176 Plant Life and Evolution 



a " syncarpous," or compound pistil. The lower 

 part of the pistil, or ovary, usually clearly shows the 

 number of carpels of which it is composed either by 

 being divided into chambers or having a correspond- 

 ing number of placentae, from which the ovules 

 grow. The upper part of the floral axis is frequently 

 extended into a tube at the bottom of which the 

 ovary lies, and in very many flowers both Chori- 

 petalse and Sympetalse, the lower portion of the tube 

 may be completely fused with the ovary, and the 

 latter is then said to be inferior, the other parts of 

 the flower being " epigynous." Such epigynous 

 flowers are considered to be more specialized than 

 those in which the ovary is free. The iris, nar- 

 cissus, canna, and the orchids are typical examples 

 of epigynous monocotyledons, while the fuchsia 

 and the Compositae are illustrations of epigyny in 

 the dicotyledons. 



Sympetaly, or the union of the petals, is a 

 common phenomenon in both the monocotyledons 

 and dicotyledons. It reaches its extreme in such 

 flowers as the morning-glories or the fox- 

 glove, where the limits of fhe individual segments 

 or petals are almost obliterated. Finally in the 

 orchids there is an almost complete coalescence of 

 the carpels and stamens, the latter being reduced 

 in most cases to a single one. 



The Most Specialized Flowers are Zygomorphic. 

 In the more primitive flower the parts are usually 

 arranged radially, but in many flowers the sym- 



