and observe the pocket-like 

 gland or nectary on the upper surface, close to the 



