188 PRACTICAL BOTANY 



3. The androecium, consisting of an indefinite num- 

 ber 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. 



I. A two-lobed head, the anther. 



In a flower fully opened, note with a lens the dehi- 

 scence of the anthers by two longitudinal slits, through 

 which the powdery yellow pollen may escape. 



4. The gyncecium at the centre of the flower, 

 consisting of an indefinite number of carpels, which 

 are separate from one another (apocarpous), and are 

 seated above the other floral organs on the conical 

 receptacle (superior). Each carpel consists of a lower 

 laterally compressed portion, the ovary, and at the 

 apex of a short curved process (the style) is a rough 

 yellow surface, the stigma. Open one of the carpels 

 carefully, and observe an internal cavity, containing a 

 single round body, the ovule. 



II. Compare the flower of CaltTia palustris, the 

 Marsh Marigold. Here the general arrangement of 

 parts will be found to be the same : but note the 

 following points of difference that the calyx is here 

 petaloid, consisting of five or more sepals, the corolla 

 is absent, and the carpels are fewer (five to ten), but of 

 larger size. Slit open one of the carpels along the dorsal 

 side, turn back the flaps, and observe the numerous 

 ovules, attached to the ventral side of the carpel, and 

 arranged in two irregular longitudinal rows. 



III. For comparison of the above, examine the 

 greater Stitchwort (Stellaria holostea), and note the 



