PREFACE. vti 



A considerable portion of new matter is also intro- 

 duced, which ought perhaps rather to have been ad- 

 dressed to the world through the medium of the uni- 

 versal language of natural science, yet in conformity to 

 the principal intention of the work, and incompliance 

 with the public to whom it is addressed, an uniform 

 language appeared necessary. 



It will readily be perceived that a Synopsis of the Ge- 

 nera is what is chiefly intended by the present publica- 

 tion. And to assist the student more fully in the know- 

 ledge of genera, the essential character has sometimes 

 been extended, after the manner of the celebrated 

 Sprengel's recent Introduction to the Study of Botany. 

 I have also considered it of importance to give a sketch 

 of the habit or mode of vegetation assumed by the 

 generic group in imitation of Xussieu's Genera Planta- 

 rum, from which important assistance on this subject 

 has been perpetually derived throughout the work. 



A view of the Geographical distribution of each ge= 

 nus is also added, not always perhaps sufficiently accu- 

 rate for the existing state of the science, and the rapid 

 progress of modern discovery. 



A brief Catalogue of the species is offered, which 

 maybe considered as supplementary to the recent and 

 extensive Flora of North America by Frederick Pursh, 

 Occasional remarks are added, and new species also pro- 

 posed and introduced, the result of personal collections 

 and observations made from the year 1809 to the pre- 

 sent time, throHghout most of the states and territories 

 composing the Union. 



To the names of species or genera proposed by the 

 author, will be found an asterisk (*) prefixed. To a 



