156 BOTANY. 



arrangement is not like that of umbelliferous plants. The 

 first rays, instead of setting off exactly from the same cen- 

 ter, arise, some a little higher and some a little lower ; the 

 little rays originate with still less regularity ; there is noth- 

 ing like the invariable order you find in umbelliferous 

 plants. In fact, the arrangement of the flowers of the 

 elder is that of a cyme, and not of an umbel." 



But you need not search for all the characters given 

 in the foregoing description in settling the question wheth- 

 er a plant is or is not umbelliferous. If it bears flowers in 

 umbels, and produces inferior fruit, that when ripe sepa- 

 rates into two seed-like bodies, it is an umbelliferous plant. 

 These simple features give precision and distinctness to 

 the order, so that the study of minute characters is only 

 needed in separating this large group into lesser groups 

 with a still greater number of like characters and properties. 

 The number and development of ribs, the presence or 

 absence of vittse, the form of albumen, etc., are used for 

 this purpose. Hence, although a beginner readily sepa- 

 rates the plants of this order from all others, he finds it 

 difficult to tell one genus from another, and, till he ac- 

 quires skill in observation and has some experience in 

 studying its genera and species with the aid of the Flora, 

 he is quite safe in looking upon all of them with suspicion. 



In Order VI, of Chart II, the structure of umbellifer- 

 ous plants is shown in detail. Enlarged sections of the 

 fruit, with all its peculiarities of structure, are represented 

 in such a way as to reveal the parts with great distinctness. 



