PREFACE. 



considered as aboriginal or even thoroughly naturalized. 

 The attempt to do this is necessary for two seemingly con- 

 tradictory reasons ; namely, the great tendency of many col- 

 lectors to consider as native any plant found growing upon 

 a spot where it is not cultivated ; arid the peculiar scepti- 

 cism of some of our botanists concerning the claims of many 

 local or thinly scattered species to be considered as indige- 

 nous, even when their distribution upon the European con- 

 tinent is not unfavourable to the belief that they may in- 

 habit Britain. It has been recommended that the descrip 

 tions of these excluded species should be placed in an Ap- 

 pendix, but as some of them are not unlikely to be observed 

 by collectors, it is more convenient that they should be 

 arranged with their allies. Those who desire to obtain a 

 complete knowledge of the distribution of our plants should 

 consult Watson's Cybele Britannica. 



A very concise Synopsis of the genera, according to the 

 Linnsean method, is given for the convenience of those 

 botanists who may not be quite familiar with the Natural 

 Orders. 



Dr. Lindley's Vegetable Kingdom being accessible to 

 nearly all the readers of this little work, it has not been 

 considered advisable to introduce detailed descriptions of 

 the Orders ; but in the preparation of the short distinctive 

 characters the author has availed himself of that work, of 

 Dr. Arnott's elaborate treatise contained in the Encyclo- 

 pedia Britannica, oiYtVL^ichsv' & Genera Plantarum, Koch's 

 Synopsis Flora Germanicee, and other works. 



To his botanical friends and correspondents too numerous 

 to record here, he takes this opportunity of returning most 

 sincere thanks for the great assistance they have rendered 



