204 STUDY OF COMMON PLANTS. 



c. The uppermost leaves. Those subtending a group 

 of inflorescences constitute an involucre, those 

 subtending each separate inflorescence an in- 

 volucel. Do the leaves of involucre and involu- 

 cel differ in any important particular from the 

 lower leaves ? 



4. The character of the inflorescence, and the grouping 

 of several inflorescences to form a compound umbel. 



Flower. 



I. Examine different flowers until you are satisfied as to 

 what parts are present. Note the essential facts of form, 

 number, position, etc. 



II. Write a description, and indicate all the points in 

 which this differs from a " typical flower." 



NOTE. In this family the inflorescence and flowers are particularly 

 characteristic ; it is important, therefore, that their distinctive features 

 should be impressed on the mind before proceeding farther. 



Fruit. 



Fully mature specimens are indispensable in studying 

 the fruit of any member of this family ; accordingly, 

 instead of waiting for the Erigeriia to ripen, it will be con- 

 venient to take commercial specimens of fennel, coriander, 

 and dill, which will serve as good representatives of the 

 fruits of umbelliferous plants. Moreover, by studying 

 several kinds, instead of one, we shall gain a clearer im- 

 pression of their really characteristic features. 



I. Observe carefully the external features of the three 

 fruits. That of the coriander is globular, fennel is more 

 nearly cylindrical, while dill is much flattened. In spite, 

 however, of these marked differences, there are a number 

 of characters common to all three. Note 



