150 THE SECOND BOOK OF BOTANY. 



In the matter of adhesion, you always found the 

 calyx-tube adherent to the ovary (Fig. 308), forming 

 the peculiar kind of achenium, known as a cypcela, 

 and on further inspection you would find one erect 

 exalbuminous seed (Fig. 307) ; and, if you were to 

 examine the entire nine thousand species, you would 

 find them all bearing the same characters. 



But you need not discover all these characters 

 before you decide that a given plant belongs to the 

 composite order. If you find syngeneseous stamens 

 in the florets of a dense flower-head, it settles the 

 question. The coexistence of the two characters 

 makes sure the inference that the plant has all the 

 above-named characters, and also that it is more or 

 less bitter. 



Well, you have now the means of easily recog- 

 nizing the members of this great family. They differ 

 from all other plants, not in their inflorescence, for 

 many other plants blossom in a head ; not in having 

 syngeneseous anthers, for in many other plants the 

 anthers are coherent ; but they differ from all other 

 plants in possessing both these characters. This 

 circumstance is, therefore, said to characterize the 

 compositse. Observe the distinction between that 

 which characterizes an order and the characters of 

 that order. The coexistence of the two characters 

 syngeneseous anthers and a flower-head is sufficient 

 to identify any plant of the order compositse, or, 

 what is the same thing, to characterize it ; but all the 

 other characters that invariably accompany these are 

 the characters of the order. 



Though all composite plants are alike in certain 

 particulars, called their ordinal characters, they differ 



