46 INTRODUCTION. 



The eleventh, eighteenth, and twenty-third classes have generally been 

 omitted since the time of Linnseus, and the genera contained in them distri- 

 buted among the other classes. 



The orders in the first thirteen of these classes are founded on* the number 

 of styles, or where these are wanting, of the stigmas, and are : 



1. Monogynia ; one style to each flower. 



2. Digynia ; two styles. 



3. Trigynia ; three styles. 



4. ' Tetragynia ; four styles. 



5. Pentagynia ; five styles. 

 Number of Styles or J 6. Hexagynia ; six styles. 



Stigmas. \ 7. Heptagynia ; seven styles. 



8. Octagynia ; eight styles. 



9. Emieagynia ; nine styles. 



10. Decagynia ; ten styles. 



11. Dodecagynia ; eleven or twelve styles. 



12. Polygynia ; more than twelve styles. 



The orders of the fourteenth class are only two : 



C Gymnospermia ; having naked seeds. 

 Seeds naked or covered. < Angiospermia ; having the seeds .covered or in 

 { a pericarp. 



The orders of the fifteenth class are also two : 



t^ r r . ( Siliculosa; fruit a silicle, or short pod. 



rorm of fruit. \ <?•,• ' r . ... , r , 



( biliquosa ; fruit a sihque, or long pod. 



The orders of the sixteenth' to the eighteenth, and twentieth to twenty- 

 second classes, are founded on the number of stamens, and. bear the names 

 of the first thirteen classes, as monandria, &c. 



The orders of the nineteenth class are founded on the character of the 

 flowers ; they are : 



Polygamia cequalis ; flowers in heatfs, and all 

 perfect. 



Polygamia superflua ; rays or marginal flowers, 

 pistillate only. 



Polygamiafrustranea ; marginal flowers neutral, 

 the others perfect. 

 Character of flowers. <^ Polygamia necessaria ; marginal flowers pistil- 

 late and fertile, disk flowers staminate and 

 sterile. 



Polygam/ia segregata, ; each flower with its pro- 

 per involucre. 



Monogamia ; flowers solitary, but with united 

 anthers. 



The orders of the twenty-third class are founded on the characters of the 

 two preceding classes. 



Monozcia ; unisexual and perfect flowers on the same plant. 



Diaxia ; the different flowers on different individuals. 



Triozcia ; perfect flowers on one plant, staminate on a second, and pistil- 

 late on a third plant. 



