FLOWERS 297 



of the potato. The eyes are buds which, when placed in 

 soil, produce new potato plants. 



Not only the leaf and the stem, but also the root, may 

 become thickened, and be used for the storing of food. 

 The radish, turnip, parsnip, and carrot are thickened 

 tap roots; the sweet potato is a "fleshy" branching root. 



318. Flowers We are now to study the flower, the 

 wonderful organ through which the higher plants repro- 

 duce themselves from generation to generation. 



The complete flower has four sets of parts (Fig. 244), 

 and each of these is usually arranged in a whorl (cf. 309) 

 around the flower stalk. The car pe is 



outer set is called the calyx, or 

 "cup," of the flower; its sepa- 

 rate parts are called sepals. The 

 next set of parts is called the 

 corolla ; each part of the corolla 

 is a petal. The third set con- 

 sists of the stamens, the organs 



FIG. 244. Parts of a Flower. 



that produce the pollen. The 



innermost set is the carpels; these produce the seeds. 

 The top of the flower stalk, on which the parts of the 

 flower are arranged, is called the receptacle. 



The corolla is usually the attractive, colored part of the flower. The 

 calyx is often highly colored also, but commonly it is green, like true 

 leaves. The flower is really composed of modified leaves (cf. 311). 

 The calyx and corolla are the most leaf-like parts, and enclose the 

 stamens and carpels, the real organs of reproduction. Often the calyx 

 or the corolla is in one piece, as a result of the joining together of the 

 sepals or the petals. We see this in the morning-glory and the bluebell. 



