CLASSES. 395 



the Orchis family. The Passion-flower is 

 wrongly put by Linnaeus and others into 

 this Class, as its stamens merely grow out 

 of an elongated receptacle or column sup- 

 porting the Germen. 



21. Monoecia. Stamens and Pistils in se- 

 parate flowers, but both growing on the 

 same plant, or, as the name expresses, 

 dwelling in one house, as the Oak, Hazle, 

 and Fir. 



22. Dioecia. Stamens and Pistils not only 

 in separate flowers, but those flowers situ- 

 ated on two separate plants, as in the 

 Willow, Hop, Yew, &c. 



These two last Classes are natural when 

 the barren flowers have, besides the dif- 

 ference in their essential organs, a different 

 structure from the fertile ones in other re- 

 spects ; but not so when they have the 

 same structure, because then both organs 

 are liable to meet in the same flower. In 

 some plants, as Rkodiola, Engl. Bot. t 508, 

 each flower has always the rudiments of 

 the other organ, though generally ineffi- 

 cient. 



