CHAPTER XV 



THE FLOWER OF THE HIGHER SEED-PLANTS 



175. Organs of the Flower. 



— The parts usually found 

 .p in a flower of the higher 

 |/^ seed-plants are sepals, petals, 

 stamens, and pistils (Fig. 97). 

 The sepals, taken together, 

 constitute the calyx; the 

 petals, taken together, con- 

 stitute the co?-olla. The calyx 

 and corolla are collectively 

 known as the floral envelopes 

 or perianth. 



Many flowers consist of 

 five whorls or circles, tivo of which belong to the perianth. 



Fjg. 97. The Parts of the Flower. 



cal, calyx ; cor, corolla ; st, stamens ; 

 p, pistil. 



Fic. 98. Plower of Stonecrop. 

 I, entire flower (magnified). II, vertical section (magnified). 



two to the stamens, and one to the pistils. The parts of each 

 ivhorl alternate in position vith those of the preceding or 



148 



