SPERMATOPHYTES 



139 



angiosperm carpel are the ovary and the stigmatic surface, 

 and that a style is generally present because it insures a more 

 favorable position to the stigmatic surface for receiving the 

 pollen. 



A flower may have a single carpel, or it may have several. 

 In the latter case, the carpels are arranged in one of two 

 ways : (1) they may be distinct from one another (Fig. 110, 

 A), or (2) they may be organized together in a single body 

 (Fig. 110, B and C). It is convenient to have a term that 

 may be applied to either situation, and that term is pistil. 



FIG. 111. Cross-sections of ovaries of compound pistils : A, three carpels forming a 

 "one-celled" ovary; B, three carpels forming a "three-celled" ovary.. After 

 SCHIMPEB. 



A pistil is a single structure, with its ovary, style, and stig- 

 matic surface, but it may consist of a single carpel or of two 

 or more carpels organized together. These two conditions 

 of the pistil are distinguished as simple pistils and compound 

 pistils (often called syncarpous pistils, which means pistils 

 with " carpels joined together "). The term pistil, there- 

 fore, is one of convenience rather than of exactness, for 

 sometimes it is identical with carpel and sometimes it in- 

 cludes two or more carpels. It is like the word " house, " 

 which may include one room or two or more rooms. It fol- 

 lows that there are three possible carpel conditions in a flower : 

 (1) a solitary carpel and therefore a single pistil ; (2) two 

 or more carpels forming as many pistils; and (3) two or 

 more carpels forming a single pistil. 



