PARTS OF THE FLOWER 193 



cavity (unilocular), and within it a single anatropous 

 ovule attached to the base of the cavity. 



As a substitute, or for comparison, the head or 

 capitulum of the Dandelion (Taraxacum officinale) should 

 also be dissected : the general features will be similar 

 to the above, the chief points of difference being 

 that 



1 . All the florets are ligulate, and bisexual. 



2. The bracteoles are abortive. 



3. The calyx is developed as a silky pappus. 



For comparison with the above types of flower, which 

 are all Dicotyledonous, examine, as typical of the 

 Monocotyledons, the flowers of the Blue Bell (Scilla 

 nutans), which are borne in simple racemes. Each is 

 composed of 



1. A perianth, consisting of six petaloid segments 

 which are free, or polypetalous, and hypogynous : three 

 composing an outer whorl, overlap the other three 

 which compose an inner whorl. 



2. The androecium, consisting of six stamens, each 

 being opposite one of the segments of the perianth to 

 which it adheres. 



3. The gynoecium, consisting of three carpels, 

 syncarpous and superior : the ovary has three loculi, 

 ovules numerous, placentation axile. 



Compare flowers of Iris, in which the stamens are 

 only three in number, the ovary inferior, and the 

 stigmas petaloid. 



For further details as to the various structure and 

 form of flowers, reference must be made to books on 

 Descriptive Botany. 



