III. INTRODUCED Sl'ECIES. 107 



the Coronopus didyma and Stratiotes aloides from the 



native category, in which they had been placed in the 



earher vohimes of this work, in accordance with the 

 usual ideas of English botanists about them. 



4. Vieivs of English Botanists. 



The views of English botanists, in regard to the nati- 

 vity of the species which now compose the flora of 

 Britain, are for the most part very imperfect and empiri- 

 cal ; being guesses emanating from observations made 

 too locally, and too little corrected by comprehensive 

 views in science. Still, the collective opinions of good 

 observers in British botany ought to possess some value, 

 and ought to be allowed their full weight in balancing the 

 probabilities of certain species being aboriginal natives or 

 otherwise. Accordingly, it has been deemed worth while 

 to repeat the list of introduced and distrusted plants, in 

 order to give a condensed summary of the views of 

 various English botanists, both general and local. The 

 names of plants in the second list, subjoined, are repeti- 

 tions of those in the former list. They are followed by 

 three treble columns of abbreviations ; each column being 

 subdivisible into three series. 



The First of the three columns compares the opinions 

 entertained by the Author of this work, — by Mr. C. C. 

 Babington, as set forth in the fourth edition of the 

 Manual of British Botany, — and by Professor Henslow, 

 as indicated in his Catalogue of British Plants, published 

 in 1835. The two latter Authors distinguish the plants 

 into four classes or divisions ; namely, native — possibly 

 introduced — certainly introduced — disregarded or dis- 

 carded from the flora of Britain. The usual terms ap- 

 plied to designate the predial (civil or national) claims of 



