CHAPTER XVI 

 FLOWER STRUCTURE 



THE floral organs are developed from leaves, 

 which, by various processes of modification, have been 

 fitted to perform the functions of producing seeds. 

 In many instances the relationship between the floral 

 part and the leaf, as regards both characters and 

 structural peculiarities, is clearly evident. The sepals, 

 or parts of the calyx, usually bear a close resemblance 

 to leaves, in color and form. In other floral organs 

 the modifications so obscure this relationship that 

 the true nature of the organ in question can only be 

 ascertained by considering its ontogeny, or the changes 

 occurring during the period of its development. The 

 stamens bear little resemblance to foliage leaves; 

 and it is only by a study of the changes which occur 

 during their development that the structural relation- 

 ship has been established. Each organ of the flower 

 possesses structural characters peculiar to itself, and 

 more or less common to corresponding parts in other 

 flowers. However, the deviations from typical char- 

 acters are so frequent in the floral organs, that it is 

 impossible to give descriptions which will apply in 

 all instances. The structures present in a typical 

 complete flower, beginning with those of the outer- 

 most circle, are as follows: 



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