372 FLORA HTSTORTCA. 



the most interesting classes. It contains a natu- 

 ral order of plants perfectly distinct from any 

 others which the vegetable creation presents to 

 our view ; consequently, their arrangement in the 

 artificial system of the illustrious Swede is pecu- 

 liar to themselves. This class could not be de- 

 fined by the number of stamens and pistils, since 

 all the numerous genera contain the same, which 

 made it necessary to find other characters in the 

 flowers so as to form the bases of subdivision. 

 For this purpose Linnaeus adopted the polygamy, 

 or intermixture of the sexes in the florets. 



The characters of the class Syngenesia being 

 of a decidedly different nature from other flowers 

 may be easily known. It consists, first, in the 

 congeneration of the anthers, which is uniform 

 through all its numerous genera ; and, secondly, 

 that more than one floret is always contained in 

 each calyx ; this is sufficient to determine any 

 plant to belong to the 19th class, Syngenesia. 



The Sun-flower, more particularly the single 

 one, presents you with a clear idea of the class 

 and order to which it belongs, since you see the 

 parts on a large scale. The common receptacle 

 supporting all the numerous florets on its surface, 

 each of these florets are, in fact, a separate mo- 

 nopetalous flower, having within itself the parts 

 necessary for the formation of seed. 



