io8 PRACTICAL BOTANY 



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 (Ranuncu- 

 lus acris} : a number of flowers may be found associated 

 together on a single branching system, 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 haiiy. 



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 base. 



3. The andrcecium, consisting of an indefinite number of 

 stamens, which are separate from one another (polyandrous), 

 and are seated below the central series of organs (hypogynous) : 

 each stamen is a club-shaped body, and two parts of it are to 

 be recognized 



a. A thin stalk, the filament. 



b. A two-lobed head, the anther. 



In a flower fully opened, note with a lens the dehiscence of 



