Xvi INTRODUCTION. 



Class I. MONANDRIA, one stamen. 



II. DIANDRIA, two stamens. 



III. TRIANDRIA, three ditto. 



IV. TETRANDRIA, four ditto. 

 V. PENTANDRIA, five ditto. 



VI. HEXANDRIA, six ditto. 

 VII. HEPTANDRIA, seven ditto. 

 VIII. OCTANDRIA, eight ditto. 

 IX. ENNEANDRIA, nine ditto. 

 X. DECANDRIA, ten ditto. 

 XI. DODECANDRIA, twelve to nineteen ditto. 

 The Twelfth and Thirteenth Classes are distinguished 

 by the situation as well as number of the stamens. 

 Class XII. ICOSANDRIA, twenty stamens, or more, in-. 



serted on the calyx. 



XIII. POLYANDRIA, twenty stamens, or more, in- 

 serted on the receptacle. 



The Fourteenth and Fifteenth Classes, by the number 

 and relative proportion of the stamens. 



Class XIV. DIDYNAMIA, four stamens, two longer 



than the others. 

 XV. TETRAD YNAMIA, six stamens, four long, 



and two short. 



The Classes from the Sixteenth to the Nineteenth are 

 distinguished by the combination of the stamens with 

 each other, no account being taken of their number. 

 Class XVI. MONADELPHIA, stamens all united by 



their filaments. 

 XVII. DIADELPHIA, stamens combined by their 



filaments into two sets. 



XVIII. POLYADELPHIA, stamens combined by 



their filaments into three or more sets. 



XIX. SYNGENESIA, stamens united by their 



anthers ; flowers compound. 



in Class XX. GYNANDRIA, the stamens are inserted on 

 the pistil, and so combined with it as 

 to form a central column. 

 The Twenty-first, Twenty-second, and Twenty-third 



