GENEKA. 79 



6. Hexandria, 6 stamens. 



7. Polyandria, many stamens. 



8. Monadelphia, filaments united into a tube. 

 CLASS 23. POLYGAMIA, stamens and pistils separate 



in some flowers, united in others, either on the same 

 plant, or on two or three distinct ones of the same 

 species. 



Observation. Such difference in the essential organs being 

 moreover accompanied with a difference of structure in the other 

 parts of the flower. Smith. 



This class contains 3 orders. 



1. Monoecia, united flowers, accompanied with bar- 

 ren or fertile, or both, all on one plant. 



2. Dioecia, the different flowers on two different 

 plants. 



3. Trioecia, the different flowers on three different 

 plants. 



CLASS 24. CHYPTOGAMIA, stamens and pistils either 

 not well ascertained, or not to be numbered with 

 any certainty ; contains five orders. 



1. Fillets, Ferns. 



2. Muse?, Mosses. 



3. Hepaticcv, Liverworts. 



4. Mgw, Flags. 



5. Fungi, Mushrooms. 



CHAP. II. 



GENERA AND SPECIES. 



I, Genera and their Characters. 



1. A GENUS consists of a number of plants which 

 agree with each other in their flower and fruit. Will- 

 denow* 



A genus comprehends one or more species, so essen- 

 tially different in formation, nature, and often many 

 adventitious qualities, from other plants, as to consti- 



