THE PARTS OF A FLOWER. 237 



the filaments are united at the bottom, but 

 separate at the top ; as in the Geranium. 



17. Diadelphia, or two brotherhoods. The fila- 



ments are united at the bottom, in two bun- 

 dles ; as in the Sweet Pea. 



18. Polyadelphia, or many brotherhoods. The 



filaments are united at the bottom, into three 

 or more bundles. 



19. Syngenesia — contains the compound flowers; 



as the Daisy. See description. 



20. Gynandria, — many stamens growing on the 



pistil itself; as in the Orchis. 



21. Monoecia, or one house. Flowers, some bear- 



ing stamens only, and some pistils, being 

 produced on the same plant. 



22. Dioecia, — two houses. Flowers, some pro- 



ducing stamens only, and others pistils, 

 growing on different plants. 



23. Polygaraia — provides for the only remaining 



case that can possibly occur, and consists of 

 flowers with stamens and pistils in separate, 

 as well as on the same, plants. 



24. Crytogamia, — plants whose flowers are not 



perceptible to the naked eye, though there is 

 good reason to believe that no plant exists 

 without the essential parts which constitute a 

 flower. Ferns, Mosses, and Sea Weeds belong 

 to this class. 



