220 THE STEUCTURE OF FLOWERS. 



CHAPTER XXiy. 



PARTIAL DICLIXISM. 



Gynodicecism and Gynomon(i:cism. * — In accounting for the 

 origin of certain floral structures, it must be borne in mind 

 that the habits and constitutions of plants are so infinitely 

 various, that the interpretation given for that of a structure 

 in one case may fail to be satisfactory when tested by 

 another ; and an argument apparently sound for the expla- 

 nation of a special phenomenon in a particular plant «r 

 plants may not at all apply to that of others. Thus, while 

 the Hazel may mature its stamens before the pistils on a 

 slight rise of temperature in early spring, there are many 

 herbs, if they happen to blossom in spring earlier than is 

 their custom, in summer, or what may be their optimum 

 period, may have the staminal whorl more or less deranged, 

 as such plants require a relatively higher temperature to 

 develop them perfectly.f This is particularly characteristic 

 of gynodioecious plants. Thus, e.g., most of the distinctly 

 protandrous species of the Alslnece are in this condition, and 



* Gynodiajcinn signifies that the same species may have both female 

 and hermaphrodite plants. 



Gynomoncecism signifies that the same plant may bear both female 

 and hermaphrodite flowers. 



t This will be discussed more fully in the next chapter. 



