FLOWERS AND THEIR USES 



263 



a tube. In the flowers of the sunflower, the dandelion, and 

 others of the composite family, the five stamens are united 

 by their anthers, the filaments being separate. The stamens 

 of some flowers are joined to the petals, or to the sepals, or 

 to both. The Roman hyacinth has a stamen opposite, 

 and partly united with, ^ -^-r-^ 



and each 



X 



I 



each sepal 

 petal. 



A pistil may be com- 

 posed of a single macro- 

 spore leaf, as in the bean 

 which has but one pistil, 

 or in the strawberry 

 which has many. But 

 in many flowers the 

 pistil is a compound 

 structure formed by the 

 union of two or more 

 macrospore leaves. The 

 pistil of the sunflower or 

 of the dandelion is com- 

 posed of two macrospore 

 leaves ; that of the lily 

 or the hyacinth of three; 

 and that of the apple 



usually of jive. These compound pistils are less primitive 

 than the simple pistil of the bean or of the com. Still 

 another form of union of parts is seen in the pistillate 

 flower of the cucumber. There the sepals and petals are 

 grown together with the wall of the ovary. As a result, 

 instead of being attached to the flower-bearing branch 

 below the ovary, as in the lily flower for example, the 

 sepals and petals seem to grow out of the top of the ovary. 

 In the sunflower, sepals, petals, and stamens are united 

 in the same way with the ovary wall. In this respect, 



Fig. 154. — Cross section through the 

 ovary of a Hly, showing how it is formed 

 by the union of three macrospore leaves. 

 Six ovules appear in the section — two in 

 each of the three cavities of the ovary. 



