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BOTANY: PRINCIPLES AND PROBLEMS 



believe that in many cases there has been a fusion of several 

 pistils, and that the many-chambered ovary is thus a compound 

 structure (Fig. 103). The stamens are often the most numerous 

 of the floral parts and are generally free from one another, 

 although in some families they may be partially fused together. 

 The petals are usually fewer than the stamens and rarely exceed 



Fig. 103. — Diagrams of various types of flowers. ^1 and B, Blueberry 

 (Vaccinium). The sepals are united into a gamosepalous calyx, the petals into a 

 gamopetalous corolla, and the ovary is compound, with five cells or chambers. 

 The calyx, corolla and stamens are united with the ovary, or are epigynous. 

 C and D, Tobacco (Nicotiana). Calyx is gamosepalous, corolla gamopetalous 

 and ovary compound, with two chambers. Calyx and corolla are hypogynous 

 but the stamens are attached to the corolla or are epipetalous. 



ten in number. In certain orders they are united to form a con- 

 tinuous or gamopetalous (as opposed to a polypetalous) corolla 

 (Fig. 103). The sepals are generally of the same number as the 

 petals and, like them, may sometimes be fused together into a 

 gamosepalous (as opposed to a polysepalous) calyx (Fig. 102). 

 Not only are the members of one circle sometimes joined together, 



