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Vlll 



INTRODUCTION, 



In most Floras of this country published previously to 

 the British Flora, however excellent in other respects 

 either too much or too little space was devoted to the 

 generic and specific descriptions and synonymes : in the 

 one case swelling the book to a size which entails both 

 expense on the purchaser, and difficulty in consulting the 

 several volumes ; in the other, reducing the technical 

 characters to the shortest possible compass, so that they 

 can scarcely be available, except to persons who are par- 

 tially acquainted with the plant under examination, or 

 with some of its near allies. Between these extremes a 

 middle course was steered, by giving diagnostic remarks 

 where, and where only, they appeared necessary for the 

 discrimination of British species, or such very distinct 

 foreign ones as might possibly be found in this country, 

 and be confounded with them; while the synonymes, 

 with few exceptions, were confined to those of the writer 

 who first described the plant under the name adopted, to 

 a good figure, and in general to a reference to a sino-le 

 Flora only of Great Britain. In the sixth and also^'in 

 the present edition these rules have been slightly de- 

 parted from. So many species have been, of late years, 

 introduced from the Continent with seed-corn, or have 

 escaped from our gardens, and so many of our former 

 well-known species have been split into two or more, 

 that It has been deemed proper to extend, in several in- 

 stances, the characters of both the genera and species, 

 introducing frequently a notice of the more minute parts 

 which a practised botanist requires to examine, but which 

 a student may omit, if his object be merely to attain 

 a knowledge of the name, until he has advanced in the 

 study. Rarely, however, have the genera or species been 

 made to depend on such minute characters, and therefore 

 few alterations have been proposed on the limits of either 

 one or other from what will be found in former editions : 

 when such alteration has taken place in the former, it is 



