Flowers and their Parts 



117 



come more and more like the foliage leaves further down on 

 the stem. Bracts are modified leaves. Are all flowers sub- 

 tended by bracts ? 



Relation of Flower Parts. — Just as bracts merge into 

 leaves, so the sepals may become quite leaf-like, and there are 

 green roses and dahlias in which the petals have taken on the 

 appearance of leaves. Usually stamens and 

 pistils look very unlike leaves, but here the 

 garden flowers come in as teachers. 



A canna flower is interesting. Above 

 the ovary are three small sepals ; then three 

 narrow-pointed petals. The showy part 

 comes next, and on one of them an anther 

 locule is formed; the other locule is re- 

 placed by a petal-like part. It must be a 

 stamen. It is the only one which bears 

 an anther, but from the position of the 

 others we call them sterile stamens, or 

 staminodia. 



Water-lilies and garden flowers which double show all 

 gradations of stamens that have become transformed into 

 petals. 



The pistil at the very centre of the flower has been so 

 protected and has its one special work to perform, the bearing 



Fig 



0. — Spathe of 

 Richardia Africaiia 

 surrounding spadix. 



Fig. 131. — Stages of transition between the petals and stamens oi Rosa centifolia. 

 (From Thomd and Bennett's " Structural and Physiological Botany.") 



of seeds, that it is seldom altered so as to make evident its 

 kinship to the leaves. The carpels of Sterculia appear like 

 five leaves with petioles. Before they are ripe they spread 

 open, and the seeds ripen along their edges. In the " Christ- 

 mas rose," leaves and leaflets take the place of ovaries and 

 ovules. The centre of the flower is a mass of crumpled leaves. 



